i always thought that square tapers were all alike.

but then a couple of months ago i remember reading somewhere that theres square tapers and square tapers.

oh yeah by the way i'm talking about bottom bracket spindles.

if i have an old raleigh BB, will i be able to fit new, decent cranks?

and what's the deal with miche?

thanks a lot folks.

Search for JIS and ISO taper. Also old Raleigh BB's are different width to newer ones. How old is it?

http://www.londonfgss.com/discussion/2423/bottom-bracket-replacement-for-old-raleigh-3-speed-frame/

Sheldon has the details. As always.

cool, so what's the first step? measure the width of the spindle?

how can i tell if it's JIS or ISO?

How did you take that photo if the camera is behind the chainring?

mirrors.

mostly mirrors.

these cranks need to go, they flex so much.

Them and the pressed tin chainring!

i know, i know, hence original question.

everything is so expensive...

I was going to bring up the ISO vs JIS taper thing last week but then the
bottom bracket I was going to buy disappeared (roberto?). According to
Sheldon, they both have the same taper angle, but the ISO taper is a bit
longer, so that the ends are a bit narrower, but I don't know if it's enough
to be able to measure it reliably.

btw, in case roberto's dura ace 7610 bottom bracket somehow reappears on
the market, does anyone here know if it would have a JIS or ISO taper -
I was hoping it might fit some sugino 75s I have waiting to be fitted (on the
face of it the axle length is right).

Sadly not. Dura-ace is JIS - as is pretty much everything except for Campagnolo and the Sugino 75s. Although all other Suginos are JIS, for some reason, 75s are ISO

Bearing that in mind, a Campy bottom bracket would work for you, or preferably the Sugino 75 model or Phil Wood's ISO taper. The good thing about Phil BBs is that the cups can be replaced very cheaply, so you could move it from frame to frame relatively easily, rather than losing the (not inconsiderable) investment if you decide to get a new frame one day.

[quote] turpe:75s are ISO to meet NJS requirements.

I figured that might be it, but I couldn't be arsed to Google search to be sure.

It sort of works to remember that (mostly) JIS is Japan (Shimano etc)and ISO is Italian (Campag/Miche etc).

You can mix the two - I use a Shimano (JIS) BB on my MTB with a Campag chainset. Many do this without any problems - others claim it puts strain on the crank and can lead to fracture.

The tapers are different profiles though - an ISO crank on a JIS BB will go on a few mm's less.

A JIS crank on an ISO BB will go on a few mm's too far.

Best to keep like for like - to find out what you have pop the two together loosely by hand and it will be obvious whether it goes on too much/little/just right.

[quote] tynan:I was wondering if that might be the case - you see the shimano 7610 *is* NJS certified.

some older japanese ones - sugino cranks (mighty, not sure about super mighty) are ISO too. as are some old SR/Sakae ones.

any clues on miche?

i remember someone mentioned that the primato cranks only go with the primato BB?

summink to do with spindle width?

Miche are standard ISO. Any Campag BB etc will work, buy the length to suit your frame and chainline. Normally 111mm IIRC.

the miche cranks i have were on a shimano bb

you can basicaly mix iso taper with jis cranks and vice versa....only if you have ISO cranks the chainline would be slightly different on JIS axle and on ISO axle......the mixing of tapers was basicaly more of an issue back in the days where you had to take off the cranks more often too clean and adjust and grease the loose bearings BBs.......and by constantly tightening the crankbolts every now and then you were widening the square on the crank........it happens on JIS vs JIS also but on lower scale then on ISO vs JIS or vice versa..........so there.......as long as you keep the cranks screwed on tight and not TOO tight there shouldnt be a problem........