I’ve just put an absolute black cassette extender block on and its been a nightmare. Shifting is lazy at best and the margin for the b tension is ridiculous. You have it so that it clears the cassette and mech doesn’t rub and the shifting is just too god damn lazy. Slacken the b tension off and obviously the mech rubs. Its a brand new chain and its only a 40t. The chainline is mentally out as well. I know that these things are a compromise but i reckon i night have to wait until the lot wears out and try an 11speed sram set. I love the simplicity a 1x system offers but this seems a bridge too far……

My experience of cassette extenders is that those who buy them are either fat, lazy, unfit or any combination of the three.. 😉

hope t rex (i think) 40 tooth on my sram cassette with x9 mech. Needed a touch more b screw, didnt need the supplied longer one, shifting is absolutely perfect.

Great 2nd answer there 🙄

The new One-up mech cage fixes it, as does running an SRAM mech which already has same offset jockey wheel set-up as the One-up cage. Otherwise, yes, the shifting is poor on a Shimano system.

Edit: to clarify, I’ve got one on both my bikes, a 40t Hope on the hardtail with a Shimano transmission and a 42t wolf tooth on the big bike with an SRAM transmission. The SRAM set-up always worked spot on, indistinguishable shifting from a standard set-up, the Shimano set was very lazy shifting until I fitted one of the One-up cages to the mech, and the shifting is now spot on again.

Right, I’d read after I’d bought the part that shifting is affected. Not sure its worth the hassle and further expense

I’d suggest that if you have a mid cage mech, the extra £25 for a new cage that fixes the shifting is worth it, I’m happy with my top gear as is and no longer see any need to think about SRAM 1×11 until everything wears out and dies.

Its a zee fr mech that’s on

I’ve sacked off trying to run a zee with an extender

It didn’t help having a bent mech hanger but I’m not convinced by the reliability of the mech and jockey wheels. Had two warranty replacements from crc

XT medium cage now and everything works fine

Full SRAM setup with Hope, worked without even touching the B tension. Moved one spacer on the BB to tweak the chainline a little. No real drame just a lot of simplicity.

I bought a T-Rex to use with a Zee FR mech, appeared to be terrible to set up and in the end I’ve given up and took it to a local bike shop. If it’s not any good Ill just have to get a replacement hanger if it’s going to make the difference.

It was great, then I reduced the pressure on my shock a little for more sag. Now it’s very noisey so I’m going to have a play with the b tension tonight. If that doesn’t fix it I’m concerned the chain may be too short .

Running two T-Rex’s. The full suss is using a medium cage XT mech and the hard tail a Sram X9 Type 2. No shifting issues with either of them.

I went back to a triple. Got fed up with spinning out down hill and stalling in boggy conditions.
Sure it weighs a bit more but my commute record was broken by 3 minutes.

My RW still going strong.

I went back to a triple. Got fed up with spinning out down hill and stalling in boggy conditions.
Sure it weighs a bit more but my commute record was broken by 3 minutes.

I suppose if your ‘descents’ are fire roads, and you spec your mountain bike for commuting, then triples are a fine choice. 😀

One up rad cage and 42t expander here. Works flawlessly (once I’d got the cage spring in the right hole)
I’ve had x01 before and this works better to my mind. And it’s not SRAM which is a huge bonus.
I use an xtr mid cage mech, the zee simply doesn’t have the capacity to cope with the gear range you are trying to achieve. Also,how on earth is you chainline out? Unless youve spaced the chainring or put the adapter on wrong then the chainline won’t have changed!

Dave thanks for the exclamation mark, rode the 40t for 10 miles or so and wear is apparent on the chainring that wasn’t there before, either way the shifting quality loss is not worth this extra hassle. I’ll just have to get fitter