I like it Bill! When I worked in a machine shop I always found working with acrylic more frustrating than working with metal, but it was great for prototyping stuff (less $$$) if it didn't crack and shatter!
Cheers, Collin, surrounded by IronMen Racers this weekend, in Sacramento On Friday, October 21, 2022 at 1:05:24 PM UTC-7 Bill Lindsay wrote: > Back in May I indicated that I may decide to turn an eccentric spacer for > the Skeleton Key front derailer. I finally went ahead and did that today. > > For a little background here, most Rivendells have a 28.6mm seat tube, and > most Rivendells take a clamp on front derailer. Very few front derailers > today are made with a 28.6mm clamp. Almost all clamp on front derailers > are made with a larger clamp diameter and they come with a plastic spacer > to fit smaller diameter seat tubes. The increments of seat tube diameter > are 1/8", so 28.6mm = 1-1/8" , 31.8mm = 1-1/4", 34.9mm = 1-3/8". The > Skeleton Key front derailer is a 34.9mm model, and it comes with two > different plastic spacers to fit the next two sizes down. The Skeleton Key > front derailer was made for a chain line that is "pretty wide" which would > be great for a Gus/Susie but maybe not so great for a roadish bike. > > I have been preparing to set up an ultra compact, low-Q-factor drivetrain > on my Black Mountain Monster Cross, and the key missing bit is the perfect > front derailer. I like the cage shape of the Skeleton Key, but not the > wide chainline. Since I need to run a plastic spacer anyway to make that > 34.9mm clamp fit my 28.6mm seat tube, I decided to make my own eccentric > spacer on my small lathe. As a first shot I only did about 2.5mm of > eccentricity. Depending on how I position my spacer, I can bring my > Skeleton Key 2.5mm further in or 2.5mm further out. > > Pictures prove I was machining plastic today: > https://www.flickr.com/photos/45758191@N04/albums/72177720303067081 > > Bill Lindsay > El Cerrito, CA > > On Saturday, May 21, 2022 at 9:34:45 AM UTC-7 Bill Lindsay wrote: > >> I will go out on a limb here and predict that Rivendell went ahead and >> checked whether it would work before buying one thousand four hundred of >> them. They are the ones who have to set up their own bikes. >> >> The chainline on the Black Mountain Monster Cross is standard Shimano >> Road Chainline. 43.5mm by the book, or 42mm by my measurement. The >> Skeleton key will either work or I'll be modifying a derailleur. Besides >> the awesome cage shape, I like the 34.9mm clamp. I may decide to turn an >> eccentric spacer set to pull it inboard a few mm. We'll see. Summer >> projects. I'm in the thick of making my own front derailleur as well. >> >> Bill Lindsay >> El Cerrito, CA >> >> On Saturday, May 21, 2022 at 6:56:40 AM UTC-7 John Hawrylak wrote: >> >>> Bill >>> >>> My comment on the Skeleton Key FD chain line was meant for a full >>> triple, not a XD-2 with a guard for the outer ring. For a triple set up as >>> a double, the chainline should not be problem for Skeleton Key FD, since it >>> only needs to move 8 to 10mm to shift the Middle/Inner rings. >>> >>> On the Skeleton Key FD webite, RBW states: "This will work with all >>> Silver cranks" RBW sells a Silver triple with 3 chainrings. The >>> Skeleton Key may have problem with shifting to the Inner ring. >>> >>> What is your Rear chain line on your Monster Cross?? >>> >>> John Hawrylak >>> Woodstown NJ >>> >>> On Saturday, May 21, 2022 at 9:25:27 AM UTC-4 Bill Lindsay wrote: >>> >>>> Also note that this front derailer is intended for a large chainring of >>>> 42 teeth or smaller and 14T of total difference. I doubt there are a lot >>>> of people running an XD2 road triple with a 42 tooth big ring and only 14T >>>> of difference. What would that be: 28/34/42? I doubt there are many >>>> people with that setup. It'll be the perfect FD for a Gus/Susie with a >>>> 34/24 double wrapped around huge tires. >>>> >>>> If there's somebody out there running an XD2 triple with two rings and >>>> a guard, then that person maybe has a 40/26 or something on their Roadini. >>>> >>>> If that person has no front derailer, then they might indeed have a hard >>>> time getting this one to pull the chain to the small ring. >>>> >>>> Anyway, I will give it a look on my Black Mountain Monster Cross, which >>>> will have a 38/24 double on it soon. I've got a few different FD options >>>> for that setup, and I'll give the skeleton key FD a look as I dial it in. >>>> >>>> Bill Lindsay >>>> El Cerrito, CA >>>> >>>> On Saturday, May 21, 2022 at 5:24:50 AM UTC-7 John Hawrylak wrote: >>>> >>>>> Bill >>>>> >>>>> Great report. RBW had these FD's on the website on Fri, 5/20/22, >>>>> and they looked ok to me. >>>>> >>>>> They state a 48.8mm chainline. This seems excessive if you are >>>>> using a 45mmm chainline road triple, like an XD-2. The FD *may not* >>>>> have inward swing to shift to the Inner chain ring. >>>>> >>>>> John Hawrylak >>>>> Woodstown NJ >>>>> >>>>> On Monday, April 25, 2022 at 3:07:06 PM UTC-4 Bill Lindsay wrote: >>>>> >>>>>> On the March 18th email update, Rivendell reported that the container >>>>>> full of frames would also contain *1400 Front Derailers*. They >>>>>> indicated this model will work with all their bikes, but they didn't say >>>>>> exactly what it is, giving it the nickname "skeleton key". I wonder how >>>>>> much space 1,400 front derailers will take up. >>>>>> >>>>>> For those who don't know what's special about "Rivendell Front >>>>>> Derailers", it's a combination of a few things: >>>>>> >>>>>> 1. Rivendells typically have a bit more BB drop than most other bikes >>>>>> 2. Rivendell builds often have a small-sized "big" chainring. Like a >>>>>> 42 big ring, or a 38, or a 34! >>>>>> 3. Rivendells typically have a more laid back Seat Tube Angle than >>>>>> most other bikes >>>>>> >>>>>> the combination of those three things brings the trailing edge of the >>>>>> front derailer down close to the chainstays. So close, that in many >>>>>> cases >>>>>> you flat out can't set up the front derailer "correctly". You have to >>>>>> run >>>>>> it floating way above the chainrings. For a lot of people, this works >>>>>> just >>>>>> fine, and some people actually brag about it. When somebody claims that >>>>>> Combination X is a problem, it's fun to retort "I have Combination X and >>>>>> it's just fine!" >>>>>> >>>>>> Anyhow, 650B bikes have less of this problem (because less BB drop). >>>>>> Still, it's something to think about. I prepared by stocking up on >>>>>> Shimano >>>>>> CX70 Front Derailers when they existed, and now I'm super stingy with >>>>>> those. I'm going to give the "skeleton key" FD a look and may buy a few >>>>>> of >>>>>> those also. As an amateur machinist and maker, I've even dabbled with >>>>>> making my own Front Derailers. >>>>>> >>>>>> Or, you can avoid this altogether and run a 1xDrivetrain! >>>>>> >>>>>> Bill Lindsay >>>>>> El Cerrito, CA >>>>>> >>>>> -- You received this message because you are subscribed to the Google Groups "RBW Owners Bunch" group. To unsubscribe from this group and stop receiving emails from it, send an email to rbw-owners-bunch+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/rbw-owners-bunch/a0fbe93d-1b70-49c5-9bb1-aa9dc35016f8n%40googlegroups.com.
