Crank Seizes Halfway Thru Removal

During removal of a self-extracting crank arm and cap (Kris Holm/Onza Splined Hub and Crank) the torque required on the crank bolt went from normal to a bit harder and then quite abruptly it locked up. Significant torque resulted only in a couple brief turns with accompanying over torquing “crack” noise. In attempting to reinstall the crank the same over torquing noise occurred only slight rotation of the bolt was achieved. Henceforth I have been unable to either further remove or further reinstall the crank.

While I am interested if there is a simple solution, I fear the my beginning to strip the hex bolt socket means that the bolt would have to be drilled out or some other heavy cutting done.

Therefore I am most interested in an explanation of why the crank removal started easily enough and then seized up.

The retaining ring for the bolt is threaded backwards on that crank arm. As a result it will tighten as the bolt is unscrewed from the axle. I suspect that this is what is hapening, and that if you use a pin wrench to loosen the retaining ring (loosen by turning it clockwise) the bolt will again turn freely.

It should be very easy to remove those cranks. I had a set on my last MUni that I didn’t use the self extracting hardware on. I just took the bolts out and pulled the cranks off. They aren’t a press fit, they just engage the splines along a straight axle with no taper. I think the attachment is called a “slip fit” but I’m not exactly sure.

I had the same thing happen with one of my KH self-extracting cranks; it got totally jammed. It was then quite challenging to get the self-extracting bolt off; in fact I think I wound up drilling it out.

From then on, I’ve just ignored the self-extractor and used a standard crank tool to take the cranks off.

A standard crank extractor won’t work on a KH/Onza crankset due to the reverse threaded extractor threads. I think that they only figured it to be used with the self extractor hardware. The thing is that an extractor isn’t really necessary for those cranks in my experience. You really can just pull them straight off once the bolts are removed.

I think that if you back the rings out of the crank arms a little it will make it easy to remove the arms.

Thanks for the explanation and tips guys. :slight_smile:

In it’s current state I cannot remove the extractor ring either because the friction is too great for the puny spanner wrench required. In the morning (I live in an apartment) I’ll try using a nail and hammer to see if I can whack the ring loose.

And, yes, based on the other crank arm a removal tool is probably not required. Actually it might be that the non-tapered design of the crank interface contributed to the wear and creaking which prompted me to remove them for inspection in the first place.