[RBW] Re: Near-Catastrophic Rim Failure
Hi Ray, I'm glad you're ok. Pics of the rim are really scary. It makes me think that I'll have a look at mine ! I sometimes ride this hill (living in SF) and man, it could have been worst if you were speeding. Take care ! David -- You received this message because you are subscribed to the Google Groups RBW Owners Bunch group. To post to this group, send email to rbw-owners-bunch@googlegroups.com. To unsubscribe from this group, send email to rbw-owners-bunch+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/rbw-owners-bunch?hl=en.
[RBW] Re: Near-Catastrophic Rim Failure
On thought about rim temperature...if the temperature is going to weaken the metal...it's going to more than feel hot on our fingers...it's going to sear them. The rubber bits will melt first. Angus On Dec 7, 1:10 pm, Ray Shine r.sh...@sbcglobal.net wrote: I'm with you! Scary, especially since I ride s many hills and grades. Lots of braking. From: Sean Whelan strummer_...@yahoo.com To: rbw-owners-bunch@googlegroups.com Sent: Wed, December 7, 2011 10:35:17 AM Subject: Re: [RBW] Re: Near-Catastrophic Rim Failure All of this talk has me suddenly worrying about what my many-year old rims with thousands of miles on them would look like in profile when hack-sawed. I think this thread might jump start the Christmas Wheelset sales rush. I, for one, am thinking about it rather seriously. Thanks, Sean --- On Tue, 12/6/11, Grant Petersen gep71...@gmail.com wrote: From: Grant Petersen gep71...@gmail.com Subject: [RBW] Re: Near-Catastrophic Rim Failure To: RBW Owners Bunch rbw-owners-bunch@googlegroups.com Date: Tuesday, December 6, 2011, 2:08 AM Many of you will remember, and all of you can relate to Keith Bontrager's maxim from the late '80s: Light Strong Inexpensive: Pick Two It works to some extent with all bike parts, but even IT can't come to the rescue when the thing is just too light. Do you know the thickness of the braking surface on a typical road rim? It's about 1.2mm. Some are 1.1. That's what fails when rims wear out and blow out. Well...1.1 or 1.2mm looks like nothing, which you consider the abrasion they're subject to and can't possibly avoid. (Disc brakes have their own set of problems, so let's stay on track.) It used to be common practice to inspect brake pads AND rims, but raise you hand if you can remember the last time you did that. How much should a non-racing 700c rim weigh? How thick should the braking surface be, and how tall? How wide should it be? Reasonable answers, kind of, could be: Weight: 500g. Thickness of braking surface: 2.5mm. Height: 11mm. Width: 24mm. But a rim with those specs would weigh about 800g. I believe this because we're having a NOBS rim made to our specs, and it has 1.6mm braking surface, 10.5mm brake surface height, is 25.4 (1) mm wide, and weighs about 650g. It's wider than 24, but way thinner than 2.5, and the 10.511. I think this is a totally reasonable rim, in every way. I wanted 2mm of braking surface, but that would have meant zero buyers, so we settled on the world-record 1.6, bringing the weight down to a near world record 650g, and even though I think it's a perfectly fantastic rim for general nonracing use---touring, trails, commuting, all purpose riding when there's not a timer or a finish line with a banner---I believe we'll end up selling it mostly to guys who weigh 300 pounds and are sick and tired of wheel problems...because most riders like the idea of stout stuff, but don't really want the weight that comes with it. We'll continue to offer other rimsbut this new rim will be the way to go when you truly, really, want a durable rim and wheel. (Anywaythe new stouty won't be available for many months). -- You received this message because you are subscribed to the Google Groups RBW Owners Bunch group. To post to this group, send email to rbw-owners-bunch@googlegroups.com. To unsubscribe from this group, send email to rbw-owners-bunch+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/rbw-owners-bunch?hl=en. -- You received this message because you are subscribed to the Google Groups RBW Owners Bunch group. To post to this group, send email to rbw-owners-bunch@googlegroups.com. To unsubscribe from this group, send email to rbw-owners-bunch+unsubscr...@googlegroups.com. For more options, visit this group athttp://groups.google.com/group/rbw-owners-bunch?hl=en.- Hide quoted text - - Show quoted text - -- You received this message because you are subscribed to the Google Groups RBW Owners Bunch group. To post to this group, send email to rbw-owners-bunch@googlegroups.com. To unsubscribe from this group, send email to rbw-owners-bunch+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/rbw-owners-bunch?hl=en.
Re: [RBW] Re: Near-Catastrophic Rim Failure
All of this talk has me suddenly worrying about what my many-year old rims with thousands of miles on them would look like in profile when hack-sawed. I think this thread might jump start the Christmas Wheelset sales rush. I, for one, am thinking about it rather seriously. Thanks, Sean --- On Tue, 12/6/11, Grant Petersen gep71...@gmail.com wrote: From: Grant Petersen gep71...@gmail.com Subject: [RBW] Re: Near-Catastrophic Rim Failure To: RBW Owners Bunch rbw-owners-bunch@googlegroups.com Date: Tuesday, December 6, 2011, 2:08 AM Many of you will remember, and all of you can relate to Keith Bontrager's maxim from the late '80s: Light Strong Inexpensive: Pick Two It works to some extent with all bike parts, but even IT can't come to the rescue when the thing is just too light. Do you know the thickness of the braking surface on a typical road rim? It's about 1.2mm. Some are 1.1. That's what fails when rims wear out and blow out. Well...1.1 or 1.2mm looks like nothing, which you consider the abrasion they're subject to and can't possibly avoid. (Disc brakes have their own set of problems, so let's stay on track.) It used to be common practice to inspect brake pads AND rims, but raise you hand if you can remember the last time you did that. How much should a non-racing 700c rim weigh? How thick should the braking surface be, and how tall? How wide should it be? Reasonable answers, kind of, could be: Weight: 500g. Thickness of braking surface: 2.5mm. Height: 11mm. Width: 24mm. But a rim with those specs would weigh about 800g. I believe this because we're having a NOBS rim made to our specs, and it has 1.6mm braking surface, 10.5mm brake surface height, is 25.4 (1) mm wide, and weighs about 650g. It's wider than 24, but way thinner than 2.5, and the 10.511. I think this is a totally reasonable rim, in every way. I wanted 2mm of braking surface, but that would have meant zero buyers, so we settled on the world-record 1.6, bringing the weight down to a near world record 650g, and even though I think it's a perfectly fantastic rim for general nonracing use---touring, trails, commuting, all purpose riding when there's not a timer or a finish line with a banner---I believe we'll end up selling it mostly to guys who weigh 300 pounds and are sick and tired of wheel problems...because most riders like the idea of stout stuff, but don't really want the weight that comes with it. We'll continue to offer other rimsbut this new rim will be the way to go when you truly, really, want a durable rim and wheel. (Anywaythe new stouty won't be available for many months). -- You received this message because you are subscribed to the Google Groups RBW Owners Bunch group. To post to this group, send email to rbw-owners-bunch@googlegroups.com. To unsubscribe from this group, send email to rbw-owners-bunch+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/rbw-owners-bunch?hl=en. -- You received this message because you are subscribed to the Google Groups RBW Owners Bunch group. To post to this group, send email to rbw-owners-bunch@googlegroups.com. To unsubscribe from this group, send email to rbw-owners-bunch+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/rbw-owners-bunch?hl=en.
