Advice needed. I just picked up a very nice GT Force Carbon in great condition but I am slightly confused by what the previous owner has done with the gears. It’s running Shimano SLX which is obviously 12 speed but the rear cassette (can’t see a brand) only has 10 cogs. The front cranks and cog are Race Face. I had it out today for first test ride and the gear action isn’t great – sometimes not changing at all when pressed, or jumping multiple gears. Any advice welcome. I’m thinking here it should have the proper Shimano cassette to match the gearset ?
by jizzyjugsjohnson
7 Comments
Which specific model of SLX shifter does it have? Post a pic of that if you’re not sure.
Welcome to the land of Frankenstein second hand bikes put together by amateurs at best. Perhaps the thieves at worst. The costs of avoiding a bike shop (where you’re not going to get mismatched parts or no service. )
Cant deal with it yourself then take it to a shop and let them deal with the clusterfuck by changing the cassette and or chain. Maybe the shifters. Then a full tune to make sure it all works because there are other things likely mismatched or misaligned. Out of line or not set up. That will cost you maybe $300 or $400 for a working bike if you’re lucky
The problem is NOBODY ever has the bike inspected by a shop before they buy cheaper second hand throw together Frankenstein monsters. They think they saved money by buying used . Think twice next time? And let me guess you bought it in a hurry and didnt even THINK of test riding it first to see what was fucked up about it and cant return it either. Wow . .joined the legion of used purchasers who then want other people besides the seller to unfuck it. Sorry 😔
SLX is not only 12 speed, also in 10&11, maybe 9 as well.
It looks like he used a third party wide range 10sp cassette and must have put a 10 speed shifter up front. The shifting on a shimano 12 speed (or deore 11 sp) is really enhanced by the use of a shimano cassette and chain. The crankset is irrelevant –so long as the chainring (cog) is compatible with a 12 speed shimano chain (assuming that is what you are using).
Option 1) assuming that you can change out the freehub body on the rear hub to micro spline standard then get a 12 speed shimano cassette (SLX or Deore) with chain (highly recommend springing for m8100 series chain but 7100 (slx) and 6100 (deore) will work fine and 6100/7100/8100 shifter. But verify that your chainring will work first. If not you can replace the chainring or go for option 2
Option 2) 11 Speed deore cassette (m5100) and shifter and 11sp chain. You do not have to replace the freehub body becasue it uses the oolder HG standard and you still keep the derailleur because the 5100 and 6100 rear mech are identical.
If you want to run Shimano MTB 12-speed, the hub will need a microspline freehub body. Currently, there’s almost definitely an HG freehub body installed under that 10-speed cassette.
So to run a full Shimano 12-speed system you’ll need a microspline body (if one is available for that model of hub) and a cassette (Deore cassettes shift just as well as SLX and XT, they’re just a little heavier).
Again, assuming that shifter is 12 speed, an alternative option is to install an SX/NX Eagle (PG 1230) cassette onto the HG body. The shifting won’t be super slick, but it’ll work ‘good enough’ and be cheaper, giving you time to save for the full Shimano system.
EDIT: you’ll need a 12-speed chain, of course.
Does SLX has “12s” written on it in general? Because i can not find it on other SLX photos.
Also, why the end of the shifting cable is so long?
I run slx rd on my fatbike with the sram nx cassette. Works great, uses hg hub. https://www.jensonusa.com/sram-nx-eagle-1230-cassette-2023-oe-packaged-2?section=sfdetails
Do you know if the shifter is 12 speed?