SLX M7100 spindle too short?

Bear with me as I’ve not used Hollowtech components for nearly 10yrs, but current bike build is with a SLX group, so have now gathered numerous new tools (another story).

So, cranks are in place, one spacer on drive side. LH crankarm sits happily on the spindle. RH crankarm is a lot closer to the chain stay than the LH crankarm. So much so that the crankarm boot catches.

Tried with two spacers but the LH crankarm has less to grip. Doesn’t seem right. Cranks are M7100 for 52mm chain line, frame is a NP Mega also 52mm chain line.

Are there different spindle lengths for M7100? Bought as a SLX 12sp bundle from Cotic.

Time for a brew

Ta, Hoj

Is the BB shell 73mm ?

Check the part number of the drive side crank.

Is it a new frame? Last time I had something like that it was the frame that was out of whack

There are quite a few different models… https://bike.shimano.com/en-EU/product/component/slx-m7100.html but I’d say the ‘standard’ is the FC-M7100-1 , that’s what I’ve got. The FC-M7120-1 looks like it might be better for you – but I’d be blaming the frame here, I can’t see any special notes on here https://nukeproof.com/products/07e7-mega-290-alloy

Shimano sell their cranksets in 3 variations of chainline, and each one has a different Q factor.

172mm Q factor 52mm chainline M7100

178mm Q factor 55mm chainline M7120

181mm Q factor 56.5mm chainline M7130

You probably need a M7130 for your bike.  It seems even on the Shimano Megas, nukeproof never speced a Shimano crankset.

My Canyon spectral came with a M7120 – with a 73mm bottom bracket shell and 2 24mm spacers on the crank axle

It seems even on the Shimano Megas, nukeproof never speced a Shimano crankset.

“Shimano Deore M6100 12 Speed Crank, 175mm, 32T, 52mm Chainline” was specced on the Comp a few years ago. Just to further muddy the waters.

Odd that it was then dropped for future specs, so wonder if it was a mistake to spec that one

My tuppence worth ( for what its worth) is that the frame or more specifically the rear triangle may be the culprit. Presuming 73mm BB shell the NDS looks good clearance wise – presumably better (by the width of a spacer) when using just one DS spacer as should be the case* with a 73mm shell and Shimano.

Does the chainring catch on the chain stay with just a single spacer (let alone the crank arm)?

A 55mm chain line crankset may work “better” presuming (again) that not just the chainring moves over.

Was the frame from Chiggle?

*there are always exceptions 🙂

Thanks for getting back to me folks, shell is 73mm and both crankarms are M7100.

As far as I could find, NP used to spec m6100/ 52mm chain line on their base spec 290, so not quite sure why this is wronk.

No worries, sounds like I may need a different chainset, which is annoying.

Ta

I had a similar issue on a road bike, the frame was out, it was replaced

Yes it’s a Chiggle special,  no, there is zero chance of frame replacement so I’ll have to make it work!

put a long straight edge on the chainring, is it parallel to the down tube? It might be the angles the pic is taken at but the BB shell doesn’t look perpendicular to the frame to me.

Well ? Have you sawn it in half and binned it yet?