Sunday, November 30, 2008

Cookies and wheels!

Long time readers of Spokes of a Wheel might recall an early post in my "How to Talk to Your Bicycle Mechanic" series in which I discussed the virtues of cookies in transacting business with your bike shop.

Well, Saturday morning, a customer came in to pick up a set of wheels I had built up for him... and brought this container of cookies! And wow are they good! And what an assortment.

By the way, bonus points for any bike geek who can identify the black gizmo in front of the cookies.

Now, this also brings up a question I've been asked several times lately... Why would you have someone build you a set of wheels from parts, rather than just buy a pre-built wheel? Well, in this age of mass produced products, injection-molded gadgets, and robotic assembly machines, there are still some things that are better when "lovingly hand-crafted" as I like to describe my wheels (tongue firmly in cheek... I do NOT take myself that seriously).

Most wheels on new bicycles are built by machines, as are many standard, "off the shelf" replacement wheels. And that is the most economical approach.. chances are, if you damage a wheel on your bike, and you're a typical, casual rider, your local shop will sell you a pre-built wheel from a mass-production house. And in most cases, that will work just fine. You'll probably find that the wheel goes out of true fairly soon, but that can be addressed with a followup truing job, and the wheel will "settle in" and remain round and true for a good, long while after that.

But what if your needs are not so run of the mill? What if you commute regularly on bad roads, with a load? Or you want to take your bike on extended, loaded tours? Or you're heavier than most riders? Or what if you simply want a very specific combination of hub, spokes, and rim? That's where a custom, hand built wheel fits in. If you come to me with some variation on one of the above situations, I'll talk to you and ask you more about the kind of riding you're doing, how often you've had problems with your wheels... I might even ask what you weigh. Then, if I believe you'd be best served by a hand built wheel or wheels, I'll tell you so and why.

So, why? Aside from being able to specify exactly the right components, there are a few other advantages to hand built wheels. Probably the biggest difference I notice between a factory wheel and one built by hand by a competent builder, is stability and reliability. The reason for this is that a good builder will put the wheel through a process called "stress relieving". This is where the builder applies a sizable amount of stress to the spokes at several points during the build, in order to make sure they are properly "settled in" in every way. Spokes have a tendency to "wind up" or twist when the nipples are tightened, and applying a load to them while building will relieve that wind up and if done properly leave you with a wheel that will remain round and true for a long time with little or no touch up required.

In addition, a hand builder will check the tension of each spoke, either using a sense of "feel" earned through experience or using a tension gauge. This results in a wheel with higher, more even tension in all of the spokes than in a typical factory wheel. Due to the demands of mass production, I suspect factory wheels, whether machine or hand built or some combination of both, have lower tension, in order to play it safe and speed production. In addition, due to inadequacies in the machinery, or the speed required when building hundreds or thousands of wheels, tension from spoke to spoke varies a lot more in a factory wheel. Uneven tension, and low, uneven tension, results in a wheel that is just waiting to go out of true, especially when the stress relieving step is left out.

I'm sure someone who has spent a lifetime building wheels professionally could explain it better, but in a nutshell, those are the main reasons I can think of for having a wheel or set of wheels built for you by hand by your local (or maybe not local) wheel builder. If you think you might need such a thing, stop in and we (or you and your mechanic, where ever you are) will talk. It's a more expensive option, but for some folks, absolutely the best choice. And cheaper than going through a series of inadequate factory wheels.


Vofsking 12 said...

Isn't that little black gizmo the derailleur for a Brompton?

Tim said...

Close! It's the chain tensioner for a Brompton. The actual derailleur is just a little "fork" that slaps the chain from one of the two sprockets to the other, much like some of the derailleurs that were around before the modern "parallelogram" style came along. Good eyes, Vofsking.

beth h said...

I thought it looked like a chain tensioner, but not for any bike I'd seen up close. Amazing little gizmo. And those cookies look *homemade*. A score, my friend.
(All they ever bring ME is very pale ale. Harrumph.)