Originally Posted by
HillRider
Any chance you are trying to use an ISO bottom bracket with JIS cranks? The ISO crank could slide too far up an ISO taper and the end of square taper bottoms out the nut before the torque is adequate.
How would one distinguish between the two different square tapers?
Sheldon's site implies I might find JIS tapers would measure shorter but he left no quantitative data:
http://www.sheldonbrown.com/bbtaper.html
I've looked at the brand list on Sheldon's site, there is a strong chance both bikes had JIS cranks originally.
The bike that went through several cranks was a Raleigh Technium 440 from the late 80s.
The bike currently exhibiting it's first crank retention failure is a 77 Raleigh Super Grand Prix.