SLX 172.5 compatible crank?

[MudLark]

Hi guys,

Some years ago I converted a Procaliber into a monster cross bike. Because it was the only frame I could find at the time, it is XL whereas I normally fit on an L. But I managed to make it work. It is an older set up with 2 x 10 SLX. The crank is 175, which is a bit long for me. I would much prefer 172.5. Is there any compatible crank I can look for that will fit, using the existing chainring etc?

 

[droo]

You'll get a 170, not 172.5. 2.5mm increments are for roadies.

[DieselnDust]

Only the XTR cranks came in the 

167,5

172,5

177,5

kength options.

with newer franks Shimano has only kept the 167,5 for XTR with all others only in 165, 170 and 175 options.

you can try to find a cannondale hollowgram Si crank and acquire the appropriate length axle but this is 30mm vs Shimano 24mm axle.

praxis , garbaruk and a few other speciality crank manufacturers maybe have 172,5 in the options list but the chainring and bb will likely need to be replaced as Shimano uses proprietary chainring mounting templates 

[christovdw]

You can always go the Shimano GRX route. They’re readily available in 172.5. Csixx have GRX specific chainrings, but it will obviously be an extrs.

[MudLark]

21 hours ago, DieselnDust said:

Only the XTR cranks came in the 

167,5

172,5

177,5

kength options.

with newer franks Shimano has only kept the 167,5 for XTR with all others only in 165, 170 and 175 options.

you can try to find a cannondale hollowgram Si crank and acquire the appropriate length axle but this is 30mm vs Shimano 24mm axle.

praxis , garbaruk and a few other speciality crank manufacturers maybe have 172,5 in the options list but the chainring and bb will likely need to be replaced as Shimano uses proprietary chainring mounting templates 

Thank you Diesel.

[DieselnDust]

17 hours ago, christovdw said:

You can always go the Shimano GRX route. They’re readily available in 172.5. Csixx have GRX specific chainrings, but it will obviously be an extrs.

Chainline is 49.7mm for the FC-RX610-1 so this can work if the frame can accept a 38T to 40T chainring and 151mm Q-factor. Chainstay outside width at various points vs the crankarm width is important to know to prevent the arms hitting the stays.

 

Edited June 7, 2025 by DieselnDust