Compatibility issues when converting from 32t chainwheel to a 38t
 

Hey!


Recently upgraded my 3x8 beloved 20 year old aluminium hardtail to a 1x10, and now have a 50 mm chainline, with this setup:


Crank: Shimano Deore FC-M5100-1

Chain: Shimano CN-HG54

Cassette: Shimano Deore CS-M4100 (46)

BB: Shimano SM-BB52

Derailleur:Shimano Deore RD-M5120-SGS

Shifter: Shimano Deore SL-M4100


I miss the power of 3.23 & 3.82 ratio I had on the 3x and thought an upgrade to a 38 t would be great for a 3.45 ratio. (I hardly use the lowest gear anyway)


I'd appreciate a chainwheel recommendation that will fit the chain and crank I have.

Will the old bolts fit? or do I need to replace the as well?


Regards,

Ran

Last first. Chainring bolts are among the most standardized bike parts, so no issue there.

Rings with the same mount, ie. 5 bolt, and bolt circle will fit. There is some variance in offset, but not enough to fret over on a 1x system.

The only fly in your ointment MAY be whether the FD can be raised enough, or clear the curvature at the back. But you can deal with that IF it's an issue.

your chainring is an assymetric 4 bolt pattern, at 96mm BCD`...The Derailleur you listed will work with the 46 tooth cassette you listed, according to Shimano's specs, as will the HG-54 chain....I'll assume you mean a 38 Tooth Chainring... Remember that it's an ASSYMETRIC Bolt pattern. Here's a link that shows the odd bolt pattern's specs... https://www.ebay.com/itm/22351845440...3ABFBMkLK4_Nlh

So maybe you don't need a 11-46T cassette then?))