Re: [RBW] Re: Near-Catastrophic Rim Failure
I'm with you! Scary, especially since I ride s many hills and grades. Lots of braking. From: Sean Whelan strummer_...@yahoo.com To: rbw-owners-bunch@googlegroups.com Sent: Wed, December 7, 2011 10:35:17 AM Subject: Re: [RBW] Re: Near-Catastrophic Rim Failure All of this talk has me suddenly worrying about what my many-year old rims with thousands of miles on them would look like in profile when hack-sawed. I think this thread might jump start the Christmas Wheelset sales rush. I, for one, am thinking about it rather seriously. Thanks, Sean --- On Tue, 12/6/11, Grant Petersen gep71...@gmail.com wrote: From: Grant Petersen gep71...@gmail.com Subject: [RBW] Re: Near-Catastrophic Rim Failure To: RBW Owners Bunch rbw-owners-bunch@googlegroups.com Date: Tuesday, December 6, 2011, 2:08 AM Many of you will remember, and all of you can relate to Keith Bontrager's maxim from the late '80s: Light Strong Inexpensive: Pick Two It works to some extent with all bike parts, but even IT can't come to the rescue when the thing is just too light. Do you know the thickness of the braking surface on a typical road rim? It's about 1.2mm. Some are 1.1. That's what fails when rims wear out and blow out. Well...1.1 or 1.2mm looks like nothing, which you consider the abrasion they're subject to and can't possibly avoid. (Disc brakes have their own set of problems, so let's stay on track.) It used to be common practice to inspect brake pads AND rims, but raise you hand if you can remember the last time you did that. How much should a non-racing 700c rim weigh? How thick should the braking surface be, and how tall? How wide should it be? Reasonable answers, kind of, could be: Weight: 500g. Thickness of braking surface: 2.5mm. Height: 11mm. Width: 24mm. But a rim with those specs would weigh about 800g. I believe this because we're having a NOBS rim made to our specs, and it has 1.6mm braking surface, 10.5mm brake surface height, is 25.4 (1) mm wide, and weighs about 650g. It's wider than 24, but way thinner than 2.5, and the 10.511. I think this is a totally reasonable rim, in every way. I wanted 2mm of braking surface, but that would have meant zero buyers, so we settled on the world-record 1.6, bringing the weight down to a near world record 650g, and even though I think it's a perfectly fantastic rim for general nonracing use---touring, trails, commuting, all purpose riding when there's not a timer or a finish line with a banner---I believe we'll end up selling it mostly to guys who weigh 300 pounds and are sick and tired of wheel problems...because most riders like the idea of stout stuff, but don't really want the weight that comes with it. We'll continue to offer other rimsbut this new rim will be the way to go when you truly, really, want a durable rim and wheel. (Anywaythe new stouty won't be available for many months). -- You received this message because you are subscribed to the Google Groups RBW Owners Bunch group. To post to this group, send email to rbw-owners-bunch@googlegroups.com. To unsubscribe from this group, send email to rbw-owners-bunch+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/rbw-owners-bunch?hl=en. -- You received this message because you are subscribed to the Google Groups RBW Owners Bunch group. To post to this group, send email to rbw-owners-bunch@googlegroups.com. To unsubscribe from this group, send email to rbw-owners-bunch+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/rbw-owners-bunch?hl=en. -- You received this message because you are subscribed to the Google Groups RBW Owners Bunch group. To post to this group, send email to rbw-owners-bunch@googlegroups.com. To unsubscribe from this group, send email to rbw-owners-bunch+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/rbw-owners-bunch?hl=en.
[RBW] Re: Near-Catastrophic Rim Failure
So I guess I'll wait to get that disc brake bicycle..the heavy duty rims sound fantastic. On Dec 5, 11:08 pm, Grant Petersen gep71...@gmail.com wrote: Many of you will remember, and all of you can relate to Keith Bontrager's maxim from the late '80s: Light Strong Inexpensive: Pick Two It works to some extent with all bike parts, but even IT can't come to the rescue when the thing is just too light. Do you know the thickness of the braking surface on a typical road rim? It's about 1.2mm. Some are 1.1. That's what fails when rims wear out and blow out. Well...1.1 or 1.2mm looks like nothing, which you consider the abrasion they're subject to and can't possibly avoid. (Disc brakes have their own set of problems, so let's stay on track.) It used to be common practice to inspect brake pads AND rims, but raise you hand if you can remember the last time you did that. How much should a non-racing 700c rim weigh? How thick should the braking surface be, and how tall? How wide should it be? Reasonable answers, kind of, could be: Weight: 500g. Thickness of braking surface: 2.5mm. Height: 11mm. Width: 24mm. But a rim with those specs would weigh about 800g. I believe this because we're having a NOBS rim made to our specs, and it has 1.6mm braking surface, 10.5mm brake surface height, is 25.4 (1) mm wide, and weighs about 650g. It's wider than 24, but way thinner than 2.5, and the 10.511. I think this is a totally reasonable rim, in every way. I wanted 2mm of braking surface, but that would have meant zero buyers, so we settled on the world-record 1.6, bringing the weight down to a near world record 650g, and even though I think it's a perfectly fantastic rim for general nonracing use---touring, trails, commuting, all purpose riding when there's not a timer or a finish line with a banner---I believe we'll end up selling it mostly to guys who weigh 300 pounds and are sick and tired of wheel problems...because most riders like the idea of stout stuff, but don't really want the weight that comes with it. We'll continue to offer other rimsbut this new rim will be the way to go when you truly, really, want a durable rim and wheel. (Anywaythe new stouty won't be available for many months). -- You received this message because you are subscribed to the Google Groups RBW Owners Bunch group. To post to this group, send email to rbw-owners-bunch@googlegroups.com. To unsubscribe from this group, send email to rbw-owners-bunch+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/rbw-owners-bunch?hl=en.
