Blinkin ISIS drive cranks don't fit my ISIS BB gggrrrrr!

[MontyVeda]

You think you're replacing like for like but why the feck are the splines on my new ISIS drive cranks a heck of a lot smaller than the splines on my old ISIS drive cranks???

 

[MichaelW2]

ISIS or Powerspline?

 

[jefmcg]

 

[MontyVeda]

ISIS or Powerspline?

the spec sheet for the new crankset (Left in the pic) says ISIS interface. My old crankset (on the right) has ISIS printed on the crank arm... but they're completely different sizes!

Edit... but turning the new crank over, i've noticed that it's got powerspline stamped on it. GRRRR!

 

[Lonestar]

Can't you put the new teeth on the old crank?

Probably wouldn't fix it fully?

 

[Poacher]

Serves you right for not using square taper!

 

[MontyVeda]

Can't you put the new teeth on the old crank?

Probably wouldn't fix it fully?

splines on the old crank are worn... so it's loose even when tight.

 

[MontyVeda]

Serves you right for not using square taper!

agreed... but aren't there two types of square taper these days?

 

[Poacher]

agreed... but aren't there two types of square taper these days?

Indeed there are, and have been for, well, decades: ISO and JIS. As always, Sheldon explains this well. Although there are two types, you can sometimes get away with mixing them; my Spa tourer has a Campag racing triple on a Shimano BB. Creaks a bit, though!