I hope this is not too far off-topic. It might be relevant to fears about the joint strength. Some Morgan tricycle owners seeking to iron out real or imagined design deficiencies make up a skinny propshaft that smooths out the dollops of torque from a vee twin engine. The racing engines are probably putting out some ninety brake horse. The front splined part is soft soldered into a tube on the original propshafts (Yes, I do mean soft solder!) but the modern version is glued together with a Loctite adhesive. When my brother queried the efficacy of this with the makers (Ciba-Geigy?) a few years ago, they patiently explained that Formula One half shafts were put together in the same way. Even if you have calves like a French poilu and thighs like a wrestler or a Portsmouth whore, I cannot believe you will exceed those applications. More opinions, please? Stuart Tallack who is working in Portsmouth next week and probably should have found a different metaphor.