Re: [RBW] Re: Near-Catastrophic Rim Failure
Or go disc with those rims! On Tue, Dec 6, 2011 at 12:39 AM, charlie cl_v...@hotmail.com wrote: So I guess I'll wait to get that disc brake bicycle..the heavy duty rims sound fantastic. On Dec 5, 11:08 pm, Grant Petersen gep71...@gmail.com wrote: Many of you will remember, and all of you can relate to Keith Bontrager's maxim from the late '80s: Light Strong Inexpensive: Pick Two It works to some extent with all bike parts, but even IT can't come to the rescue when the thing is just too light. Do you know the thickness of the braking surface on a typical road rim? It's about 1.2mm. Some are 1.1. That's what fails when rims wear out and blow out. Well...1.1 or 1.2mm looks like nothing, which you consider the abrasion they're subject to and can't possibly avoid. (Disc brakes have their own set of problems, so let's stay on track.) It used to be common practice to inspect brake pads AND rims, but raise you hand if you can remember the last time you did that. How much should a non-racing 700c rim weigh? How thick should the braking surface be, and how tall? How wide should it be? Reasonable answers, kind of, could be: Weight: 500g. Thickness of braking surface: 2.5mm. Height: 11mm. Width: 24mm. But a rim with those specs would weigh about 800g. I believe this because we're having a NOBS rim made to our specs, and it has 1.6mm braking surface, 10.5mm brake surface height, is 25.4 (1) mm wide, and weighs about 650g. It's wider than 24, but way thinner than 2.5, and the 10.511. I think this is a totally reasonable rim, in every way. I wanted 2mm of braking surface, but that would have meant zero buyers, so we settled on the world-record 1.6, bringing the weight down to a near world record 650g, and even though I think it's a perfectly fantastic rim for general nonracing use---touring, trails, commuting, all purpose riding when there's not a timer or a finish line with a banner---I believe we'll end up selling it mostly to guys who weigh 300 pounds and are sick and tired of wheel problems...because most riders like the idea of stout stuff, but don't really want the weight that comes with it. We'll continue to offer other rimsbut this new rim will be the way to go when you truly, really, want a durable rim and wheel. (Anywaythe new stouty won't be available for many months). -- You received this message because you are subscribed to the Google Groups RBW Owners Bunch group. To post to this group, send email to rbw-owners-bunch@googlegroups.com. To unsubscribe from this group, send email to rbw-owners-bunch+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/rbw-owners-bunch?hl=en. -- Cheers, David Redlands, CA ** -- You received this message because you are subscribed to the Google Groups RBW Owners Bunch group. To post to this group, send email to rbw-owners-bunch@googlegroups.com. To unsubscribe from this group, send email to rbw-owners-bunch+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/rbw-owners-bunch?hl=en.
[RBW] Re: Near-Catastrophic Rim Failure
Ray: Is it possible for you to measure the thickness of the failed area? Even a rough idea such as half of original; quarter; or thin as a soda can may be helpful when the rest of us check our rims. Given the dimensions that Grant lists, I should pay a lot more attention to rim wear. My replacement cue has been when they're been banged up enough they won't true up. The current Mavic A719s on my Atlantis rarely need any attention but the braking surfaces have noticeable wear (now that I'm looking). After reading Grant's dimensions for the upcoming Stouty rim, I checked Mavic's website for comparables on the A719. They only list weight (565 grams for 700). tire width (28 to 47), but not rim width or height. IIRC they used to have more detail. The next level down for touring is the A319 @ 595 grams. So Grant's 650 gram is right on target. Most of us are going to mount tires in the 600-900 gram range so another 50-100 grams of rim is worth it for a stronger, longer wearing rim. dougP On Dec 5, 11:08 pm, Grant Petersen gep71...@gmail.com wrote: Many of you will remember, and all of you can relate to Keith Bontrager's maxim from the late '80s: Light Strong Inexpensive: Pick Two It works to some extent with all bike parts, but even IT can't come to the rescue when the thing is just too light. Do you know the thickness of the braking surface on a typical road rim? It's about 1.2mm. Some are 1.1. That's what fails when rims wear out and blow out. Well...1.1 or 1.2mm looks like nothing, which you consider the abrasion they're subject to and can't possibly avoid. (Disc brakes have their own set of problems, so let's stay on track.) It used to be common practice to inspect brake pads AND rims, but raise you hand if you can remember the last time you did that. How much should a non-racing 700c rim weigh? How thick should the braking surface be, and how tall? How wide should it be? Reasonable answers, kind of, could be: Weight: 500g. Thickness of braking surface: 2.5mm. Height: 11mm. Width: 24mm. But a rim with those specs would weigh about 800g. I believe this because we're having a NOBS rim made to our specs, and it has 1.6mm braking surface, 10.5mm brake surface height, is 25.4 (1) mm wide, and weighs about 650g. It's wider than 24, but way thinner than 2.5, and the 10.511. I think this is a totally reasonable rim, in every way. I wanted 2mm of braking surface, but that would have meant zero buyers, so we settled on the world-record 1.6, bringing the weight down to a near world record 650g, and even though I think it's a perfectly fantastic rim for general nonracing use---touring, trails, commuting, all purpose riding when there's not a timer or a finish line with a banner---I believe we'll end up selling it mostly to guys who weigh 300 pounds and are sick and tired of wheel problems...because most riders like the idea of stout stuff, but don't really want the weight that comes with it. We'll continue to offer other rimsbut this new rim will be the way to go when you truly, really, want a durable rim and wheel. (Anywaythe new stouty won't be available for many months). -- You received this message because you are subscribed to the Google Groups RBW Owners Bunch group. To post to this group, send email to rbw-owners-bunch@googlegroups.com. To unsubscribe from this group, send email to rbw-owners-bunch+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/rbw-owners-bunch?hl=en.
