half radial rear wheel lacing question

[mattykhz]

Following a car accident I am finally getting my road bike built and to start riding again. I weigh 80 kgs.

I am looking at getting wheels built with the KinLin XR-200 rim laced to AC Micro front and RD205 rear in 24/28. I was thinking of using cx-ray spokes and radial front. Rear with half radial and 3 cross.

I seem to be getting conflicting information as to whether radial spoking should be on the drive or non drive side.

Reading here: http://www.geocities.com/spokeanwheel/lacingsr.htm states drive side should be radial

Reading here: http://www.sheldonbrown.com/wheelbuild.html states non drive side should be radial

So does anyone have any experience of either?

[Bill Bove]

Non-drive.

[mattykhz]

Any reason for this?

It seems there are those that do one, and those that do the other.

Hub design also confirms this with the Ligero being radial on NDS and Speedcomposites being radial on the DS.

Is this simply down to the design of the hub into a wheelset and so cannot be considered with regular hubs like the RD205 I will be using?

[mattykhz]

Also found this info from Wheelbuilder.com which also doesn't really answer my question but highlights the two methods:

Mixed spoke patterns can be found on many modern race wheels. These patterns commonly consist of a 2x pattern on the drive side mixed with a radial pattern on the non-drive side. One exception is Mavic's Isopulse lace pattern used on their Ksyrium wheels, which uses a radial pattern on the drive side. Mavic claims this pattern helps transfer load from highly stressed spokes on the drive side to the spokes on the left side of the rear wheel. This system is intended to improve the poor distribution of loads caused by the asymmetric geometry of the rear hub.

[markie]

When I used geared MTB's I would often get radial non-drive side and 3 cross drive side rear wheels built up.

If you think about a radial laced front wheel. If you applied a torque to the hub, the spokes would "wind up". Radial lacing does not work well for power transfer.

I would trust Sheldon Brown over everything else.

[ergott]

A couple of issues that don't make the answer as clear cut. With current hub designs, there is room to move the DS (drive side) flange further from center. One way I and many other builders have made up that lost bracing angle is to put all the DS spokes with the elbows on facing the outside of the flange. This is a strain on the hub so we cross the spokes once so the pull isn't directly outside. This makes the bracing angle better which for all intents and purposes, makes for a laterally stiffer rear wheel.

You can also do this with the NDS (non drive side). The only problem that can come up is dropping the NDS tension too much. You either have to use either tension all around which is possible with many rims out there or the NDS flange has to be closer which defeats the purpose.

Ideally, the DS flange could be over 1mm further from center from the best bracing angle (stock Shimano). This still allow for any clearance needed for the drivetrain. Then, you could normally lace the DS for best power transfer which is 3X for 28 (on larger flanges) and 32, 2X for 24 and 20.

The NDS flange should be placed to give you a reasonable balance between a good bracing angle and sufficient tension difference. The radial pattern is usually used to make hubs with a relatively narrow flange placement wider.

If the hub is designed for optimum flange placement, there would be no need for any radial patterns in the rear wheel. Ideally, the hub should be laced with the maximum cross pattern suitable for power transfer (as close to tangential) and the flanges as wide as the drivetrain will allow for lateral stiffness. These are the same requirements for disc brake hubs.

[mattykhz]

Thanks Eric,

So what would you suggest with my American Classic Micro 24 hole front and RD205 28 hole rear using xr-200 rims?

[ergott]

You can do radial heads out with the micro front. That is the laterally stiffest way to go.

The rear I would 3X both sides. AC don't like radial patterns on their hubs and I haven't tried to do otherwise. They are pretty narrow rear hubs so if you want a laterally stiff wheel, consider heavier gauge spokes for the rear wheel.

[jmc22]

If you plan to use you old hubs, you CAN NOT change the spoke lacing.

Thus if your old hubs were laced radial, 2x or 3x, you have to use the same spoke lacing on the hubs, in the same direction - usually what happens is the flang holes on the hubs tend to develop knotches , mostly in the area where the spokes's J-bend went towards the direction of the old spoke.

Changing the spoke configuration I believe will only cause you problems - with the new spokes breaking.

If you are going with new hubs - radial for the front, radial for the Non-drive side & 2x 0r 3x for the drive side is how most companies do it..

Attached is a link to the Reynolds website rear wheel
http://www.reynoldscomposites.com/images/items/2008/DV46C_R.jpg

Best of luck