Stevan, I unfortunately do not have possession of the camera I do "time shares" with just at this moment. I will forward pics just as soon as it's my turn to use the camera. However, according to your method, the cranks are closer to 151s. The actual measurement came out to about 11mm, and not 10. I neglected to mention that the shoulder on the drive side arm has been ground down. What are the possible reasons that a crank arm would be modified like this? Newer bottom bracket? My continued thanks to you and the other reading, contemplating, and/or responding list members...
Best regards, Mark Agree Detroit MI
Stevan Thomas wrote: Can you send a picture? You may have an old variation that tends to break, and if so, you may want to move them to the shelf. The rings are for half step gearing, I suspect a 151 bolt circle? Measure from the center of the ring bolt to the edge of the ring. It's either 7mm or 10mm. 10mm means 151.