How to remove three piece crank?
 

Hello,
I'm a beginner when it comes to bike maintenance and I am trying to replace a crank. I think it is a three piece crank,
it is a made in China ProWheel Once 48T/CG 170mm and the BB set is VP BC73 113-68mm. I've removed the bolt
using an 8mm hex key but then I cannot remove the crank. The bolt I removed from the crank is 8mm. I have a crank
tool but the screw width is 12mm so that doesn't seem to be a right fit. Could someone explain what kind
of tool I need to remove this crank? I would really like to post pictures but I am not allowed to!

Thanks.
Bill

Test reply

Ok, you posted a bunch of photos here:
https://www.bikeforums.net/g/album/12445601

https://cimg2.ibsrv.net/gimg/bikefor...7326ad558f.jpghttps://cimg4.ibsrv.net/gimg/bikefor...4906f49d94.jpghttps://cimg6.ibsrv.net/gimg/bikefor...2759674d8b.jpg

You have what is called a "Cotterless Crank".

Take your crank tool, and back the middle screw out until it is flush with the outer shell.

The large outer screw should screw into the crank. Do it gently by hand, be careful not to cross-thread.

Once it is in tight, then screw the middle part down so it pushes the crank off of the spindle.

Note, your crankset doesn't apear to use washers. Some of the vintage cranks from the 70's will use washers that also have to be removed, or they will cause problems.

Your 1st pic is the crankset bolt. One with a "collar" around it. Often that's a 8MM. That, style, replaced the older cranksets that had a larger bolt, sometimes a nut. The Bottom Bracket, (BB), spindle could be threads, male or female. It's worth the bucks to buy a correct crank puller.
Older cranksets, had dust caps, that, used the same threads as the, ,, (correct ) crank puller. The 8MM Allen wrench crank bolt. Is easier, if riding around too. Or touring. Easier than toting a metric socket set around. Modern cranks are all over the place,, They have, internal & external bearings. A good bike shop or another poster here might be able to say it better. cheers\\