Pulled together a modern 1×11 setup on this '93 GT.
I'm just an amateur mechanic so this took a lot of research. Summarizing here to hopefully help others.
Derailleur: Deore M6100. This is a 12s derailleur but is basically the same as the 11s M5100 with IMO a slightly nicer finish. The cable pull is the same so it is fully functional. It has be paired with a 51t cassette, if you have a 46t cassette then you want a Deore M5120 derailleur.
Shifter: SLX M7000. Any Shimano mountain 11s shifter will work, this one was a couple bucks more than the Deore.
Cassette: M5100 11-51T. Found a good deal on this Shimano cassette but there are other options like SunRace to save a few bucks.
Freehub: STX RC 8s hub. Any Shimano 8s-11s hub should work for any 8s-11s cassette. 7s hubs are too short for the cassette, there are some workarounds by omitting one cog but used 8s wheelsets are super common. The 11s cassette on an 8s hub easily fits in the 135mm dropout spacing.
Chain: Shimano, but any Shimano-compatible 11s chain should work.
Cranks & chainring: Deckas narrow-wide 38t chainring on Altus AT10 cranks. Chainline is critical with 1x or you WILL find your chain binding in the highest or lowest gears. Vintage Shimano documentation indicating the chainline is easily found on Google for an particular crankset. Most mid-90s and newer Shimano mountain cranks are 47.5mm from the centreline to the middle chainring position, using a 113mm bottom bracket spindle. This worked perfectly for me, it's just not quite as good looking as using the large chainring position.
Note that early-90s and older cranksets usually need a large 122mm BB spindle to maintain the correct chainline. Sheldon Brown's website has a useful summary of vintage cranksets and compatible bottom bracket sizes.
Setup was super easy using the Shimano instructions for the rear derailleur. I didn't use a hangar alignment tool, but doing so could probably improve shift quality a bit more. These derailleurs are physically HUGE, during setup it will look like it conflicts with the cassette. Don't panic! Once fully set up they don't hit each other, but the clearances are very tight. Precision machinery…
New parts costs in CAD:
Derailleur and shifter: $75 from AliExpress
Cassette and chain: $80 from FB Marketplace
Chainring: $20ish from Amazon
by Immediate-Yard8406
5 Comments
Dumb question, maybe: why isnt a chain guide not needed? Wont the chain fall in the front? Im about to do that change in a bike of mine and Im afraight it will keep falling.
Nice bike/build btw!
Well done! Paint looks mint! Just gave my Timb a Sram X5 9-sp glow-up and that‘s enough for me. Perhaps I‘ll do more in the future.
Yellow-green is also a smooth color choice 😛
Sick build and really appreciate the info!
Thank for the details!
I’m not much of a mechanic, but seeing all the cool bikes in this sub is giving me the itch to restore/modernize a bike.
How did you buy a Deore derailleur off Ali Express? I thought they didn’t sell actually brand name stuff?