I recently upgraded my favorite bike - a Retrotec Funduro, made by Curtis Inglis - to an Eagle GX drivetrain with 32-tooth front ring and 12 gears in the back, 10 through 50 teeth. I swapped out an X1 drivetrain, also with a 32-tooth front ring, but with 10-42 on the back. I also swapped out the tires; WTB Ranger 2.8 "Tough/Fast" casing & rubber, which was getting bald and slippery in the back, but with as yet no cuts or punctures, for Maxxis Minion DHF 2.8 front and DHR 2.8 rear.
The Funduro is built around Boost, with wider hubs and an offset chain ring to give more clearance to "plus" tire sizes while maintaining a short chain stay and good chain line. This version of the Eagle GX kit in a box had the Boost version of the crank set, where the chain ring has 3mm of extra out-board offset.
Installation went fine, with two hiccups; one, the limit screws on the rear derailleur were not set to Boost spacing, meaning I sent the chain into the spokes a few too many times before I got the high-low limits set, and two, even with a straight derailleur hanger, there's still just a hint of complaint in one of the middle-low gears. I run full housing from shifter to derailleur, and had to increase cable tension on the second ride, getting the sifting near perfect. The kit came with a red plastic b-tension adjustment tool that was pretty handy. I followed the chain-length instructions on page 10 of the current SRAM User Manual Cassettes and Chains, page 10, but it ended up being one link too long, so I took it out before setting the master link in place. (Note that the master link is directional, outside link should have an arrow facing the direction of pedaling, but this does cause me some anxiety on the Escher spectrum, since inside link points in the opposite direction of chain travel during pedaling. Janus had this problem.) I still have a slight hint of derailment, audibly in about the 5th gear from lowest, but it hasn't jumped yet. I'll put an alignment tool on the hanger before next ride. Could also be imperfect tension. Installing the shifter was so easy; uninstalled the old one from the Matchmaker brake / shifter clamp, installed the new one. I always use the right-most hole on the shifter, because I have big hands and want the shifter as inboard (left) from my grip as possible. That means removing the little placeholder screw that's usually in the right hole into the left hole, so that I can attach the shifter to the mount with the right hole. Sorry, no pics, but if you have a SRAM shifter, look for yourself.
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| Yes, 50t low gear dwarfs the 180mm rotor. |
The tires are bigger, chunkier, probably heavier, and at least in the front, have stock-car sized MAXXIS lettering. Looks so cool, and at 15psi front, 17psi rear tubeless on Derby 50mm-wide rims, ride amazingly. Any more pressure and they don't perform well. I'm 225lbs.
Traction is unreal; climbing, descending, cornering. On climbs, with the 50-tooth low I feel like I can clean almost anything. There's a tough, local climb that is long, steep and cleaning it requires a combination of strength, balance, traction and grit. I rode it seated, didn't have to try as hard as normal, beyond making sure my pedals didn't hit the sides of the rut at the top. I find myself braking on downhill corners well before I need to, which means I need to recalibrate my brain to match what this bike can do. My favorite bike is now better.
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| Rertrotec in front of Joaquin Miller's Abbey |
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