8

Reading a review of a bike trailer one of the commentators noted that the wheels were laced radially:

enter image description here

It is a 16" wheel. Does this configuration have some advantage making it a good choice? I always had the impression that wheel spokes were crossed for greater robustness.

Cynically I suspect this could just be a way to make the wheels a little cheaper - but cheaper doesn't necessarily mean inferior, or does it in this case?

  • Does this trailer have rim brakes? Probably not, but its possible. – Criggie Mar 21 at 23:35
  • It’s stronger, lighter and cheaper. You only need crossed spokes to transmit torque (i.e. rear wheels or disc brakes). – Michael Mar 22 at 6:46
9

Crossed spoke lacing is primarily necessary to transmit torque from the hub to the rim, rather than for increased strength, although I suspect hub flanges have more strength when loaded by a crossed spoke. Given a trailer wheel will carry a lower load than a bicycle wheel this does not matter.

| improve this answer | |
  • 4
    Torques would be from pedaling or braking... trailer has neither, is that what you mean? – UuDdLrLrSs Mar 21 at 14:08
  • 3
    Yes, pedaling, disc or drum brakes. Obviously rum brakes operate on the rim. – Argenti Apparatus Mar 21 at 15:06
  • Got it. So then in this case, radial is probably just cheaper to make? – UuDdLrLrSs Mar 21 at 16:14
  • 6
    @ArgentiApparatus - Where can I get some of these rum brakes??? – Daniel R Hicks Mar 21 at 17:29
  • 2
    While the magnitude of this effect is totally irrelevant to trailer wheels, it should be noted that cross lacing requires slightly longer spokes, which does decrease lateral stiffness slightly. So, no torque = radial spokes are slightly better, torque transmitted = cross lacing is a must. – cmaster - reinstate monica Mar 21 at 17:59
5

A consideration is the diameter of the wheel, compared to the hub diameter. The smaller the wheel, the more difficult it is to "cross" the spokes.

| improve this answer | |
  • 1
    I'd say, it's the angle at the rim that makes cross lacing difficult. And that angle depends on a) the rim's diameter, b) the hub's diameter, and c) the number of crossings relative to the number of spokes. With the tiny hub in the picture, it should be rather trivial to cross the spokes twice. However: What's the point if there's no torque to transmit? – cmaster - reinstate monica Mar 21 at 17:55
  • 2
    @cmaster-reinstatemonica a crossed lacing pattern is supposed to be stiffer than a radial pattern, due to the additional crossing points acting as supports for each spoke. A trailer wheel is always vertical so there are lateral forces when cornering, that are different to a bike wheel that leans, so its slightly like a car wheel in that regard. – Criggie Mar 21 at 23:38
2

Radial is cheaper, simpler, and perhaps lighter.

I think that hub flanges are stronger when spokes are laced with some cross. I also think the spokes stay tight better, and it looks better, so my preference is to lace with some cross even in case of front rim brake wheels or trailer wheels. But the default answer is it doesn't really matter for those types of wheels.

| improve this answer | |
  • 1
    Why do you think so? – ojs Mar 21 at 17:34
  • 1
    Another point - radial has a visual appeal and is noticeably different to a crossed lacing pattern. Whether its prettier or not, "different" can help a product stand out at the shop/catalogue/website. Doesn't mean its better for the user, just for sales. – Criggie Mar 21 at 23:40
  • 1
    Radial is cheaper, because radial is handily the simplest pattern to lace, fastest to lace, and easiest to teach somebody to lace. This is probably the biggest benefit. Hub flanges are stronger when spokes are laced tangentially; this is common sense and my own experience, and some mfgs. don't spec their hubs for radial nor warranty them if they are laced radial. Spoke loosening is debatable, but I think tangential nipples stay tight slightly better due to the slight torque. For trailers it doesn't matter. I'm guilty of choosing lacing pattern based on the spoke lengths I have in my drawer. – BetterSense Mar 22 at 18:47

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

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