Background:
My old man is one of those guys who believed that if tight was good, tighter was better. As a result, I could use broken bolt extractors at an age when most other kids were learning the difference between flat-blade and Phillips head screwdrivers.
Situation:
While I've become quite smitten with the Motobecane, there has been a hitch in the drivetrain on the drive side when you hammer on it or grind up hills. I figured it was a not-quite tight enough crank bolt, and snugged it down. No joy.
I then pulled the cranks and discovered that the spindle had been greased. I cleaned it up and re-installed the cranks. Worked for about 5 miles, then the hitch was back.
Pulled the cranks again, mounted them 90 degrees from where they had been, and torqued the crank bolts to 30 ft/lbs. Still no good.
In times of stress you revert to your earliest training. I dug through my parts, found a couple of crank bolt washers, installed them between the crank and the bolts, and wound on. Got to 30 ft/lbs and kept going. At 40 ft/lbs I though 'just one more little pull and.....SNAP!'





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sucks...

What are the specs on that spindle? Need a replacement?

-Kurt

Look at it this way, better it broke on the bench than say, climbing a hill!

BTW, it looks like you just pulled the threads from the nut. The spindle threads may clean up, though that still won't solve your loose crank problem.

"it looks like you just pulled the threads from the nut." QUOTE.


I too thought, that but it appears upon a closer examination that the

nut has "pulled off", the external axel thread; this being rather odd in that

the nut loads from it's "start". The nut was hardly engaged when this

happened by the looks of the situation - high loading upon first few threads!

Could the washer(s) have caused this? More than likely.


Regards,
J T

of course, the very picture of the reason why crank bolts are better than crank nuts.

Yeah you're probably right, the diameter does look a bit smaller on that end now. Too much torque on too few threads.

Kurt. thanks for the offer.
Now the good news-the spindle is a 3 S-common as dirt. The first three spindles I pulled out of the bag matched. And while changing out the spindle I found that the fixed cup was only finger tight. With the new spindle and the BB cups tight the problem seems to be solved.
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