Sun Dec 31 23:18:40 PST 2017

commuter bike, 920 miles later

Sixteen months ago I said the following:

I glumly regarded my future stretching out ahead of me, a future of cleaning my bike's chain once a week, and decided, screw it, I'm getting a new bike.

I am now cleaning the chain of that replacement bike once a week.

Let me tell you some things I wish I knew about internally geared hubs before I bought my bike.

1.) Chains stretch as they wear. You generally throw them away when they hit 0.75%. (0.075" of stretch across 10" of chain) A go/no-go gauge for chain wear, like the Park CC-3.2, is cheap and handy. (You can measure chain with a ruler or tape measure, but it's a hassle.)

Chain stretch is largely invisible on a dérailleur bike, since it has an automatic chain tensioner, (The little arm that swings down) but on a fixed-chainpath bike, like a single speed or internally geared one, you have to do it manually, by sliding the wheel backwards in the rear dropouts. This requires two wrenches, and ten minutes of time. This must be done weekly, or biweekly. If you let enough slack build up in the chain, then it'll bounce off the rear cog when you hit a bump, and you get to experience the joy of handling bike chain with your bare hands. (Unless you want to get chain grunge on your good winter gloves) Chains generally wait until the sun goes down and it starts raining to jump off a cog, as well.

2.) IGHs are filled with oil, which, per Shimano, have to be serviced after the first 1000 km, and then every 2 years or 5000 km thereafter. (My Nexus 3 started making noise at 600 miles, right on schedule) A bike shop will charge you $40-50 to do it. Want to do it yourself? The OEM oil costs an eye-popping $60 per litre. This guy has been using dollar store ATF on his, and it seems to be working fine, but this is not the maintenance-free dream I was promised!

3.) This is a topic of hot debate, but some allege that fixed-chainpath bikes eat chains more often. But I've got a Hebie Chainglider on there, which should protect the chain from dirt, and make it last longer, right?

Well, no. The factory original chain lasted just 700 miles before hitting 0.75% on the gauge. I threw the old chain away, along with the chainglider. As far as I could tell, it didn't do anything at all.

So now I've got my bike up on the stand every other week, to tension the chain, and running it through the chain cleaner now that it hangs out unprotected. My original reason to buy the bike is now completely obliterated. Oh well.

It strikes me that there is a lesson to be learned here about technological systems. As a computer guy, I'm used to slam-dunk upgrades-- this year's Intel chip will be authentically better in every single way than last year's chip, a 2 TB hard drive is better than a 1 TB drive, etc.

This is not true of all things! AC induction motors, for example, basically haven't changed in a century. Mankind quickly figured out the most efficient way to convert electrical power into motion using iron and copper, and there progress stopped. There's no AC motor today that's "better" than a motor made in 1910, no way to get more power without needing more coils, or more voltage. You can shave tenths of a percent off of 98% efficient, but there's no route to 120% efficient.

You see echoes of this all the time in a mature technological system like the bicycle. If there's a better way to do something, it was done decades ago, now all that's left to us in 2017 is choices between tradeoffs. Drum brakes are weatherproof in a way that rim brakes can't be, but heat rejection is terrible, (All the hot parts are sealed inside an aluminum can-- the price paid for being weatherproof!) braking counterforce is applied unevenly to one side of the fork with a single reaction arm, it weighs more, and in the case of my 70mm drum brake, you just plain can't brake as hard.

Disc brakes? You have to use hydraulic force multiplication in order to get the same braking force as rim brakes with a shorter moment arm. Force multiplication means length of travel is divided, so the pads have to be thinner, making them wear out even faster than rim brakes. The rotor has less mass than a wheel rim, so it heats up faster. All is compromise, trading one good for another good.

Not to say that the Windsor's totally worthless now. The dynamo hub and lights still work way better than the assortment of battery powered lights I had on the Trek. It has a kickstand, which is unforgivably omitted from all sports bikes for weight reasons. After falling off the bike thanks to ice in the parking lot at work, I swapped the 32mm Panaracer touring tire for an insanely beefy 42-622 Continental Top Contact Winter II tire on the front wheel. It mounted up just fine on my 20x622 rim, but has almost no clearance between it and the fender-- if I was going to do it again, I'd get the 37mm version.

You wouldn't expect there to be much of a different between winter tires and all-seasons, since they're both... rubber... but winter rubber compounds are actually quite a lot better on ice. Plus, the contact patch on the 42 mm tire is a hell of a lot bigger, which should help some just by itself.

So that's 2017. Check back next year, when I will have talked myself into buying yet another bike for one reason or another.


Posted by Samuel Bierwagen | Permanent link | File under: Etc
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