GRX rear mech compatibility with road shifters.

[Barry and Janet wil]

On my tandem I'm wanting a lower bottom gear and I also want to change to 11 speed, yes the wheels are 11 speed compatible.

An 11-36 or 11-40 cassette seems ideal and I'd operate it as 2x11. I believe that the GRX rear mech will be needed but which road style RH shifter, which also works with cabled rim brakes, will I need? I'd use the GRX shifter but I think it's only available in hydraulic.

I'm a trendy consumer. Just look at my SM-G950F using hovercraft full of eels.

[PT1029]

What sort of rim brakes have you got? Without knowing this, it is impossible to suggest a correct lever (cable pull and all that).
If dual pivot or similar, approx age can be important, as "105" (or what ever other you might have) might have differing cable pull requirements depending on vintage.

[ChrisF]

There's a useful article on this subject here https://road.cc/content/feature/how-get ... res-246424 - initially about gravel bikes but the suggestions would be OK for a tourer or tandem.

[Jamesh]

I'd think you would want 11 SPD 5700 105 levers or ultegra Dura ace.

Cheers James

[Redvee]

I'd think you would want 11 SPD 5700 105 levers or ultegra Dura ace.

Cheers James

5800s are 11 speed, 5700s are 10 speed.

[pwa]

The GRX rear mech for double chain rings is only rated up to 34t, which with Shimano means you might get away with a bigger sprocket but it isn't meant to do that. The single chain ring mech is rated up to 42t, but will it work with double chain rings? There must be a reason it is marketed just for single chain ring use.

[Jamesh]

Sorry 5800 shifters.


Cheers James

[slowster]

The compatibility of the shifters with the derailleurs is moot if there are no suitable rim caliper brakes for the levers. I would be willing to try mis-matched levers and calipers on a solo, but not on a tandem.

[Richard of York]

My 105 RD works 12-40 11spd cassette with a rear mech extender. It's with 50/34 chainset.
https://www.spacycxles.co.uk/m8b0s222p3 ... ender-Link

[Barry and Janet wil]

Wow, you guys have moved this thread on a fair bit.
At present I use 5700 shifters and they work really well with XT Vee brakes up front and a rear disc brake.

Maybe thinking about grx is a bad move, really I'm open to any modern 11 speed solution that will cope with a 36 or 40T cassette. And also it would work with my brakes but I'd consider a (I think its called) traveller.

I'm a trendy consumer. Just look at my SM-G950F using hovercraft full of eels.

[Barry and Janet wil]

The GRX rear mech for double chain rings is only rated up to 34t, which with Shimano means you might get away with a bigger sprocket but it isn't meant to do that. The single chain ring mech is rated up to 42t, but will it work with double chain rings? There must be a reason it is marketed just for single chain ring use.

I imagine it's based on the amount of slack chain it can take up. If we include 16T of slack due to the front derailer then less would be available to accommodate the rear slack. Though why 2 models, I dont know.

I'm a trendy consumer. Just look at my SM-G950F using hovercraft full of eels.

[PT1029]

I'd consider a (I think its called) traveller.

Almost. I think you mean travel agent (not of the ABTA variety), allows the use of V brake/ATB disc brakes with non V brake levers
https://www.sjscycles.co.uk/cables/trav ... lack-each/
https://problemsolversbike.com/products ... nts_-_6416

"Travellers" I recall being made by Morris Motors!

[Barry and Janet wil]

"Travellers" I recall being made by Morris Motors![/quote]

yes I remember them.

I'm a trendy consumer. Just look at my SM-G950F using hovercraft full of eels.

[Dirk]

The GRX rear mech for double chain rings is only rated up to 34t, which with Shimano means you might get away with a bigger sprocket but it isn't meant to do that. The single chain ring mech is rated up to 42t, but will it work with double chain rings? There must be a reason it is marketed just for single chain ring use.

FWIW, I run a 10 speed RX400 rear derailleur, a 46/30 chainset and an 11-36 cassette on one of my bikes. It works well with no problems. On another bike, I have an R7000 rear, a 46/34 chainset and a 11-40 cassette, again it works well.

[Barry and Janet wil]

Hi Dirk. Is the R7000 rear mech a long cage one?

I'm a trendy consumer. Just look at my SM-G950F using hovercraft full of eels.