that old miche iso/jis bb question.

Slightly confused as to which BB i actually need to fit this crank. Most the conversations/threads ive read havent helped because theres several different miche primato chainsets. looking for bsa 68x107. Wiggle list the primato BB at just £12.59 but reading the reviews it sounds like theyre sending out two different versions at random and some people receive the flanged one whilst others get the adjustable and i could get on the phone to them but i dont know which variant i need. Current BBs i have sitting around at home (a neco and a shimano un72) arent right, the crank arms dont slide on enough. LBS was like "?". Anyway cheers for your suggestions and if anyones got a BB sitting around thatll do the job let me know.

If the crank doesn't slide far enough onto the jis taper of the un72 I'd say that's pretty clear indication you need an iso taper bb.

Miche don't seem to take much heed of taper spec and supposedly changed the Primatos from iso to jis overnight and without really informing anyone so I'd sack their bbs and go for one from a more reliable brand.

FWIW I've ran supposedly iso Primatos on Shimano bbs without issue.

I believe miche cranks with the new primato logo (pictured below) use a JIS taper and need the newer, flanged JIS bb.

Older cranksets with the PR1MATO logo (like the one you've posted) are ISO and need the adjustable ISO bb.

I've got a Chorus 111mm ISO BB for sale if that's any good...

cheers for the comments guys, ive just picked an iso miche one up from one of the classifieds on here. Coupled with realising I do have other narrower and wider iso bbs here on various bikes I have I think im sorted.

I had the same cranks as those pictured above on my pompino. I ran it initially with a 107mm primato bb (which is ISO) then when it started to get rough (as they often do) I replaced it with a 111mm shimano on (a un55 if I remember rightly) JIS bbs have a slightly narrower taper than ISO ones so by getting the slightly wider bb in the JIS spindle, this meant my chainline stayed good as the cranks slide further onto the narrower spindle. I hope this makes sense!

What I've just said is wrong! I replaced the Miche bb with a 103mm shimano one! ISO cranks on a JIS BB sit further frame from the frame by about 4mm.