Saturday, June 18, 2011
Of single speeds and chain whips (sounds like leather vests or rubber underpants ought somehow to be involved, doesn't it?)
Despite the fact that I've climbed every steep hill in my riding area on my single-speed with the 18 tooth rear cog, I have aspired for some time to put on a 20- or possibly 22-tooth rear cog. I've got another single-speed with an 18-tooth cog which I will keep for when I'm feeling masochistic. Having never changed a cog before in my life (a major accomplishment last week was to replace a bottom bracket bearing in the same bike), I knew special tools (not the kind Congressmen like to photograph) would be involved. So I looked at the bike, looked at pictures on the Internet, and got lucky (no, not those pictures, and not that kind of lucky): I actually got the right freewheel tool the first time, without having to reorder anything. But then I came to terms with the fact that I needed a chain whip--another mysterious tool whose use I had never grasped until I needed one. Since the cog is self-tightening in riding use, and since it's the nature of the freewheel to spin freely the other direction, the chain whip holds the cog while you unscrew (using the freewheel tool) the ring that holds the cog in place. Chain whips are not that expensive, but I wanted the job done now, and the nearest shop that might sell me one is thirty miles away. So again to the Internet--where someone pointed out the not-until-then-at-least-not-to-me obvious, which is that you can wrap an old chain around the cog, clamp onto the old chain with Vise-Grips (or in my case, cheap Chinese locking plier knock-offs), and wallah, you have a serviceable chain whip. Which is the only useful bit of info in this post. The ring was on so tight that I had to use a lever on both the pliers and the wrench, but the job is done.