Chainset question

[Augustus]

Will there be issues of chainline/ contact if I put a road compact 34/50 modern sram chainset on my 02 MTB with 9spd XTR.


Not worried about the 10spd / 9 spd issues, already running those and that's fine, more concerned that road chainsets are different and chainline/ bb will somehow not work on my mtb frame. ?

Opinions?

 

[tintin40]

I would say yes would be issues.
But what do i know :roll: I have an out dated view of life, world, manners and politics in general.

 

[MikeD]

Road double chainline is 43.5mm compared to 50mm for MTB (if it's modern/outboard bearing stuff - might be 47.5mm for something older). So the rings will be further inboard (as well as the outer being bigger) and there's a good chance that at least one of them will hit the chainstay. How much chainring clearance is there with an MTB triple on?

 

[Marmite King]

Not sure about this one, but being an engineer I would say to try it then see where the problems are.........if any, then look for a solution.

You may need to change/modify the BB to alter the chainline ( different axle length on the drive side )

 

[Augustus]

How much chainring clearance is there with an MTB triple on?

not much.

02 merlin M952 chainset. (46t not 48t).

hmm can't try it and see as it's not bought yet. has to be proven hypothetically first. :roll:

 

[barry2017]

You can sort the chainline easily enough, just a different length axle.

Problem will be with the front mech and indexing. The indexing is slightly different, and the shape of the front mech's cage is different, 'cause road rings are bigger.

Although I see Shimano R440 road thumbies are £15 in the CRC sale.

 

[cchris2lou]

you ll have issues with the cranks touching the frame .

I doubt you will find a long axle for a modern chainset .

 

[Augustus]

You can sort the chainline easily enough, just a different length axle.

Problem will be with the front mech and indexing. The indexing is slightly different, and the shape of the front mech's cage is different, 'cause road rings are bigger.

Although I see Shimano R440 road thumbies are £15 in the CRC sale.

modern extrenal bb set up. axel is fixed.

Think i may walk away from this impending headache and just tippex SRAM on the back of my cranks to get the desired effect....(such a tart).


:cry:

 

[barry2017]

Oh yes, didn't read the 2009 XTR bit.

 

[Augustus]

Oh yes, didn't read the 2009 XTR bit.

nah, the xtr is old, it's the sram bit that would be new. quite liked the idea of a light double that had SRAM written on the back of the crank.

Would have a Middleburn Duo, but the rings are too small. Like the idea of a 34/50. Works really well off road on the cx bike and then on road on the way home too.