prj71

I'm thinking the manufactures are putting whatever they can on the bikes just so they can sell a complete bike.

Darth Lefty 

Maybe? longtime forum member and shop owner psimet was announcing the arrival of the long anticipated glut last week over in the roadie forum

3speed

I wonder if that’s the case too. But then they shouldn’t be charging higher-end prices when they ended up specing lower-end parts. A Sram SX bike shouldn’t cost too terribly much.
Some of the Trek hybrids are coming in with “Power” brand brakes that are just terrible. They’re basically what you get if you find the cheapest hydraulic brakes Amazon has to offer. Yet they still charge what the bike cost with original spec of Shimano or at least Tektro brakes.

TJClay

For $600 SRAM AXS is incredible. My Turbo Levo came with SLX and never shifted perfectly. Easy swap and it shifts perfectly every single time.

LTC19951025

The $600 SRAM GX AXS is very smooth when shifting gears

geo8086

OP here. I wanted to update this thread with my ultimate solution to my OEM SRAM SX 12-speed shifting problem on my 2021 Specialized Rockhopper Expert:

I ordered a Shimano SLX derailleur and shifter from Singapore on e-bay (they took over 2 months to arrive), installed them on my bike, and now the bike shifts perfectly with the Shimano SLX derailleur & shifter and SRAM SX cassette. I was worried about mixing vendors like this, but it worked perfectly.

I still can't peddle backwards in my granny-gear without the chain falling off, but I wasn't expecting a derailleur to fix that. I think my lesson-learned here is to avoid bikes with bottom-tier 12-speed drivetrains. The SRAM SX derailleur & shifter I removed look pristine. I guess the manufacturing tolerances just weren't up-to-snuff for 12-speed shifting. It does have a lot of plastic in it.

whatshubdoc

Go GX. I have a set for sale if interested. Also have XO1 set.

ARider2

I find the performance of the SRAM Eagle 12 SX to be unacceptable and I don’t blame the OP from going the Shimano route. I have a bike with the drivetrain and I haven’t liked it’s performance since it was new. I will eventually do a Shimano swap as well.

alexdi

The problem with SX is bushing wear in the fixing bolt. If you can rock the derailleur laterally when the bolt is tight, you have this problem, and 12S is intolerant of it. NX and GX have a better (but still inferior) fixing bolt design, and X01 and above are fine. I'm not aware of any problems with Shimano's M5100 and up and would choose any of them over SRAM derailleurs below X01 if you can get on with the shifter.

If you're getting consistent shifting on only half the cassette, I would verify:

* The derailleur doesn't rock
* The B-screw is set correctly
* The cassette is tightly mounted and not excessively worn
* The freehub spins true
* The hanger is tight and true
* The wheel is correctly seated and fastened in the dropouts
* The cable routing correctly follows the plastic cable guide channels under the BB (if present) and the derailleur
* The cable is clamped in the intended location
* The barrel adjuster on the shifter is not dislodged
* The chain is a 12S model sized correctly for the bike

If that's all fine, the problem is probably the shift housing. It could be excessive friction at the ferrules, a poorly cut or poorly seated housing end, or flex in plastic components if the bike is internally routed with a split housing. You might experiment with a new full-length run and cable.

J_Chickles

yes -like the OP did i want to also swap sram shifter and derailleuer for shimano - probably xt - soon. its better grade X01 stuff but still not butter smooth like shimano.

carlosponti

I have the NX and its fine for me. I do know the SX has a completely plastic body for the mechanical parts and flexes under load. Its a terrible shifter no matter what brand anyone prefers.