Have accidently ordered a road bottom bracket instead of a MTB one, is there any major differences? Mostly… will I die if I put it on my MTB or am I better and safer swapping it for a MTB one? It’s a hope bottom bracket if that makes any difference. Cheers!!

I think the tube length may be different but the BB and bearing will be identical – Well I can see no reason why they would not be but I am not certain.

Well, the Hope “road” seems to be Italian threaded (according to Wiggle, at least http://www.wiggle.com/hope-stainless-steel-bottom-bracket/ ), so it most likely won’t fit.

I think with the hope, it’s just the centre tube and possibly a lack of spacers. Have a look at the hope tech page for the exploded diagrams and compare part numbers.

The Merlin page says it’s an English thread: https://www.merlincycles.com/hope-stainless-steel-road-bottom-bracket-53954.html

Yes, and the pdf on their website also says BSA – the 68mm Road and MTB BBs differ by overall length (which implies tube is different): http://www.hopetech.com/wp-content/uploads/2014/03/BB-Selection-Table_Iss-5_09-2015.pdf

The description on Wiggle doesn’t apply to Hopes, it’s a generic one and should be ignored :).

Same part numbers for cups, bearings and shields. Just sleeve and spacers that are different.

Have a spare sleeve and spacers so should be ok… Thanks for the help everyone!!

Shimano Road BB cups are 1mm wider than MTB. You can omit the spacer to get the correct width on 73mm BB, ultimately the chainline will be very slightly different.

I did successfully use a road BB on an MTB by re-using the middle tube and spacers as people have suggested. Was a Shimano, but the sizes are dictated by the crank set, so have at it.

External BB’s were an opportunity to improve BB performance! Sadly it’s been exploited as a back sky rocket (thank you very much) endeavour and we get shack manufactured BB’s made of spit and feathers, that wear out on the non-drive side very quickly!

Has anyone tried the new shimano bb’s? Went to order an xtr from rose only to see they are no longer £9 and the xtr and xt are now black and have even smaller bearings and come with an adapter so you can use an old style ht2 bb tool

the new Shimano road BBs are indeed smaller and lighter but I’ve not had much luck with mine. I’ve been through two in not many miles so may go back to the older, heavier version next time around. As you say, smaller bearings so quicker to wear – the old ISIS issue.

Saying they are as bad as ISIS is quite extreme 😉