Sibley Depot Wheelbuilding Class
Signed up for the wheelbuilding class at Sibley Bike Depot at the last minute. The class started at 6PM, and I signed up at about 4:15. This wasn't entirely my fault - I called the day before, but the guy who answered the phone was busy (he had his hands full with a room full of gradeschool-age kids - I don't know what sort of bike stuff he was teaching them, but I could hear a bunch of 'em in the background.) Then I tried calling multiple times today, and couldn't get through until 4:15. So there. Admittedly, I need to be more on the ball - I don't think I would have got into the class if someone else hadn't cancelled out. I also had to verify that the Depot membership that my sis gave me for my birthday last year was actually in effect (which it was) since I never got anything in the mail.
So anyway. About half the class had actual truing stands to use, the rest used the rear triangle of bikes in workstands. I don't think either way was much better than the other - I think either would work equally well, at least when you're at my novice level.
We were given a hub, a rim, and the correct number of the correct length of spokes. The geometry of calculating the correct spoke length requires, well, geometry (trigonometry to be precise) because you have to take the hub flange diameter, rim diameter, and lacing pattern (3 cross, 4-cross, radial, etc) into consideration. They didn't teach us the formulas - they just set us up with the correct length spokes. Most of us, at least. About 1/2 hour into the class, they discovered that some people had longer spokes - those people had to remove their spokes and start over - thankfully we weren't very far along. Bummer for them. Actually, it wasn't a huge deal because we weren't very far along at that point.
We had 36 hole rims, so each side of the wheel has 18 spokes. Lacing the first 9 spokes (every other hole on that side of the hub to the rim) were easy. Then you put the 10th spoke in the same side in the opposite direction - it'll be the first spoke that crosses the others. That one is also not too complicated. The complicated part is figuring out the correct location for the first spoke on the other side of the rim. If you don't get that one right, you'll be screwed and end up taking out that spoke (and all the others on that side) later and trying again.
Anyway, I won't go into any more detail since the process is tough to explain, and if you ever want to try, you'll buy a book or have someone teach you anyway. The truing process required more patience than anything, since you're trying to make sure that all points of the rim are equidistant from the hub, *and* make sure that the wheel has minimal wobble, *and* make sure that it's dished properly (evenly on both sides). It's a lot of trial and error, but it's not too bad if you periodically take a look at all three things (hop, wobble, and dish) and focus on the thing that needs the most work first. Then things seem to fall into place. Eventually I got to the point where my wheel still wasn't perfect, but it was pretty OK, and whatever I did seemed to make one thing or the other worse instead of better. That's when I said "good enough for now" and called it a night.
I can understand why wheelbuilding is considered both an art and a science. Coming out of the class, I'm pretty sure that if I had a book with instructions, and some practice, I'd have enough skill to make a wheel that would at least be rideable. Pretty cool stuff.
So anyway. About half the class had actual truing stands to use, the rest used the rear triangle of bikes in workstands. I don't think either way was much better than the other - I think either would work equally well, at least when you're at my novice level.
We were given a hub, a rim, and the correct number of the correct length of spokes. The geometry of calculating the correct spoke length requires, well, geometry (trigonometry to be precise) because you have to take the hub flange diameter, rim diameter, and lacing pattern (3 cross, 4-cross, radial, etc) into consideration. They didn't teach us the formulas - they just set us up with the correct length spokes. Most of us, at least. About 1/2 hour into the class, they discovered that some people had longer spokes - those people had to remove their spokes and start over - thankfully we weren't very far along. Bummer for them. Actually, it wasn't a huge deal because we weren't very far along at that point.
We had 36 hole rims, so each side of the wheel has 18 spokes. Lacing the first 9 spokes (every other hole on that side of the hub to the rim) were easy. Then you put the 10th spoke in the same side in the opposite direction - it'll be the first spoke that crosses the others. That one is also not too complicated. The complicated part is figuring out the correct location for the first spoke on the other side of the rim. If you don't get that one right, you'll be screwed and end up taking out that spoke (and all the others on that side) later and trying again.
Anyway, I won't go into any more detail since the process is tough to explain, and if you ever want to try, you'll buy a book or have someone teach you anyway. The truing process required more patience than anything, since you're trying to make sure that all points of the rim are equidistant from the hub, *and* make sure that the wheel has minimal wobble, *and* make sure that it's dished properly (evenly on both sides). It's a lot of trial and error, but it's not too bad if you periodically take a look at all three things (hop, wobble, and dish) and focus on the thing that needs the most work first. Then things seem to fall into place. Eventually I got to the point where my wheel still wasn't perfect, but it was pretty OK, and whatever I did seemed to make one thing or the other worse instead of better. That's when I said "good enough for now" and called it a night.
I can understand why wheelbuilding is considered both an art and a science. Coming out of the class, I'm pretty sure that if I had a book with instructions, and some practice, I'd have enough skill to make a wheel that would at least be rideable. Pretty cool stuff.
posted by equipoise at 10:56 PM
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