Matthew, you got the mechanism right (larger diameter circle in the lever section where the cable is guided through causes more cable to be pulled).
Re: Shimano 600 bar ends - I didn't know about that one but that was my first thought when fiddling with the shifter - can't I grind something away to allow more movement of the lever? A quick look told me this would be complicated and I did not actually want the bar end lever to stick that much further up (when pulling to easier gears) or further down and forward (when in harder gears). Next, I thought of the folks who mix Shimano & Campy components by adjusting the cable routing at the rear derailleur but the mechanics of it didn't quite make sense to me to get enough additional pull. For example, here <https://www.bikeforums.net/bicycle-mechanics/1102658-campy-9s-shifter-derailleur-shimano-cassette-hack.html> among many others. But my kludge seemed the simplest version so long as you have abandoned hope for matching any indexing - friction for the win here. I may try the indexing of my rear shifter (it can work in friction or index mode) just to see if I randomly got it close to the right change of diameter at the lever, but I'm nearly certain that's just for fun and it won't index anymore. I just ordered quite a few jewelry brass bars that are 20*2*1mm, 22.5*2*1mm, and 25*2*1mm for a few bucks and I'll bend them into arches to see if they fit nicely (I suspect I'll need to grind down the width a fraction of a millimeter). If they fit nicely I'd be happy to mail you a few to experiment with. I believe this would work equally well for Shimano bar ends, Microshift friction thumb levers, and others ... basically anything where you can see the cable guide in the lever and add something that will lay under the cable as you pull the lever. While I really like the SRAM GX shifter and Crust gives it a good endorsement in their Turkey Vulture Supreme article, there are quite a few poor reviews out there. The B-screw apparently is weak and bends if pushed much, the derailer itself is a bit loose feeling compared with Shimano (my only other experience) which is another complaint others mention. But for me it's working very nicely - the clutch's impact is exactly what I hoped for compared with the Shimano XT 772 Shadow it replaced: + Significantly quieter while riding. + No chain slap on big bumps. + Strong / more confident shifts - before it would make some noise after a shift and I'd fiddle with the level until it quieted down, but with the GX it's quiet right away. - It is glossy black while I'd prefer completely silver/polished, but, meh, don't really care. The 9-speed chain is happy with this setup, I may try a 10-speed chain just to see if that's improves anything (my memory is that the Crust article said 9spd was fine). I do need to add a couple of links to the chain because the long change and routing of the GX take a bit more than the XT. Abe On Monday, 27 July 2020 at 11:10:07 UTC-7 Matthew P wrote: > I like this stuff and I'm looking to set up something along these lines. > > I was having a hard time grasping it but I think I have it: > The bar end shifter is basically a circle (/spool/reel) wrapping & > releasing cable. > The metal insert increases the radius/diameter/circumference of that > circle. > Now the same travel of the lever - or same change in angle - results in a > larger distance moving on the outside of that circle - and more cable pull. > Common analogy: in one rotation of a spinning record, a point on the edge > of the circle label in the middle travels less linear distance than does a > point on the outer edge of the record. > But they both travel the same number of degrees: 360. > Insert angular velocity stuff here. > > So this is different than the Shimano 600 bar end shifter and the hacked > versions that get more cable pull by having greater movement of the lever - > 180 degree swing or whatever it is. > > I wonder: > > What I can do for thumb shifters. Hack my microshift thumb shifters or do > the lever+(Paul or VO or..?) "Thumby" allow for more options? Maybe I hold > onto my Paul's.. > > So the 9 speed chain is fine with the 10 speed derailer? > Would a 10 speed chain be better? I hear reports of 10 spd chain on 9 spd > casette is good. > > Definitely go with the Sram clutch (rear) derailer instead of a Shimano? > > Thats all I can recall. > Thank you much for sharing. > > -Matthew > San Diego > > > On Sunday, July 26, 2020 at 10:26:53 AM UTC-7, Pancake wrote: >> >> 40 miles today across Napa to Lake Hennessy and back with the new setup: >> great! Significantly quieter and shifts great, better than the XT RD before. >> >> Abe >> >> On Sunday, 26 July 2020 at 05:48:41 UTC-7 ascpgh wrote: >> >>> This is the sort of hack I envisioned for my NOS Mavic/Simplex DT shift >>> levers pertinent for 9-Spd before I accepted that they were going to be >>> just way too dang far down there on a 64cm frame to worry about if or how >>> well they worked. If the functional capstan diameter around which the cable >>> wraps as the lever is rotated was increased.by some amount, the >>> wonderful shifting feel could carry on into the 9-Speed world. >>> >>> I thought about a tube of a particular wall thickness to put the cable >>> through that had a widened end to stop in the lever's recess for the cable >>> end bead. The hole drilled through the lever for the cable enlarged enough >>> to accept both the thickness of the cable and added sleeve. The bead >>> recess enlarged, if needed, to continue acting as the stop for both the >>> cable and the sleeve. Flexibility would help insert through the lever >>> passage, being more rigid and shaped would cause less cable tension to make >>> it take shape as would be operated and cause less "noise" to the shifting >>> function as tension is taken and given during shifts. >>> >>> Andy Cheatham >>> Pittsburgh >>> >>> On Saturday, July 25, 2020 at 1:51:04 PM UTC-4 Bill Lindsay wrote: >>> >>>> Good work. APPROVE. >>>> >>>> In 2020, 3D printing is totally dialed. Somebody with the time and the >>>> CAD station could build a 3D model of an accessory piece that would snap >>>> onto a Silver shifter, increasing the cable pull. Post that model on >>>> Shapeways.com and anybody in the world could click and order it in plastic >>>> or metal. Plastic would be fine. The price of these things are purely >>>> based on the volume of material because that represents how long the >>>> printer is running. Such a piece would only cost a couple bucks to print. >>>> >>>> Charge $15 for it and make a decent margin. That would be cool! I'd buy >>>> one. >>>> >>>> Bill Lindsay >>>> El Cerrito, CA >>>> >>>> On Saturday, July 25, 2020 at 8:53:12 AM UTC-7 Pancake wrote: >>>> >>>>> More corrections: measured with calipers and my estimates were not >>>>> great for the size of the added metal piece: >>>>> >>>>> 25mm long. Could probably be 20mm long and work equally well. >>>>> 1.8mm wide >>>>> 0.8mm thick >>>>> >>>>> -- 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 [email protected]. 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