Bikes are really incredibly simple machines and very easy to work on. I suppose if you're not mechanically minded, that might be a different story, but I did an apprenticeship re-building turbines and 10 cylinder diesel engines where I could crawl into the crankcase. My Dad is also a Millwright and I spent hours and hours as a kid messing around with him in the shop, building all sorts of things and fixing our cars. Maybe their not so simple to everyone, but I find them incredibly easy to understand and work on.
Anyway, the person who had the bike previously didn't take care to make sure that the cranks were properly tightened. I'm sure they kept coming loose and they'd get out their trusty Ukrainian socket set (crescent wrench) and tighten it up a little and figure they were good until next time. With the square taper axle, this will wreak havoc.
SO I took it out so he could take it in to get a new one. The crappy thing was that I didn't yet have a splined bottom bracket removal tool. I buy my tools on a need to use basis, and in all the bike messing around I've done, I still haven't had to change out a splined bottom bracket. Until now.
He ended up going into the shop to get the bottom bracket after we measured it still in the bike, and I told him that if he would pick up on of those those BB splined sockets, I'd use it on his bike and pay him for it. Always looking for an excuse to buy tools, and I don't get to bike shops all that often.
He came back with all the parts (new BB, chain rings, and crankset) and I put it all back together for him. When I was done I asked how much I owe him for the tool. He told me, "it's yours for all the work you've done." Sweet!! I'll take deals like this any day. I had also adjusted his derailleurs, brakes and headset, so it's not like it was just 15 minutes. In all I spent about an hour on the bike.
I was just doing it because he's my friend and it's one way I can help promote cycling and get people out on their bikes. I give free tune ups all the time to people at work and my neighbours, but to get tools for doing it? Pure gravy.