Re: [RBW] Re: Near-Catastrophic Rim Failure
Yes, Doug, I will be happy to do that. In fact, last night I went downstairs and disassembled the entire wheel. later today I will take a hacksaw to the rim at several points and try and photograph close in the cross-section cuts. I'll post those pix. Unfortunately, I don't own a point-to-point device to measure the wall thickness, but I'll try and reference scale the pix somehow. From: dougP dougpn...@cox.net To: RBW Owners Bunch rbw-owners-bunch@googlegroups.com Sent: Tue, December 6, 2011 8:18:15 AM Subject: [RBW] Re: Near-Catastrophic Rim Failure Ray: Is it possible for you to measure the thickness of the failed area? Even a rough idea such as half of original; quarter; or thin as a soda can may be helpful when the rest of us check our rims. Given the dimensions that Grant lists, I should pay a lot more attention to rim wear. My replacement cue has been when they're been banged up enough they won't true up. The current Mavic A719s on my Atlantis rarely need any attention but the braking surfaces have noticeable wear (now that I'm looking). After reading Grant's dimensions for the upcoming Stouty rim, I checked Mavic's website for comparables on the A719. They only list weight (565 grams for 700). tire width (28 to 47), but not rim width or height. IIRC they used to have more detail. The next level down for touring is the A319 @ 595 grams. So Grant's 650 gram is right on target. Most of us are going to mount tires in the 600-900 gram range so another 50-100 grams of rim is worth it for a stronger, longer wearing rim. dougP On Dec 5, 11:08 pm, Grant Petersen gep71...@gmail.com wrote: Many of you will remember, and all of you can relate to Keith Bontrager's maxim from the late '80s: Light Strong Inexpensive: Pick Two It works to some extent with all bike parts, but even IT can't come to the rescue when the thing is just too light. Do you know the thickness of the braking surface on a typical road rim? It's about 1.2mm. Some are 1.1. That's what fails when rims wear out and blow out. Well...1.1 or 1.2mm looks like nothing, which you consider the abrasion they're subject to and can't possibly avoid. (Disc brakes have their own set of problems, so let's stay on track.) It used to be common practice to inspect brake pads AND rims, but raise you hand if you can remember the last time you did that. How much should a non-racing 700c rim weigh? How thick should the braking surface be, and how tall? How wide should it be? Reasonable answers, kind of, could be: Weight: 500g. Thickness of braking surface: 2.5mm. Height: 11mm. Width: 24mm. But a rim with those specs would weigh about 800g. I believe this because we're having a NOBS rim made to our specs, and it has 1.6mm braking surface, 10.5mm brake surface height, is 25.4 (1) mm wide, and weighs about 650g. It's wider than 24, but way thinner than 2.5, and the 10.511. I think this is a totally reasonable rim, in every way. I wanted 2mm of braking surface, but that would have meant zero buyers, so we settled on the world-record 1.6, bringing the weight down to a near world record 650g, and even though I think it's a perfectly fantastic rim for general nonracing use---touring, trails, commuting, all purpose riding when there's not a timer or a finish line with a banner---I believe we'll end up selling it mostly to guys who weigh 300 pounds and are sick and tired of wheel problems...because most riders like the idea of stout stuff, but don't really want the weight that comes with it. We'll continue to offer other rimsbut this new rim will be the way to go when you truly, really, want a durable rim and wheel. (Anywaythe new stouty won't be available for many months). -- You received this message because you are subscribed to the Google Groups RBW Owners Bunch group. To post to this group, send email to rbw-owners-bunch@googlegroups.com. To unsubscribe from this group, send email to rbw-owners-bunch+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/rbw-owners-bunch?hl=en. -- You received this message because you are subscribed to the Google Groups RBW Owners Bunch group. To post to this group, send email to rbw-owners-bunch@googlegroups.com. To unsubscribe from this group, send email to rbw-owners-bunch+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/rbw-owners-bunch?hl=en.
Re: [RBW] Re: Near-Catastrophic Rim Failure
Eric: My brother weighs within 10 lb of you and happily rides well built 32 spoke wheels with no long term (let alone short term) problems; he uses no more than 8 cogs in back, but then the same spacing and hubs serve for 9 and 10, no? Or are 8 speed/130 mm hubs stronger than 9-10 speed same? Generally speaking he uses narrow to moderately wide tires: 23 to 38 or so. Years ago when admittedly 20 lb lighter he commuted on 559 wheels built with 28 spokes but carried a (heavy, early '90s Mac) laptop and other kit in a messenger bag; he bunny hopped (he was proud that they stood up to this abuse and announced this fact) those (Mavic rims and hubs) wheels all over the place on his XO-2 with nary a wobbled wheel. His best friend 15 years ago was already well north of 225 and rode 32s constantly (700C) on light steel and CF racing frames -- he'd break frames but not wheels. (He also rode 180 mm Topline Superlight cranks, which he bent and had un-bent by the factory.) On Mon, Dec 5, 2011 at 6:58 PM, EricP ericpl...@aol.com wrote: Agree with Jim here - my rim failure was on a fairly new rim (less than a week old), with less than 100 miles on it. 36 spokes. Just happen to be a stone that cut really sharp and deep. Will admit to having one bike with 32 hole rims. Otherwise, everything is 36 hole. And even there I feel at 225 pounds am probably pushing the envelope and 40 or 48 hole would be more practical. To the OP, sorry but the new photos don't change my mind, but the middle photo is interesting. If you can, take the rim tape off. Would not shock me if the inside of the rim was cracked. Had that happen on a Synergy rim. Almost forgot about that rim failure. Gee, makes me realize I'm harder than most on my rims. Guess that what happens when one is a super heavyweight. Eric Platt St. Paul, MN On Dec 5, 10:10 am, Jim Thill - Hiawatha Cyclery thill@gmail.com wrote: I would disagree that spoke count and symmetry are THAT important. I believe the bigger issue with low-spoke-count wheels is the skinny 125 psi tire they ride on. The reason I say that wheels with fewer spokes and more dish are ok (within reason) is because of modern rim stiffness. I probably wouldn't suggest the MA2 with 24 or 28 spokes for most riders, but with some kind of stiff deep-v style rim, fewer spokes are ok. -- You received this message because you are subscribed to the Google Groups RBW Owners Bunch group. To post to this group, send email to rbw-owners-bunch@googlegroups.com. To unsubscribe from this group, send email to rbw-owners-bunch+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/rbw-owners-bunch?hl=en. -- Patrick Moore Albuquerque, NM For professional resumes, contact Patrick Moore, ACRW http://resumespecialties.com/index.html -- You received this message because you are subscribed to the Google Groups RBW Owners Bunch group. To post to this group, send email to rbw-owners-bunch@googlegroups.com. To unsubscribe from this group, send email to rbw-owners-bunch+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/rbw-owners-bunch?hl=en.
Re: [RBW] Re: Near-Catastrophic Rim Failure
This will be the last time I come to this well over this issue, but here are 3 more pix of the failed rim sawn in cross-section. Pretty alarming! Look here: http://www.flickr.com/photos/8581354@N03/sets/72157628310179371/with/6467935809/ From: dougP dougpn...@cox.net To: RBW Owners Bunch rbw-owners-bunch@googlegroups.com Sent: Tue, December 6, 2011 8:18:15 AM Subject: [RBW] Re: Near-Catastrophic Rim Failure Ray: Is it possible for you to measure the thickness of the failed area? Even a rough idea such as half of original; quarter; or thin as a soda can may be helpful when the rest of us check our rims. Given the dimensions that Grant lists, I should pay a lot more attention to rim wear. My replacement cue has been when they're been banged up enough they won't true up. The current Mavic A719s on my Atlantis rarely need any attention but the braking surfaces have noticeable wear (now that I'm looking). After reading Grant's dimensions for the upcoming Stouty rim, I checked Mavic's website for comparables on the A719. They only list weight (565 grams for 700). tire width (28 to 47), but not rim width or height. IIRC they used to have more detail. The next level down for touring is the A319 @ 595 grams. So Grant's 650 gram is right on target. Most of us are going to mount tires in the 600-900 gram range so another 50-100 grams of rim is worth it for a stronger, longer wearing rim. dougP -- You received this message because you are subscribed to the Google Groups RBW Owners Bunch group. To post to this group, send email to rbw-owners-bunch@googlegroups.com. To unsubscribe from this group, send email to rbw-owners-bunch+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/rbw-owners-bunch?hl=en.
