Crankset and BB problems

[fullerlee]

Hi
I've had my Kona Caldera powder coated and I'm assembling for the first time but I'm stuck.

I have a hollowtech BB which I have fitted ok. I have a Shimano M751 crankset, but without axle.

I also have a Bontrager 7050 crankset with axle, but it doesn't look compatible with the Shimano. I'd prefer to use the Shimano.

Can anybody point me towards a compatible axle please?

Thanks.

 

[legrandefromage]

you are trying to mix external and sealed BB cranks

The XT is Octalink

The Bontrager is external and 'may' need a GXP bb

both are getting harder to find, especially the Octalink in the right length axle

Octalink 113mm length 68mm (sold out though)

https://www.amazon.co.uk/Shimano-ES70-O ... B000OQQ7CA

GXP but only your Bontrager cranks have 'GXP' written on them - otherwise they just need a standard shimano external BB

https://www.wiggle.co.uk/sram-gxp-team- ... lsrc=aw.ds

 

[fullerlee]

Re:

Thanks! This is a minefield, but fun

The Bontrager is indeed GXP, so I'll have a look for the types that you mention.

 

[ishaw]

Re:

You can get bbs that will work with both ht2 and gxp standards. Gxp needs an adapter on one side to work with an ht2 bb. You can buy adapters but it is marginally more cost effective to buy a bb that comes with one. Try searching on ebay for ztto ones. They are decent quality and can be had pretty cheaply.

As mentioned, the original hollowtech bbs (essentially the axle and bearings for your xt cranks) are getting harder to come by.

 

[fullerlee]

Re: Re:

Great, thanks for the detailed answer. Looks like about £20 from China or £30 from UK.

You can get bbs that will work with both ht2 and gxp standards. Gxp needs an adapter on one side to work with an ht2 bb. You can buy adapters but it is marginally more cost effective to buy a bb that comes with one. Try searching on ebay for ztto ones. They are decent quality and can be had pretty cheaply.

As mentioned, the original hollowtech bbs (essentially the axle and bearings for your xt cranks) are getting harder to come by.

 

[ishaw]

Re:

Heres one with ceramic bearings for not much:

https://www.ebay.co.uk/itm/174466880147

 

[Grumble99]

There are a few Octalink bottom brackets on ebay.