SRAM and Shimano

[Danny521]

Hi I’ve got 2 bikes one with sram wireless shifter and one with cable shimano gears both bikes are 12 speed I’m wondering with out getting my self new wheels as one is 27.5 and one is 29 so can’t swap over would the seam wireless shifter work on the shimano cassette and shimano chain and then the other way round would shimano gears work on a sram cassette and sram chain as they both 12 speed sorry if it sounds dum just looking for advice before I mess around just wonder if anyone as done the same thank you

 

[nickf]

It's not a dumb question. In mechanical systems the indexing (ie by how much the cable is pulled) is done at the shifter. The derailleur design then has a "leverage ratio" which determines by how much the derailleur arm will move laterally for a given cable pull. The amount of lateral movement needs to correspond precisely to the lateral spacing between the rings on the cassette, Naturally Shimano and Sram choose to use different ratios at both the shifter and derailleur! So you can't just mix and match between shifters and derailleurs from the two brands.

However, what's key here is that (whatever the brand of shifter/derailleur) the derailleur arm moves laterally just the right amount for the cassette. You could try putting the 27.5 wheel on the 29er bike and seeing if the derailleur movement works across the whole cassette. If so, then it should also be OK with the other configuration. However, you will probably need to reset the end stops of the derailleur to match the cassette when you swap.

I don't have experience with electronic shifters, so others here might be able to confirm or refute what I've just said, but the principles are the same.

 

[Danny521]

It's not a dumb question. In mechanical systems the indexing (ie by how much the cable is pulled) is done at the shifter. The derailleur design then has a "leverage ratio" which determines by how much the derailleur arm will move laterally for a given cable pull. The amount of lateral movement needs to correspond precisely to the lateral spacing between the rings on the cassette, Naturally Shimano and Sram choose to use different ratios at both the shifter and derailleur! So you can't just mix and match between shifters and derailleurs from the two brands.

However, what's key here is that (whatever the brand of shifter/derailleur) the derailleur arm moves laterally just the right amount for the cassette. You could try putting the 27.5 wheel on the 29er bike and seeing if the derailleur movement works across the whole cassette. If so, then it should also be OK with the other configuration. However, you will probably need to reset the end stops of the derailleur to match the cassette when you swap.

I don't have experience with electronic shifters, so others here might be able to confirm or refute what I've just said, but the principles are the same.

I’m not sure if the 27.5 fits on the 29 one but I’ll take a look at that I suppose if it does that’s one way to tell the the sram wireless shifter will work on the shimano cassette

 

[nickf]

I’m not sure if the 27.5 fits on the 29 one but I’ll take a look at that

Why wouldn't it fit?

 

[Danny521]

Why wouldn't it fit?

Because it’s not made for 27.5 but then again even if it not (I know some have a flip so u can put a 27.5 on rear) it’s not like I’m fully riding it I’m just checking if the sram wireless shifter will work on the shimano cassette

 

[Stihldog]

At the time, when I first read about the Shimano/Sram AXS hack, it was considered the best of both worlds. I’ve been using this combination for several years now.
-29’ wheels
-Shimano XT 12 speed cassette
-SRAM AXS derailer with paddle controller
-Shimano 8100 chain
- Shimano 13 tooth guide wheel
-E-Thirteen 34t chainring

This is on my Rail 9.7. Smooth, quiet and fairly fast.

On my Fuel EXE I use an AXS SRAM transmission only. But I have spare wheels with different rubber for trail or pavement. This allows for a quick change without removing the tire each time.

I don’t use 27.5” wheels on either bike.

 

[Danny521]

At the time, when I first read about the Shimano/Sram AXS hack, it was considered the best of both worlds. I’ve been using this combination for several years now.
-29’ wheels
-Shimano XT 12 speed cassette
-SRAM AXS derailer with paddle controller
-Shimano 8100 chain
- Shimano 13 tooth guide wheel
-E-Thirteen 34t chainring

This is on my Rail 9.7. Smooth, quiet and fairly fast.

On my Fuel EXE I use an AXS SRAM transmission only. But I have spare wheels with different rubber for trail or pavement. This allows for a quick change without removing the tire each time.

I don’t use 27.5” wheels on either bike.

This is what I’m wondering I’ve got a trek top fuel 8 gx with the sram wireless gears but I’ve just got a trek rail + 5 with shimano gears but wanting the sram wireless on the trek rail + 5 instead of the shimano gears but save me replacing the back wheel I’m trying to work out if I can just swap the gears over on each bike as they both 12 speed sorry move the sram wireless and sram derailer over to work on the shimano cassette and then other way round the shimano shifter and derailer on to the sram cassette

Sorry if the wording is not the best I try and word best I can

 

[Stihldog]

This is what I’m wondering I’ve got a trek top fuel 8 gx with the sram wireless gears but I’ve just got a trek rail + 5 with shimano gears but wanting the sram wireless on the trek rail + 5 instead of the shimano gears but save me replacing the back wheel I’m trying to work out if I can just swap the gears over on each bike as they both 12 speed sorry move the sram wireless and sram derailer over to work on the shimano cassette and then other way round the shimano shifter and derailer on to the sram cassette

Sorry if the wording is not the best I try and word best I can

Yeah, we’re probably both complicating the description to suit our personal needs.
This is what I’ve heard, or know. SRAM and Shimano 12 speed cassette’s are basically the same diameter. However, the freewheels can be different. And the cog numbers can be different.
There also might be the matter of chain alignment to the chainring. Some different thickness “O” rings(spacers) may be required for the cassette or chaining.

The different combinations could be endless. Seems like a trial and error mission until you get things just right for your personal needs.

In the end, I stayed with what works for me. I have spare front and rear wheels for my Fuel EXE. That was cheaper than an entire new bike. And the change is fast and easy.

Post your results if you have any success. (Inquiring minds want to know)

Edit; maybe ask Greg Watts. He may have some in-depth suggestions.