So I just joined this forum as I just go my first used bike, and I'm pretty sure its very similar to the 10 speed you have. I couldn't exactly tell from the picture, but if it is the same as the one I just picked up, the crank on this bike has a bolt with a nut on one end and a smooth circular head. My question is I've looked around online quite a bit the past couple days, and can't seem to be able to find out how to remove it, as it doesn't seem to be similar to all the other's out there. Hopefully you or someone can point me in the right direction because I really need to get it fixed so I can start riding!

Also, good luck on your projects this summer!