Calling the skills of some serious bike geeks!

Trying to replace the BB on my m951 cranks (here old skool rules IMO) single ring set-up.

Think I’ve got a 73mm shell with a 116 axle but yet to take out and confirm.

From a bit of digging I see this is V1 where 105 and dura-ace units fit.

Would this be wise fitting say a 105 at £25.. assume correct fit as V1, be strong enough (12st and from a bmx/dh background) and fit as axle is a 118 (1mm differnt chainline)?

Or should I just stump the cash up for one from Merlin at £55?
merlin m952 bb

Got hollowtech 2 external bearing cranks on another bike but there’s something about these that is just sweet..

I use M950s on my SS with a 105 or Ultegra BB. They fit fine and last forever. As a point of note though, if you mention your DH/BMX-ness as a subtext for mashing parts, the ‘proper’ M95x BB has deeper splines so you will have a stronger contact between the components. You pays your money…

Thanks mtbfix had an inkling that the 105 bb had a slightly different spline despite both being v1.

Wonder how the axle strength compares too.

Purely mentioning the bmx/dh background as use the bike for more than just xc and can give the bike a bit of a mauling sometimes.

think I’ll cough up the extra for the xtr bb for the piece of mind knowing 100% spline fit and mtb/dh axle strength. Plus these units last years, my current has been on the bike for atleast 5 years and gets used daily to commute and generally thrashed.

Sounds like a good call buying the XTR BB.

For the record you can measure both the BB shell and axle width without removing the BB, as long as the cranks are off. A good set of vernier calipers is all you need.

The spline is the same, but the length is different, xtr is 112.5 & 116, the road ones are 109 & 118. For ss it would probably be fine, but I can remember a mate who fitted a 118 and could get the outer ring properly.