I'm with you! Scary, especially since I ride soooo many hills and grades. Lots of braking.
________________________________ From: Sean Whelan <[email protected]> To: [email protected] 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 <[email protected]> wrote: > From: Grant Petersen <[email protected]> > Subject: [RBW] Re: Near-Catastrophic Rim Failure > To: "RBW Owners Bunch" <[email protected]> > 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 10.5<11. 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 rims....but this new rim will > be the way > to go when you truly, really, want a durable rim and > wheel. > (Anyway....the 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 [email protected]. > To unsubscribe from this group, send email to > [email protected]. > 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 [email protected]. To unsubscribe from this group, send email to [email protected]. 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 [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/rbw-owners-bunch?hl=en.