Re: [RBW] Re: Near-Catastrophic Rim Failure
On Dec 6, 2011, at 3:21 PM, Ray Shine wrote: This will be the last time I come to this well over this issue, but here are 3 more pix of the failed rim sawn in cross-section. Pretty alarming! Look here: http://www.flickr.com/photos/8581354@N03/sets/72157628310179371/with/6467935809/ Wow. The asymmetry of the rim wear is astonishing to me. One side is worn practically paper thin and the other side looks untouched. Strange. Do you have a brake pad that doesn't touch the wheel, or a brake pad that drags? -- You received this message because you are subscribed to the Google Groups RBW Owners Bunch group. To post to this group, send email to rbw-owners-bunch@googlegroups.com. To unsubscribe from this group, send email to rbw-owners-bunch+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/rbw-owners-bunch?hl=en.
[RBW] Re: Near-Catastrophic Rim Failure
Ray, Yeah, that sidewall looks pretty thin. Oddly enough, on the photo with the white paper back, the inside of the rim looks thin, not just the outside. Especially below the bead on the section pointed up. Patrick - am one that prefers bike stuff overbuilt, not under. Have had to learn over many years that heavy duty for some is normal to light for me. Always has worked that way. Not abusive, just fat. And well outside the norms for the average bike designer. Will fess up that my single speed is pushing the limits with 32h front and rear. Am hopeful of reliability, but won't be surprised if it isn't. Eric Platt St. Paul, MN On Dec 6, 3:21 pm, Ray Shine r.sh...@sbcglobal.net wrote: This will be the last time I come to this well over this issue, but here are 3 more pix of the failed rim sawn in cross-section. Pretty alarming! Look here: http://www.flickr.com/photos/8581354@N03/sets/72157628310179371/with/... -- You received this message because you are subscribed to the Google Groups RBW Owners Bunch group. To post to this group, send email to rbw-owners-bunch@googlegroups.com. To unsubscribe from this group, send email to rbw-owners-bunch+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/rbw-owners-bunch?hl=en.
Re: [RBW] Re: Near-Catastrophic Rim Failure
Eric and Tim --No. both pads appeared to have equal wear. In fact, there was a small piece of metal embedded in the left side pad. The side-pull brakes are relatively unused, new for just a few months. The wheels came from another bike that was canti-equipped. I just took the front wheel apart, as well. I'm tossing that set of rims for good. From: EricP ericpl...@aol.com To: RBW Owners Bunch rbw-owners-bunch@googlegroups.com Sent: Tue, December 6, 2011 5:22:04 PM Subject: [RBW] Re: Near-Catastrophic Rim Failure Ray, Yeah, that sidewall looks pretty thin. Oddly enough, on the photo with the white paper back, the inside of the rim looks thin, not just the outside. Especially below the bead on the section pointed up. Patrick - am one that prefers bike stuff overbuilt, not under. Have had to learn over many years that heavy duty for some is normal to light for me. Always has worked that way. Not abusive, just fat. And well outside the norms for the average bike designer. Will fess up that my single speed is pushing the limits with 32h front and rear. Am hopeful of reliability, but won't be surprised if it isn't. Eric Platt St. Paul, MN On Dec 6, 3:21 pm, Ray Shine r.sh...@sbcglobal.net wrote: This will be the last time I come to this well over this issue, but here are 3 more pix of the failed rim sawn in cross-section. Pretty alarming! Look here: http://www.flickr.com/photos/8581354@N03/sets/72157628310179371/with/... -- You received this message because you are subscribed to the Google Groups RBW Owners Bunch group. To post to this group, send email to rbw-owners-bunch@googlegroups.com. To unsubscribe from this group, send email to rbw-owners-bunch+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/rbw-owners-bunch?hl=en. -- You received this message because you are subscribed to the Google Groups RBW Owners Bunch group. To post to this group, send email to rbw-owners-bunch@googlegroups.com. To unsubscribe from this group, send email to rbw-owners-bunch+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/rbw-owners-bunch?hl=en.
Re: [RBW] Re: Near-Catastrophic Rim Failure
Interesting how asymmetrical the wear is. Greg On Tue, Dec 6, 2011 at 1:21 PM, Ray Shine r.sh...@sbcglobal.net wrote: This will be the last time I come to this well over this issue, but here are 3 more pix of the failed rim sawn in cross-section. Pretty alarming! Look here: http://www.flickr.com/photos/8581354@N03/sets/72157628310179371/with/6467935809/ -- *From:* dougP dougpn...@cox.net *To:* RBW Owners Bunch rbw-owners-bunch@googlegroups.com *Sent:* Tue, December 6, 2011 8:18:15 AM *Subject:* [RBW] Re: Near-Catastrophic Rim Failure Ray: Is it possible for you to measure the thickness of the failed area? Even a rough idea such as half of original; quarter; or thin as a soda can may be helpful when the rest of us check our rims. Given the dimensions that Grant lists, I should pay a lot more attention to rim wear. My replacement cue has been when they're been banged up enough they won't true up. The current Mavic A719s on my Atlantis rarely need any attention but the braking surfaces have noticeable wear (now that I'm looking). After reading Grant's dimensions for the upcoming Stouty rim, I checked Mavic's website for comparables on the A719. They only list weight (565 grams for 700). tire width (28 to 47), but not rim width or height. IIRC they used to have more detail. The next level down for touring is the A319 @ 595 grams. So Grant's 650 gram is right on target. Most of us are going to mount tires in the 600-900 gram range so another 50-100 grams of rim is worth it for a stronger, longer wearing rim. dougP -- You received this message because you are subscribed to the Google Groups RBW Owners Bunch group. To post to this group, send email to rbw-owners-bunch@googlegroups.com. To unsubscribe from this group, send email to rbw-owners-bunch+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/rbw-owners-bunch?hl=en. -- You received this message because you are subscribed to the Google Groups RBW Owners Bunch group. To post to this group, send email to rbw-owners-bunch@googlegroups.com. To unsubscribe from this group, send email to rbw-owners-bunch+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/rbw-owners-bunch?hl=en.
[RBW] Re: Near-Catastrophic Rim Failure
We had a string of rim failures this summer, maybe 5-6 in just a few weeks (it seemed). All were cases of simple wear, except in Eric's case, where there was an obvious groove likely caused by a foreign object in an otherwise lightly worn rim. One guy had worn out and cracked both rims in a very short time, but he is well known at the shop for his rapid pace of brake pad wear (I suspect he brakes subconsciously at every intersection or any long-shot potential for danger). Rims are definitely a wear item. I've read claims by old-timers like Jobst Brandt that suggest rims should last tens of thousands of miles. IME, that is generally not the case. Perhaps modern rim alloys are softer, or maybe brake pads are different, or perhaps there are more bike commuters out in foul weather nowadays? -- You received this message because you are subscribed to the Google Groups RBW Owners Bunch group. To view this discussion on the web visit https://groups.google.com/d/msg/rbw-owners-bunch/-/mHV8kmgeQKAJ. To post to this group, send email to rbw-owners-bunch@googlegroups.com. To unsubscribe from this group, send email to rbw-owners-bunch+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/rbw-owners-bunch?hl=en.
