The yoke offsets are important because too much offset reduces the trail. It causes the bike to understeer, and can cause a mishandle - the bike can stand-up under brakes and suddenly turn in the wrong direction. The trail on the steering is a combination of rake, wheel size and yoke offset. I think a Commando would have about 26 degree rake, and would use yokes with less offset than those from a featherbed. The worst yokes would be those from a Garden Gate Norton. They have a lot of offset. For a bike which is going to be ridden fast - nearly 100mm of trail with 26 degree rake and 18 inch wheels is good - but not on a two-stroke with a peaky power-band. I think the rake on a featherbed is usually 24.5 degrees, with 19 inch wheels. With 18 inch wheels, they are useless. Less trail makes the bike tend to understeer - with more trail it is possible to gas the bike harder and earlier in corners. The weight distribution then becomes more important - it needs to be well forward.
