Sunday, January 31

Building a Wheel

A while back, here, I got a good long walk as a result of using Armadillo tires on an old rim that was NOT a hook bead rim. Chandra expressed interest in the process, and it's really pretty simple. It's even simpler if you are not cheap like me, and reusing old spokes. My considered advice is to do as I say and not as I do and use new spokes.

Normandy French Hub - Still Useful
After All These Years
Anyway, here's the basic process. Pick out a hub in good condition. I chose an old Normandy hub for this project. It was off of something French or English that had long since vanished and was hanging from the ceiling of my parents' garage in Seattle. So it'd fit into carry-on baggage, I dumped the rim and brought back just the hub and spokes. Those old Normandy hubs mostly have 36 spokes which make for a strong wheel build. They also last forever. The one I used is at least 30 years old and the bearings are still good. One nice thing about building a wheel - it's really EASY to get that old hub clean when there are no spokes attached to it!

Next, pick out a rim. Your LBS can get one of these for you. I just happened to have a 27 inch hook bead rim AND, this is CRITICALLY IMPORTANT, the rim had the same number of spokes as the hub. Conveniently enough, the rim and hub needed the same spoke length as the spokes I salvaged. Thus, I only had to buy a few spokes. At a buck a pop, the cost of spokes can add up if birds say "cheep" when they see you. Now, in general, you're well advised to follow my advice instead of my example and use nice, new, uncorroded and unfatigued spokes from a reputable supplier such as Wheelsmith or DT Swiss. Let's further suppose you don't have a combination you are sure of the spoke length for your proposed build. Well, you COULD try this by trial and error, but you may well be in luck. There are spoke length calculators here (this one is complete with a lot of common rims and hubs preloaded to reduce your chances of error) and here.

Old Spokes
Make Things Tougher
At this point, I'll suggest that I hope you are not using this post as an authoritative guide for your own wheel building. There are MANY MANY good sources for that, and I suggest you avail yourself of them. If you Google "bicycle wheel building" you'll get about 2.5 million hits, and the first of them, Sheldon Brown's, here, is excellent. There's also some good stuff on the subject in Forester's "Effective Cycling." While you're on Google, don't forget to click on the "video" tab and watch some of the excellent videos on the subject. Bottom line is that wheel building is NOT black magic. It just takes a bit of time and care to get things right.

Anyway, since I was building up a new wheel and had my old one as a guide for the spoke pattern, I reduced my chances of getting things wrong by using the old wheel as a guide. From my past wheel builds, the thing I'm most likely to do is get the key spoke next to the valve hole misoriented. This doesn't really result in the wheel not working, but you want the spokes going "away" from the valve so it's easier when you put air in. Go read some of the experts, and look carefully at your good wheel that's already built. It'll make sense.

When you put the spokes in, the first lacing group is simple. All you have to remember is you put all the spokes in from the same side of the hub and they go in every other hub hole. They go in every 4th rim hole. Don't thread the spokes into the nipples any more than is necessary to keep things together. If the holes in the rim aren't all in a straight line, make sure the offsets are oriented properly so truing pulls the rim easily.

First Lacing Group
After the first lacing group, assuming you got things right relative to the key spoke, you have your first big chance to really mess things up when you flip things over and begin on the second lacing group. Everything is offset one hole from that first group. If you get confused by diagrams, use your existing wheel and count holes carefully. If you get the first spoke in right, then the rest are simple since it's just "every other/every 4th & leave things loose" again. After you finish this second lacing group, you've got half the spokes in and ready to start the basket weaving part of the job since, if you did trailing spokes first, you get to do the leading spokes.

For the leading spokes, if you used an old wheel for an example, do the same for the third and fourth groups. Pay careful attention to which spokes the leading spokes go under and over. As in the first and second groups, the first spoke of each group is the one you need to be careful about so you don't get things out of whack. Count holes and look at the old wheel and you'll be OK.

After getting the last group done, go around and tighten up all the nipples to finger tight, and then get them taut and even much as you would the cylinder head bolts on an engine. If you're using NEW spokes, they'll all be the same length and you can just match up the thread count exposed. At this point, bend spokes as necessary, as recommended by Sheldon so they come out of the hub straight and clean.

Keep working things tighter bit by bit, but before you get serious about actually TRUING the wheel, do what Forester recommends and take the wheel out and really PUSH on that rim, working around it, and flipping it over. You want to work out the residual forces so when you true the wheel it'll STAY true.

Then, use a fork or a truing stand to true the wheel. Work slowly, pretty much the way Sheldon Brown recommends, with quarter turns. Opposites to move the wheel over and together to pull it in or out. Truing is not a job for the impatient. I imagine some can do it quickly, but I can't. I got a low cost truing stand from eBay. It works fine for the amount of truing I need to do. With the stand, it's easy to take my time and true away while a movie runs.

Affordable Truing Stand Makes Truing More Pleasant
But it Really Isn't Necessary
A bit of trivia: If you ever watch "Breaking Away," you'll note that he twirls that spoke wrench several turns. Do not EVER do such a thing. Quarter turns are plenty.

5 comments:

m e l i g r o s a said...

wow this is cool! you're so crafty :D
I don't think I'll have the accuracy to do such things like these, ummm jittery fingers he hee

Rat Trap Press said...

Great post! Now I know who I'm going to call for help when I try building a set of wheels.

Chandra said...

Steve,
You done it again, another great post!
I did watch "Breakin' Away" but can't remember the scene vividly.

Do you think building a wheel on a geared hub will be much harder?

Peace :)

Velouria said...

Oh cool, I am just about to get started on this with the people at my local bike shop. I am beyond impressed that you are doing this on your own, with only online articles and your old wheel to guide you!

Steve A said...

A wheel with a geared hub or a generator is just the same except the geared hub will be centered (dished) to compensate for the gear. Learning from someone who does it for a living is best but it really is fairly simple technology.

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