tallanasty

I'm planning on building a wheelset, and I've seen some pictures of some bikes that have the non drive side of the rear wheel radial-laced, while the drive sice will be 3X or something else. What I'm asking is why would one side be laced radially, while the other isn't? Is there some kind of extra force exerted on the spokes on the drive side that would necessitate them being laced differently? I figure the drive side would experience some stress, but does that stress really go into the spokes? If so is there some kind of benefit to having one side radial, or is it just a style thing?

MrCjolsen

Were these geared bikes? A dished wheel means a weaker drive side, and so if you are going to NOT radially spoke anything, it would have to be the drive side of the rear wheel.

Every spoke I've ever broken has been on the drive side.

Wil Davis

Use the search function. Heed Sheldon Brown -

- Wil

11.4

This being a fixed gear forum, I'd qualify the comments below by saying that they only pertain to dished wheels, which a fixed gear wheel basically ain't. There's no reason to do it on a fixed gear wheel.

On road wheels, with the extreme dishing required for modern 9 and 10 speed cassettes, the drive side gets quite over-tensioned, while the non-drive side ends up significantly under-tensioned. Under-tensioning spokes allows them to move a bit more and oddly enough can cause more breaking on that side. Plus, when that side has a 3 or 4 cross lacing, there's further flexibility created by the lacing arrangement. Then you have one side that's pulled super-tight and one side that is almost not tight enough to stay stable. So if you sprint or climb hard on the wheel, you will never pull the rim out to the left, but you can definitely pull it out to the right (or drive side). One solution to this problem is to radially lace the non-drive spokes -- it increases the static tension somewhat and it also lessens the amount that the rim can move because the non-drive spokes immediately become loadbearing if there's pressure on the rim to move toward the drive side.

There's a ton of debate over what works better, and why. I build a good wheel and didn't have wheels fail when they were built 3- or 4-cross on both sides, but I also find they're a bit stabler when I'm doing intervals or a road sprint if the non-drive side is radially laced. Now many hub manufacturers won't warranty a radially laced hub, but more and more are acknowledging the practice and building their hub flanges a tad stronger (current Shimano Dura Ace, DT Hugi 240's, and of course Phil Woods -- and probably some others I don't remember offhand -- all accept radial lacing). If the hub warranty is in place, I don't think there's much reason not to do it. There are aerodynamic arguments in favor of radial lacing that I think are mostly hoo-hah, but other reasons that make more sense. Radial lacing is common on some high-end pre-built wheels, but remember that tensions are ferociously high on those wheels and they have special design issues at work. So why do it?

1. arguable increase in stability and spoke life on a heavily dished rear wheel (the important reason).
2. easier and faster to lace (don't laugh -- it makes a lot of people adopt the practice).
3. easier to clean the spokes and hubs (equally silly, but it does matter if you get your bike mucked up a lot).
4. Much more of a bling look (actually, this is the most important reason).
5. Aerodynamics (I put it in just in case you want to argue the point -- I don't believe in it).

Why not?

1. if the hub warranty is voided (though I admit to doing this all the time anyway).
2. if you don't have significant rear dishing, as on a track wheel.
3. There's a famous picture of an exploded Campy C-record hub with the flanges busted from a reported radial lacing job. Well, if you look closely the entire hub self-destructed. Those hubs had a tendency to do this, but that particular photo showed a hub that had been in some kind of accident where a car's wheel or something like that caused a massive deflection in the wheel. You can see from how the metal is bent in the hub. Well, if you think your hub will explode, then don't do it.

vobopl

The drive side transfers the torque from the cog to the rim. The design of some high end Campagnolo hubs for geared wheels takes that into account. These narrow in the middle hubs do not transfer too much torque to non drive side and have oversize spoke head circle at the same longitiudal plane as pawls transferring the torque from a casette carrier. Hence, the load patterns for the drive side are different than non drive side and the spoke patterns reflect that.

There is at least one hub (Mavic?) when this is just the opposite - hub is designed to transfer the torque to the non drive side (because it is less dished and can handle some more load) which is cross laced, while the drive side (heavily dished) is radial.

tallanasty

thanks