Re: [RBW] Re: Near-Catastrophic Rim Failure
On Dec 5, 2011, at 2:35 AM, Jim Thill - Hiawatha Cyclery wrote: We had a string of rim failures this summer, maybe 5-6 in just a few weeks (it seemed). All were cases of simple wear, except in Eric's case, where there was an obvious groove likely caused by a foreign object in an otherwise lightly worn rim. One guy had worn out and cracked both rims in a very short time, but he is well known at the shop for his rapid pace of brake pad wear (I suspect he brakes subconsciously at every intersection or any long-shot potential for danger). Rims are definitely a wear item. I've read claims by old-timers like Jobst Brandt that suggest rims should last tens of thousands of miles. IME, that is generally not the case. Perhaps modern rim alloys are softer, or maybe brake pads are different, or perhaps there are more bike commuters out in foul weather nowadays? With the MA2 (non-anodized, spoke nipple sockets) and 36 spokes on a 5 speed/120 OLN or 6 speed 126 OLN wheel that was possible. With 8/9/10 speed wheels on 130 mm it ain't gonna happen, especially with the minimal spoking patterns now considered normal. Modern road frame designs aren't going to accommodate the 145 mm OLN that would be needed to sufficiently reduce dish. Bike components are no longer durable goods in the eyes of the bike industry. They think it's just fine for you to spend $5000 every 2-4 years to replace your bike. What, a bike should last longer than that? Pah! My All-Rounder has 135 mm OLN with a 7 speed Phil hub and freewheel (Jim's shop knows this wheel well, they spent about 4 hours trying to get a freewheel off of it, finally resorting to disassembling the freewheel and cutting it off with an angle grinder. I didn't ask for the details. But I digress). The original build was in 1996 with a Sun CR-16 rim (polished, no eyelets). The dish is only about 2 mm. That rim lasted for 14 years/30,000 miles until it finally developed a crack by one of the spoke holes. I've never broken a spoke on that wheel; now I can't remember if I used new spokes when I rebuilt that wheel or taped the new rim (CR-18) to the old and transferred the spokes to the new rim since the ERD is within a mm between the two. I think the key points of rim longevity are (1) number of spokes, (2) less dish is much, much better and no dish is perfect, (3) minimizing braking wear. The last point is going to be dependent on a lot of factors- if you live in a mountainous rainy area you're going to wear through rims faster than a fair weather rider in Kansas who can go for a 50 mile ride without touching the brakes except at the very end of the ride. Many modern rims have some kind of wear indicator built into the braking surface. -- You received this message because you are subscribed to the Google Groups RBW Owners Bunch group. To post to this group, send email to rbw-owners-bunch@googlegroups.com. To unsubscribe from this group, send email to rbw-owners-bunch+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/rbw-owners-bunch?hl=en.
[RBW] Re: Near-Catastrophic Rim Failure
Like everybody else, I am glad you are OK. Next to a fork failure, a rim blowout is perhaps the worst mechanical failure. If you use your rear brake for slowing, you'll wear out rear rims in quick succession. Rear rims collect much more road grit than front ones (spray from front wheel). The grit works like a very effective abrasive, and will wear through your rim quickly. It's easy to check whether this is the culprit: Take a hacksaw and cut your rim in half in one of the places where it still is intact. Clean off the burrs with a file. You will see how much material there was initially by looking at the places where the brake blocks did not touch. Compare that to the brake track. You also should be able to see any gouges from sharp stones, as others have suggested. For every rider, it is a good practice to check rim wear from time to time. Some newer rims have built-in marks. Once these disappear, you should replace the rim. Also, most rims start bulging outward when they get seriously thin. You can see that with calipers. If the sides of your rim no longer are parallel, then the rim is getting dangerously thin. Overheating rims doesn't appear to be a problem. You tire will melt before you damage the rim, and blow off. (That is very dangerous, but the tire being the weak link, the rim is unlikely to explode from overheating.) Jan Heine Editor Bicycle Quarterly http://www.bikequarterly.com Follow our blog at http://janheine.wordpress.com/ -- You received this message because you are subscribed to the Google Groups RBW Owners Bunch group. To post to this group, send email to rbw-owners-bunch@googlegroups.com. To unsubscribe from this group, send email to rbw-owners-bunch+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/rbw-owners-bunch?hl=en.
[RBW] Re: Near-Catastrophic Rim Failure
Agree with Jim here - my rim failure was on a fairly new rim (less than a week old), with less than 100 miles on it. 36 spokes. Just happen to be a stone that cut really sharp and deep. Will admit to having one bike with 32 hole rims. Otherwise, everything is 36 hole. And even there I feel at 225 pounds am probably pushing the envelope and 40 or 48 hole would be more practical. To the OP, sorry but the new photos don't change my mind, but the middle photo is interesting. If you can, take the rim tape off. Would not shock me if the inside of the rim was cracked. Had that happen on a Synergy rim. Almost forgot about that rim failure. Gee, makes me realize I'm harder than most on my rims. Guess that what happens when one is a super heavyweight. Eric Platt St. Paul, MN On Dec 5, 10:10 am, Jim Thill - Hiawatha Cyclery thill@gmail.com wrote: I would disagree that spoke count and symmetry are THAT important. I believe the bigger issue with low-spoke-count wheels is the skinny 125 psi tire they ride on. The reason I say that wheels with fewer spokes and more dish are ok (within reason) is because of modern rim stiffness. I probably wouldn't suggest the MA2 with 24 or 28 spokes for most riders, but with some kind of stiff deep-v style rim, fewer spokes are ok. -- You received this message because you are subscribed to the Google Groups RBW Owners Bunch group. To post to this group, send email to rbw-owners-bunch@googlegroups.com. To unsubscribe from this group, send email to rbw-owners-bunch+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/rbw-owners-bunch?hl=en.
Re: [RBW] Re: Near-Catastrophic Rim Failure
Lay a straightedge against the rim braking surface. As it wears, it will become concave. If it has started to actually bulge then it should be immediately removed from service and replaced because it is in active failure mode. However, the concavity can make it look like the rim is bulging when it isn't. The problem with trying to gauge wear by measuring is that most rim makers do not publish wall thickness. Here's a photo of a rim sectioned like Jan suggests which gives a very graphic demonstration of sidewall wear. The amount of wear can be quite surprising! http://pardo.net/bike/pic/fail-026/000.html On Dec 5, 2011, at 9:26 AM, Jan Heine wrote: For every rider, it is a good practice to check rim wear from time to time. Some newer rims have built-in marks. Once these disappear, you should replace the rim. Also, most rims start bulging outward when they get seriously thin. You can see that with calipers. If the sides of your rim no longer are parallel, then the rim is getting dangerously thin. -- You received this message because you are subscribed to the Google Groups RBW Owners Bunch group. To post to this group, send email to rbw-owners-bunch@googlegroups.com. To unsubscribe from this group, send email to rbw-owners-bunch+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/rbw-owners-bunch?hl=en.
