I have extensive personal experience with these--particularly with the Ghisallo brand, which are the only ones still available new, to my knowledge.
They are very strong in the normal load directions. In other words, they are very resistant to normal stresses from pedalling or even hitting potholes. Partly this is because they are much more flexible than metal rims.
However, if hit from the side, say, in a crash, they will shatter. Sheldon is absolutely right that they can be a hazard in such a situation.
Their other limitation is resistance to moisture. The wood swells a lot when wet, and if the spokes are laced too tight (read as tight as is normal for metal rims) the rims will de-laminate if they get really drenched. This would be less likely if the varnish was in really good shape, but if they are used with brakes there won't be any varnish on the sides--just where the laminations are exposed to moisture.
They will also shrink a huge amount in dry conditions. In our area, this meant I had to lace my wheels very loosely so that in the wet season the wheels wouldn't come apart. In the dry season the spokes were so loose that on metal rims the wheels would have failed, but because of the flexible nature of wood rims they were plenty strong. However, the spokes made a lot of noise from rubbing together, causing me to resort to tying and soldering them. Once I'd done this my wheels lasted.
One other issue is that you cannot use normal brake pads--they will melt. The first time I tried wood rims I lost almost all my brake pads after only a two mile descent! That was a little alarming. At that time my solution was to use some vintage pads, I think they were either Universal or Weinmann, that had what looked like asbestos mixed in with the red rubber compound. Those worked. Nowadays, with carbon rims, which have the same problem, the solution is cork. Had I thought of this, I would have tried it.
Bob Schenker Oakland, CA
> Are they only for lightweight riders?
>
> Can they only take limited tyre pressures?
>
> Mainly for track use?
>
> Does the age of most surviving wooden rims now make them 'non-riders'?
>
> Thanks,
>
> Wyndham Pulman-Jones
> Girton, Cambs., UK.