Bicycles Stack Exchange is a question and answer site for people who build and repair bicycles, people who train cycling, or commute on bicycles. Join them; it only takes a minute:

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

I've done quite a few wheel rebuilds to make them stronger, but haven't built up a wheel around a PowerTap (SL+) yet. This will be for a training set for a fit triathlete. Raw weight is not an issue, but he's probably putting a few watts done for hours at a time.

My inclination would be to do my "standard" rear wheel build, drive side X3 and non drive side Radial, but wonder if there are pros/cons to other lacings when power is involved.

share|improve this question
I really wonder if there are any difference in torque transmitted by radial vs. non-radial flange of the hub. – heltonbiker Jun 28 '12 at 16:38
That hub appears to be larger in diameter than the normal hub. This means that there's less distance to achieve spoke crossing, and the spokes will approach the rim at a more oblique angle. For these reasons you may want to use a 2x lacing, and, for strength, do both sides 2x. (Hard to say until one sees the hub in the context of its rim, though.) I can't see how the power meter function could add any (significant) additional load/stress, though. – Daniel R Hicks Jun 28 '12 at 17:14
up vote 5 down vote accepted

According to the FAQ on their website:

Note: PowerTap hubs must be laced with a minimum 2 cross pattern to avoid damage to the hub and maintain the warranty."

That suggests that making the non-drive side radial could lead to warranty issues. Radial lacing does stress the flange more than tangential lacing so many hub manufacturers do not allow it. To work on a driven wheel it also needs a certain amount of torsional flexibility in the hub which large-flange solid hubs don't have (Rohloff, PowerTap for example).

I would go with a ye olde traditional 3x lacing, and lean more towards 2x and bladed spokes than other options if the rider wants to spend more money.

share|improve this answer
+1 for the reference to the PT FAQ. The number of crossings will also depend on the depth of the rim: you may not be able to get a 3x on a deep rim (though you shouldn't need to -- a relatively shallow training rim and a wheel cover will work fine for almost all triathlons). To get consistent readings from the PT's torque tube you should not use radial lacing on the left side. – R. Chung Jun 29 '12 at 14:48

I have built a Sheldon Brown POWerwheel to a home-made recumbent I have (photo).

Although the idea seems a bit absurd (two leading spokes for each trailing spoke), it worked great for years without any issue, gave a very discrete visual (you only notice it is a powerwheel if you look close), and in the end it is possible that it actually MAKES a difference (at least it doesn't do any harm).

enter image description here

There are some conditions, though:

  • The wheel needs to have number of spokes multiple of three (36, 24, etc.);
  • Your client must "buy" the idea;
  • Both of you cannot be overconservative about wheelbuilding...
share|improve this answer
Cool stuff...I think I may have to build a wheel for myself like this. I'm guessing you'd want to use a rim that doesn't have a big bias on the drilling (holes are more centered with less angle). – Ken Hiatt Jun 28 '12 at 18:57
@KenHiatt Actuallly the spoke angle at the flange AND at the rim are the same of a regular crossed pattern (Don't remember if you must use the same spokelength of a 2X or 3X pattern, though) – heltonbiker Jun 28 '12 at 20:12
+1 purely for the POWerwheel reference. But the interesting lacing pattern is also amusing. – Kohi Jun 28 '12 at 23:22

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.