Bottom bracket spindle length

[Richardcs]

Hi... Hoping for some advice... I've just picked up an old orange p7 nickle.. I got a deore lx crankset with it, but no bottom bracket. I know it's a68mm shell, but how on earth do i work out what spindle length I need? Thanks for any advice

 

[Richardcs]

Re:

Think I've posted in the wrong section!!!

 

[FluffyChicken]

Re:

I think you have, but unfortunately also "LX" does not help.
either read the M5xx number of the back of the arms or take some pictures or both
There are various LX models.
they're probably FC-M563 and will use a 107mm bottom bracket for perfection, you could use a 113 if you don't mind the slightly wider chainline.