As mentioned in the bike post from last year, I ended up replacing several more components on my bike, though some parts turned out to be much more difficult than I had anticipated.
Freewheel Ended up getting a 13T-28T (T=tooth, gear ratios are 13-15-17-19-22-25-28) Shimano freewheel to replace the old 14T-34T "Mega-range" freewheel that came with the bike. The new freewheel is smooth, has less of a silly jump from the lowest to second-lowest gear (28 to 25 vs. 34 to 24), and in my opinion the second highest gear (15T) is a better general gear. The highest gear (13T) also gives a nice little boost when going downhill too. After changing the Freewheel, I had to adjust the rear derailleur as well.
Chain It's always recommend that you buy a new chain when replacing a freewheel since an old chain can cause more accelerated wear, but in my case, the old chain had already been severely worn and stretched (by several percent) on its own. A trick I learned to test if a chain is worn (without a tool) is to take the chain off the bike, and use a ruler to measure from the centroid of the first pin-hole in a link to the pin-hole on the next link. On a new chain, this should be about 1-inch, while on a really old chain, it'll be quite a bit longer. The new chain I got (KMC-72) also happened to include a master-link which is convenient for taking the chain off without chain riveting tool.
Crank set This is where things went off the rails. I noticed one day that the bottom bracket was making a noise when pedaling hard, so I thought I would take the opportunity to just remove the old crank set (the chain rings and pedals) and replace the bottom bracket. Easy, right? I bought a crank set remover, screwed it into the drive-side crank arm, and screwed in the pusher, which then promptly proceeded to stripped all the threads on the crank arm.
After two weeks of research and trying everything under the sun, including: riding hard several miles to jiggle it loose, pouring boiling water on the crank arm to expand it, using an automotive puller tool, using an automotive pickle fork, hammering (a lot), getting advice from several other bikers, more hammering, and more. I came to the conclusion that I needed some serious help, so with the help of someone at the Google welding workshop and a handy plasma cutter, I watched as 30,000°F plasma sliced through the soft aluminum of the crank arm to finally free it from the bottom bracket.It's still a mystery to us exactly why the drive side crank was so stuck, but given how close I was to giving up and getting a new bike (a bike with a jacked up crank set is hardly useful), I am seriously considering hanging this crank arm like a trophy somewhere :) The crank set that replaced it was pretty much the same (28T-38T-48T, 170mm), and went in without a hitch once I got the new bottom bracket.
Ta-da! Crank set, post plasma cutting :)
Bottom bracket Once the crank set came off, replacing the sealed bottom bracket was pretty straight forward. The only issue was that when I took out the old BB, the two end caps that screw into the bike frame had rusted onto the frame, so I had to use a dremel and a wire brush to take off the rust, and then made sure I put on some more grease before installing the new one.
Miscellaneous Strangely enough, even though I bought a BB with the same length as before, the new crank set seems to stick out slightly further than the old one, which means that there is a bit of cross chaining when at the highest gear in the front and the lowest gear in the back. Not a big issue, since I'm rarely in that gear configuration though. I also recently moved back into riding in the middle front gear at a higher cadence than at the biggest front gear at a lower cadence. It's less tiring on the legs, and not actually slower than before (which is slightly counter intuitive since the gear inches are the same).
My goal for this year is to bike and log 1000 miles, but I'm already behind, which means I'll have to commit to biking a bit more to work these next few summer months!