Re: [RBW] Re: Near-Catastrophic Rim Failure
Thanks for that link. I looked at all of those page links and the photos show damage exactly like mine. I think you guys are correct. I am going to cut a section out and I'll post another two pix or so. Still, what's with that bulge? From: Tim McNamara tim...@bitstream.net To: rbw-owners-bunch@googlegroups.com Sent: Mon, December 5, 2011 6:20:36 PM Subject: Re: [RBW] Re: Near-Catastrophic Rim Failure Lay a straightedge against the rim braking surface. As it wears, it will become concave. If it has started to actually bulge then it should be immediately removed from service and replaced because it is in active failure mode. However, the concavity can make it look like the rim is bulging when it isn't. The problem with trying to gauge wear by measuring is that most rim makers do not publish wall thickness. Here's a photo of a rim sectioned like Jan suggests which gives a very graphic demonstration of sidewall wear. The amount of wear can be quite surprising! http://pardo.net/bike/pic/fail-026/000.html On Dec 5, 2011, at 9:26 AM, Jan Heine wrote: For every rider, it is a good practice to check rim wear from time to time. Some newer rims have built-in marks. Once these disappear, you should replace the rim. Also, most rims start bulging outward when they get seriously thin. You can see that with calipers. If the sides of your rim no longer are parallel, then the rim is getting dangerously thin. -- You received this message because you are subscribed to the Google Groups RBW Owners Bunch group. To post to this group, send email to rbw-owners-bunch@googlegroups.com. To unsubscribe from this group, send email to rbw-owners-bunch+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/rbw-owners-bunch?hl=en. -- You received this message because you are subscribed to the Google Groups RBW Owners Bunch group. To post to this group, send email to rbw-owners-bunch@googlegroups.com. To unsubscribe from this group, send email to rbw-owners-bunch+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/rbw-owners-bunch?hl=en.
[RBW] Re: Near-Catastrophic Rim Failure
This post makes me queasy. I put old wheels on my AHH frame that I got just a few months ago. Figuring I'll save a little cash up front and buy nice wheels later. The little wear indicator isn't showing yet but the rim braking surface is well worn. Think I'll be stepping up the hunt for new wheels. Glad you're ok. --Andy -- You received this message because you are subscribed to the Google Groups RBW Owners Bunch group. To view this discussion on the web visit https://groups.google.com/d/msg/rbw-owners-bunch/-/zFVGKNdTRcwJ. To post to this group, send email to rbw-owners-bunch@googlegroups.com. To unsubscribe from this group, send email to rbw-owners-bunch+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/rbw-owners-bunch?hl=en.
[RBW] Re: Near-Catastrophic Rim Failure
Many of you will remember, and all of you can relate to Keith Bontrager's maxim from the late '80s: Light Strong Inexpensive: Pick Two It works to some extent with all bike parts, but even IT can't come to the rescue when the thing is just too light. Do you know the thickness of the braking surface on a typical road rim? It's about 1.2mm. Some are 1.1. That's what fails when rims wear out and blow out. Well...1.1 or 1.2mm looks like nothing, which you consider the abrasion they're subject to and can't possibly avoid. (Disc brakes have their own set of problems, so let's stay on track.) It used to be common practice to inspect brake pads AND rims, but raise you hand if you can remember the last time you did that. How much should a non-racing 700c rim weigh? How thick should the braking surface be, and how tall? How wide should it be? Reasonable answers, kind of, could be: Weight: 500g. Thickness of braking surface: 2.5mm. Height: 11mm. Width: 24mm. But a rim with those specs would weigh about 800g. I believe this because we're having a NOBS rim made to our specs, and it has 1.6mm braking surface, 10.5mm brake surface height, is 25.4 (1) mm wide, and weighs about 650g. It's wider than 24, but way thinner than 2.5, and the 10.511. I think this is a totally reasonable rim, in every way. I wanted 2mm of braking surface, but that would have meant zero buyers, so we settled on the world-record 1.6, bringing the weight down to a near world record 650g, and even though I think it's a perfectly fantastic rim for general nonracing use---touring, trails, commuting, all purpose riding when there's not a timer or a finish line with a banner---I believe we'll end up selling it mostly to guys who weigh 300 pounds and are sick and tired of wheel problems...because most riders like the idea of stout stuff, but don't really want the weight that comes with it. We'll continue to offer other rimsbut this new rim will be the way to go when you truly, really, want a durable rim and wheel. (Anywaythe new stouty won't be available for many months). -- You received this message because you are subscribed to the Google Groups RBW Owners Bunch group. To post to this group, send email to rbw-owners-bunch@googlegroups.com. To unsubscribe from this group, send email to rbw-owners-bunch+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/rbw-owners-bunch?hl=en.
[RBW] Re: Near-Catastrophic Rim Failure
First off - glad you are okay. Possibly could have been an overheated rim. On the other hand, had a similar rim failure early this year on my LHT (which is also a winter commuter). My LBS concluded that a small stone (or something similar) got stuck in a brake pad and quickly cut a deep groove in the wall of the rim. Which then failed. Might want to check your pads and make sure nothing is embedded and waiting to chew another rim apart. Eric Platt St. Paul, MN On Dec 4, 6:35 pm, Ray r.sh...@sbcglobal.net wrote: Took a nice ride across the bridge and up to Hawk Hill, planning to get home in time to catch the 49er game at the end of 1st quarter. I didn't make it. My rear rim blew out as I took a slow (translated: continuous braking down 18% descent to hold speed at 10(-)mph.) descent down back side of Conzumel Road toward the lighthouse. Because I crashed on the same section of this road in January and broke my collarbone, I have been taking this descent extra carefully and slowly now that I am back on the bike. Just as I was in the last tight turn before the road levels out to a reasonable grade, my rear tire popped and blew out. I managed to stay upright and bring it to a stop against a bank. There, I discovered that my rear rim blew out and a 18 section of the sidewall bead just blew out and tangled up in the spokes and chainstay. The wheel rims are Araya. Just prior to leaving home, I pumped up the rear Pasella x32 to 85 pounds. The wheels are about three years old. No prior wheel trauma. Could this failure resulted from the long braking over-heating the rim and the pressure blowing it out? Seems strange, but, can that happen? Here are the pix: http://www.flickr.com/photos/8581354@N03/sets/72157628281638979/with/... -- You received this message because you are subscribed to the Google Groups RBW Owners Bunch group. To post to this group, send email to rbw-owners-bunch@googlegroups.com. To unsubscribe from this group, send email to rbw-owners-bunch+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/rbw-owners-bunch?hl=en.
