Monday, August 2, 2010

A Cambridge Education

Tonight was the first night of my advanced bicycle maintenance class at Broadway Bicycle School. This is a 4-week class that covers stuff I'm mostly reasonably accomplished at -- repacking hubs and headsets, adjusting a front derailleur, and truing a wheel. It's that last one that I'm there for -- I can't true a wheel to save my life (possibly an exaggeration), and I want to learn how to build wheels, and the two sort of go hand-in-hand. I was able to talk my way out of taking the beginner class, because I've built bikes up, and stuff. But I couldn't answer the wheel truing question in the affirmative, so I have to take this one as a pre-req' for the wheel building class.

Though I know how to do most of the things on the syllabus, the class also offers an opportunity to do a few non-routine sorts of things: First, to get into Cambridge every once in a while. Second, to learn some tricks from an actual bike mechanic. And third, to work on problem spots on a few of the bikes under my oversight. That last one might actually be pretty routine, for me. Still...

You're supposed to bring your bike to class every week so you can give it an overhaul in class. Which is great, but no one of my bikes really needs an overhaul -- I spend too much time poking around at them, and they all work pretty well. So my plan was to bring my sister Amanda's old but nearly unused Trek 930 mountain bike to class. I even picked it up on Saturday afternoon for that purpose. The thing is, though, it's really never been used, and it's a decent bike (largely Shimano STX-RC components, though with a few cheapo exceptions) and to be honest, I'm not sure it really needs much more than having the squirrel poo hosed off (which I did before it went onto my roof rack). Some fresh chain lube maybe, and some actual air in the tires. Oh, and the little locknut that screws down onto the Presta stem to keep it from pushing in when putting air into the front tire. Otherwise? Pretty much ready to ride.

So what to do? Spread the class across my fleet selectively. For example, tonight was "repack a rear hub" night. Remembering how awful the rear hub on the trailer bike was when I first overhauled that bike, I decided to bring Ava's new-to-her Gary Fisher into class. And whoa Nelly, did that cheap steel rear hub need a repack! The grease was clean and the races and cones were without any evidence of wear. But it had been adjusted so tightly at the factory that the bearings were snatching badly at the axle as I spun the wheel. So I pulled it apart, tossed the seven old ball bearings and their retainer cages, and popped in nine quarter-inch balls per side, sans retainers, in their stead (mechanic's tip, there -- lose the retaining cages and add more balls). Plus a lot of grease. Adjusted, it still wasn't the smoothest hub I've felt (by a long shot), but it should loosen up as Ava rides it a bit more, and it's much better than it was. I finished up pretty quickly and spent few minutes adjusting the rear derailleur cable while the bike was in the stand. I think it must have slipped, because even with the adjuster barrels all the way out, it couldn't hold first gear. An easy fix.

As I was hoping I would, I learned a couple of tricks. First, there was the lose-the-cages thing I already mentioned. Second, a ballpoint pen is a good way to check the cones and races on a bearing to see how smooth they are. If they're pitted, you'll feel that right away with a pen tip rolling across their surface, and they'll need to be tossed and replaced (which probably means the whole hub or even the wheel, in the case of the races). And third, just when I had the axle just about perfectly adjusted, for smoothness, I was told to wrench the outer locknuts together a bit, to snug the cones down just an iota more. The hub feels grittier that way, but I was promised that the balls will settle in pretty quickly, and the hub will smooth out without getting slop in the adjustment. This makes sense -- I often find I have to snug the cones down a bit a few rides after a repack. I just never thought about overtightening them just a bit to start, imagining bad compression forces at work on bearing surfaces.

I also learned how much better a real bicycle mechanic's stand is than my home-made one. I really should work out a more stable base platform. Mine rocks all over the place as I work, due to flex in the plywood, even with the reinforcing plank I added. Maybe a diamond steel plate, rather than plywood! It wouldn't be very mobile, but it would certainly be stable. The clamp is a bit handier on a real stand, as well, relative to the Pony clamp on mine. And I really enjoyed snooping around the shop and having all those tools at hand, hanging neatly from a board. I need a better layout than what I have -- I end up misplacing tools all the time, because everything is scattered around my barn floor and a few nearby work surfaces.

Anyway, having repacked Ava's rear hub, I'll tackle the front hub on my own, and also see to the bottom bracket and headset. I won't bring it back to class again, because it doesn't have any problems in any of the areas remaining to be covered in class. Plus, I earned several laughs and jeers as I rode it (standing up) a block from the car over to Broadway Bicycles. I'm sure I was quite the sight, actually.

Next week will be headset overhaul night, and I'm going to bring Juli's Fuji in for that. I lubed the headset in April or so, but didn't replace the balls. And when I had the bars and stem off a few weeks ago, I noticed the headset was a little stiff and uneven in its rotation -- definitely not up to snuff. I loosened it a bit, but then when I watched Juli coast down our hill last Friday (in a one-on-one day for us) I saw that the bike was obviously shimmying badly. So I'm going to snug it back down again for now, but bring it to class next week. It may need more than an overhaul -- the old 105SC part may need to be replaced. But there's really no better way to figure that out than to bring it to class, get it apart and have the instructor give me his thoughts.

The week after that will be wheel truing. The Shogun wears the oldest wheelset in my fleet -- Shimano 600/Mavic wheels originally from Allyson's Bertoni. They're nice wheels, and very comfortable. But both of them could use a little truing up, and the rear is slightly out of round. I'm not sure if I'll be able to address both of those problems, but it's worth a shot. So I'll grab the bike back from Erik that Sunday night, take it to class on Monday, and drop it back that night after with straight wheels -- he shouldn't even miss it.

The final week will be front derailleur adjustment, and I've no idea which bike to bring. Maybe the Fuji again, or maybe the Motobecane. I don't really have any front derailleur issues right now, so I'll have to wing that one.

In addition to the bike stuff, I've already learned a couple of things about Cambridge, too. First, the Mass Pike exit to Cambridge doesn't just back up at morning rush hour, it also backs up at evening rush hour. It took me a full hour to get to Broadway Bicycles and park. That's the second thing -- parking sucks. Cambridge is not a city for a car owner, it's a good place to have a Zipcar membership, a bicycle and a T-pass. Plus feet. Third, it's a neat old city -- low and reasonably green, with people bustling about everywhere, bikes all over the place, and little holes-in-the-wall serving any kind of food you could wish for. Next week I'll give myself time to snag dinner before or after class, in either Central or Harvard square, both of which are pretty close to the shop. The fourth lesson really isn't unique to Cambridge or this class, because I noticed the same thing when I did that cooking class months ago -- it's more fun to do stuff like this with a friend, and I need to find someone to sign up with me! Finally, the fifth lesson is also not likely unique to Cambridge -- that as tolerant as it might be, folks will still laugh at a grown man on a kiddie mountain bike.

In any case, it's "so far, so good" with the class. It was a fun and productive evening, and I'm looking forward to the three remaining nights -- and ultimately tackling that wheel-building class!

All for now,


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