One way a slightly loose wheel can be tightened is to replace the felloe with a new one. This brings up the condition discussed in question #3. New wood verses old wood and its elasticity. Another problem is that the tennons are usually oval because of age. They do not make good contact with the round new holes in the new felloe. The tennons also tend to snap off the ends of the old spokes because of the age of the wood and because of the stress put on them when the new felloe is fitted.

I have seen wheels with a thin shim between the felloe and metal rim. This works for a while but doesn't seem to last in a vehicle that is used on a lot of tours.

The worst way to attempt to tighten a wheel is to put shims between the spokes at the hub and fill the spaces with epoxy. It will not last for long. The wheel flexes and breaks the bond, or it comes loose from grease in the wood from the hub. It also forces the hub hole off center and causes the wheel to hop down the road. Therefore, I do not tighten wheels.