[RBW] Re: Near-Catastrophic Rim Failure
I've seen maybe fifteen rims fail this way, and ever time it's been caused by rock-wear, as Eric suggested. That's not to say nothing else can cause it, but that is (in my experience) the most common (100 percent) reason for it. Rim makers and tire makers build more wiggle- room into their stuffs than...an extra five psi. Close inspection would tell the story---whether the chunk-o-rim just blew out suddenly (catastrophically means suddenly and complete, in this context), or whether the rim had been scored deep by Foreign Object for a while, and just couldn't take it anymore. Conzelman (note spelling) is a beautiful road, as neat as any in California (maybe the world). Too short, one way, and what a dropoff.Glad you're OK, Ray. On Dec 4, 4:35 pm, Ray r.sh...@sbcglobal.net wrote: Took a nice ride across the bridge and up to Hawk Hill, planning to get home in time to catch the 49er game at the end of 1st quarter. I didn't make it. My rear rim blew out as I took a slow (translated: continuous braking down 18% descent to hold speed at 10(-)mph.) descent down back side of Conzumel Road toward the lighthouse. Because I crashed on the same section of this road in January and broke my collarbone, I have been taking this descent extra carefully and slowly now that I am back on the bike. Just as I was in the last tight turn before the road levels out to a reasonable grade, my rear tire popped and blew out. I managed to stay upright and bring it to a stop against a bank. There, I discovered that my rear rim blew out and a 18 section of the sidewall bead just blew out and tangled up in the spokes and chainstay. The wheel rims are Araya. Just prior to leaving home, I pumped up the rear Pasella x32 to 85 pounds. The wheels are about three years old. No prior wheel trauma. Could this failure resulted from the long braking over-heating the rim and the pressure blowing it out? Seems strange, but, can that happen? Here are the pix: http://www.flickr.com/photos/8581354@N03/sets/72157628281638979/with/... -- You received this message because you are subscribed to the Google Groups RBW Owners Bunch group. To post to this group, send email to rbw-owners-bunch@googlegroups.com. To unsubscribe from this group, send email to rbw-owners-bunch+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/rbw-owners-bunch?hl=en.
Re: [RBW] Re: Near-Catastrophic Rim Failure
Well, kind of glad to hear that -- only 15. I need a new rim now anyway, so maybe I'll BART out and show you guys the wheel and the failed section pretty soon. You guys -- and maybe Rich -- might offer a conclusion that would benefit some other folks on this list. (By the way, I'm not suggesting definitively that Rich built this wheel. I actually don't recall where I got it.) From: grant grant...@gmail.com To: RBW Owners Bunch rbw-owners-bunch@googlegroups.com Sent: Sun, December 4, 2011 6:25:09 PM Subject: [RBW] Re: Near-Catastrophic Rim Failure I've seen maybe fifteen rims fail this way, and ever time it's been caused by rock-wear, as Eric suggested. That's not to say nothing else can cause it, but that is (in my experience) the most common (100 percent) reason for it. Rim makers and tire makers build more wiggle- room into their stuffs than...an extra five psi. Close inspection would tell the story---whether the chunk-o-rim just blew out suddenly (catastrophically means suddenly and complete, in this context), or whether the rim had been scored deep by Foreign Object for a while, and just couldn't take it anymore. Conzelman (note spelling) is a beautiful road, as neat as any in California (maybe the world). Too short, one way, and what a dropoff.Glad you're OK, Ray. On Dec 4, 4:35 pm, Ray r.sh...@sbcglobal.net wrote: Took a nice ride across the bridge and up to Hawk Hill, planning to get home in time to catch the 49er game at the end of 1st quarter. I didn't make it. My rear rim blew out as I took a slow (translated: continuous braking down 18% descent to hold speed at 10(-)mph.) descent down back side of Conzumel Road toward the lighthouse. Because I crashed on the same section of this road in January and broke my collarbone, I have been taking this descent extra carefully and slowly now that I am back on the bike. Just as I was in the last tight turn before the road levels out to a reasonable grade, my rear tire popped and blew out. I managed to stay upright and bring it to a stop against a bank. There, I discovered that my rear rim blew out and a 18 section of the sidewall bead just blew out and tangled up in the spokes and chainstay. The wheel rims are Araya. Just prior to leaving home, I pumped up the rear Pasella x32 to 85 pounds. The wheels are about three years old. No prior wheel trauma. Could this failure resulted from the long braking over-heating the rim and the pressure blowing it out? Seems strange, but, can that happen? Here are the pix: http://www.flickr.com/photos/8581354@N03/sets/72157628281638979/with/... -- You received this message because you are subscribed to the Google Groups RBW Owners Bunch group. To post to this group, send email to rbw-owners-bunch@googlegroups.com. To unsubscribe from this group, send email to rbw-owners-bunch+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/rbw-owners-bunch?hl=en. -- You received this message because you are subscribed to the Google Groups RBW Owners Bunch group. To post to this group, send email to rbw-owners-bunch@googlegroups.com. To unsubscribe from this group, send email to rbw-owners-bunch+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/rbw-owners-bunch?hl=en.
[RBW] Re: Near-Catastrophic Rim Failure
Looks like thin side wall issues. Same thing happened to me lucky not on a decent down. On Dec 4, 4:35 pm, Ray r.sh...@sbcglobal.net wrote: Took a nice ride across the bridge and up to Hawk Hill, planning to get home in time to catch the 49er game at the end of 1st quarter. I didn't make it. My rear rim blew out as I took a slow (translated: continuous braking down 18% descent to hold speed at 10(-)mph.) descent down back side of Conzumel Road toward the lighthouse. Because I crashed on the same section of this road in January and broke my collarbone, I have been taking this descent extra carefully and slowly now that I am back on the bike. Just as I was in the last tight turn before the road levels out to a reasonable grade, my rear tire popped and blew out. I managed to stay upright and bring it to a stop against a bank. There, I discovered that my rear rim blew out and a 18 section of the sidewall bead just blew out and tangled up in the spokes and chainstay. The wheel rims are Araya. Just prior to leaving home, I pumped up the rear Pasella x32 to 85 pounds. The wheels are about three years old. No prior wheel trauma. Could this failure resulted from the long braking over-heating the rim and the pressure blowing it out? Seems strange, but, can that happen? Here are the pix: http://www.flickr.com/photos/8581354@N03/sets/72157628281638979/with/... -- You received this message because you are subscribed to the Google Groups RBW Owners Bunch group. To post to this group, send email to rbw-owners-bunch@googlegroups.com. To unsubscribe from this group, send email to rbw-owners-bunch+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/rbw-owners-bunch?hl=en.
