Technical Q&A With Lennard Zinn
Dear Lennard,
I have recently switched from a 172.5mm crank to a 173mm crank for added power and leverage:
Should I expect knee problems? Should I change my gearing to account for the length discrepancy? Will I experience pedal strike more frequently?
–Fred F. Frederickson
The above is obviously a joke, since we all know the answers to those questions are: Yes; Yes; and Yes. In fact, I think we can all agree it should be illegal to change your crank length without a medical prescription. Think about it: half a millimeter, once per pedal stroke…if you ride 100 miles per week, after a year, you’ve flexed each knee an additional 2,000 kilometers! It’s really not possible to overstate the danger of this.
Actually, that is the Silver crank on my A. Homer Hilsen, which I removed in order to perform some bottom bracket maintenance, and I assume the rounded-up length is their way of trolling the sorts of people who obsess over crank length. I also spent a good amount of time on its stablemate, the Platypus, this past weekend, which sports 175mm cranks, though I’m thinking of going down to 174.5s so I can “spin” better:
While empty at this particular moment, I make frequent use of the basket, and think it’s the most convenient way to carry things by bike. Indeed, unless you’re a terminal weight weenie, there’s really no downside to having a basket on your bike–unless you happen to clip a fence post with it, as I did:
As you can see, the impact rendered it all askew:
This happened very early in my ride, and while it didn’t rub or in any way affect the bike’s handling I could not bear to look at it, and since I didn’t have a wrench on me to fix it I very nearly turned around to repair it at home, or simply switch bikes. But instead I gently twisted it back into a position that didn’t wreak too much havoc with my aesthetic sensibilities and pedaled on, only for my transmission to devour this stick shortly afterward:
It was in there pretty good:
Yet I managed to get it out, and I didn’t even have to stop again…until I started bleeding:
See, I’m of the habit of “choking up” on the bars so that my front finger is ahead of the brake lever clamp, and apparently I managed to gouge it on that stupid reach adjustment screw–which didn’t even need to be there anyway since I keep the lever all the way out. Why this hadn’t happened to me sooner I don’t know, and I’ve since removed both the screws, but at this point I figured I had nothing left to lose. So I did something I’d never done before, which is take the Platypus onto the Trails Behind The Mall, where it felt much better than I expected.
However, by far the best part was the sheer smugness of riding through on a basket bike as the “real” mountain bikers rode around the parking lot doing their pre-ride rituals. I mean, yeah, they probably rode off of tall things and stuff like that, whereas I rode slowly and kept both wheels on the ground, but they still look pretty funny testing their suspension and air pressure in their hockey shirts and Bettlejuice helmets:
See what I mean?
Then, when I emerged be-jorted and bloody-digited from the woods into the mall behind which the Trails Behind The Mall are, I locked the platypus up to an empty plant display in front of a large home improvement store:
And purchased this sort adjustable wrench:
Hex keys get all the attention when it comes to bikes, but it’s always good to have a short adjustable wrench.
First, I twisted the little diving board rack support thingy back into shape:
Then I snugged up the bolts, all of which was made easier by the offset head angle. Indeed, so pleased was I that instead of walking right back in and getting my money back I made it a permanent part of the Platypus’s onboard toolkit:
Every tool has a story.