The Schwinn Cimarron remains one of the more affordable 1980s MTB frames and when a bike is affordable, creativity blossoms. Check out what Alexander did with his 1987 build, featuring the wild and kooky Suntour S-1 rear mech!
I’m a longtime fan of your stuff! You guys have posted some truly amazing bikes over the years, some of my recent fav’s being John’s Yellow Rivendell Bombadil and also Charlie Cunningham’s 2012 personal 29er! Simply exquisite.
I found the frame on eBay while I was in grad school during the pandemic. My interest in bikes blossomed very much at the time. I started reading Grant Peterson’s Blog, and that eventually led to the book “The Dancing Chain” by Frank Berto.
While reading that book I came across some truly fascinating and bizarre derailleurs that I had never heard about before. One of those was the Suntour S-1(RD-S110).
This rear mech was inspired the old French Nivex Derailleur, but had been changed to include a return spring, the addition of an indexing cam, and plastic all the while retaining the original Slant Parallelogram that has served derailleur shifting so well.
It was OEM equipment on 1993 Schwinn CrissCrosses. I quickly found an example on eBay and then got the bright idea add it to the Cimarron Frame. So I had the good people at Transport Cycles in Philadelphia braze a Sunlite Derailleur hanger, which I cut and modified, to the frame.
This project was helped by the fact that Mike Sweatman over at Disraeligears.co.uk published instructions for this gear changer specifying the framebuilding requirements for its use. I painted the braze-on with red nail polish. After the frame mod was done, I built it up!
How does it shift? Alright! This derailleur is strange because there is an indexing cam on the mech itself, not just precise stops in the shifters. I first tried Rivendell’s Silver 2 Shifters, but it was difficult to tell if you were in gear as the micro-ratchet obscured the feel of the indexing cam.
So I switched to some pure-friction Suntour Downtube Shifters, where I let the indexing cam tell me when to stop the shift. It works great.
There are actually many logical reasons to use a rear derailleur in this location (such as protection of the mechanism from falls, aerodynamics and more chain wrap) but after the lengths I went to to try this out, convenience is not one of them!
Anyway, I hope you enjoy this build!
Build Spec:
- 1987 Schwinn Cimarron Frame
- Araya VP-20 26in rims laced to 100 &130mm Shimano Exage hubs
- Shimano 7 Sp 12-28 Casette
- IRD 9 sp Chain
- Shimano 7400 Dura-Ace Front and Rear QR Skewers
- Suntour S-1 (RD-S110) Rear derailleur
- Shimano GRX FD-RX400 Front Derailleur
- Shimano Metrea FC-U5000 Cranks
- Shimano BB-RS500 Bottom Bracket
- Crank Brothers 5050 3 Platform pedals
- TRP CX 8.4 Mini V Brakes
- TRP RRL Alloy Brake Levers
- Suntour Friction Shifters (unsure of model)
- Shimano Dura-ace Bar-end Shift mounts
- Silver Fizik Tempo Microtex Bondcush Bartape
- Velo-Orange Grand Cru Dropbars
- Crust BJ quill stem
- Very Strange JIS Threaded headset needing Lockring tools to tighten
- Blue Lug 1in Brass Spacers
- Velo-Orange Canti-mounted Rando Front Rack
- Rivendell Sackville Trunksack
- Jandd Mountaineering Rear Rack
- Musguard Front Fender
- Velo-Orange Microfiber Touring Saddle
- KingCage Steel Bottle Cage
- Generic Seatpost & QR clamp
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