Are all square taper bb spindles the same tapers?

[Decan]

Just can't find any information on square taper BB spindle taper dimensions!
Bought a M737 chainset on ebay. Much to my disappointment the cranks slide onto my old square taper bottom bracket with no resistance. They slide right back to the shoulder at the top of the taper. To me the crank tapers appear to slightly big for the bb. :?
The old steel BB spindle works fine with my MT60 chainset I.e. The cranks slide snugly onto the spindle stopping 4 or 5 mill from the shoulder at the top of the taper.
The confusing part is that the tapers in both M737 cranks dont show any signs of damage and both have the exact same issue with the bb spindle.
Am I missing something ?
Are the tapers of all square taper spindles the same?
Can I get a 66x107 BB spindle with a marginally wider taper (+0.4mm) ?
Do M737 cranks normally slide up to the should at the top of the taper?

Confused!! No real info on the net!!
Heeeeeeelp ...

 

[sawston_vulcan]

check Sheldon Brown....ISO [Campag and njs] or JIS....that is a simplification.

But not all tapers are the same.

 

[Decan]

Re:

Thanks for the Info!
It was looking promising there for a moment.. As a read the references I thought that my shimano (JIS taper) crankset was having issues on a slightly more tapered ISO BB.
Unfortunately I believe that the BB is also JIS. The BB fits my Shimano MT60 crankset tightly. I've also tried the Shimano M737 crankset on a shimano BB UN 51 (JIS) spindle and the same problem exists. - it slides freely to the end of the taper with no resistance from the taper..

Is it likely that the tapers in the cranks have widened?
I'd solis there a solution?

 

[halaburt]

 

[one_bad_mofo]

Re:

Is it wrong to get excited by that picture?

 

[FluffyChicken]

Re:

Your crank tapers are knackered. Any pictures.

For this purpose they are the same, there are tolerances but the setup should take care of it.

If it was say raceface then they make there's slightly different to cater for a bit of grease. But its not that different and they tell you in their manual.

But for Shimano then they are the same.

Still M737 are designed for a 107mm axle, not a 122.5mm axle you will used with the MT60

 

[Decan]

Re:

Thanks for the great information, and the bad news

Pics attached. Are we sure they're knackered. Have even used them once after buying them !

 

[02gf74]

I can see scratches that seem to indicate they are used, so it is irrelevant that you have not used them as it seems someone else has.

Have you tried it on other bbs? Tis most strange.

 

[Decan]

Re:

There second hand all right. I meant to say that I haven't used them since I bought them used from ebay.

I've tried them on my old bb spindle and a very old and very well used BB UN-51 spindle. is there any chance that they might fit any tighter on a new spindle ?? Or a non-shimano spindle ??

 

[legrandefromage]

Axles dont wear out like that, they're all tool grade steel - your soft aluminium chainset tapers are knackered