Hi Folks! I've come across this issue with a few customers' bikes recently and I'm not aware of it being mentioned before. To cut to the chase, it is important, when tightening the rear wheel spindle, to tighten the left hand side first. In the UK we also refer to the left side as the kerbside. So, to avoid any confusion, I'm talking about the side where your left leg is. This is the case for the later, full width hub and the earlier crinkle hub. I'm not sure about the Ariel hub but I'm guessing that's the same. The reason for this is because the rear spindle is in two parts, the left part being the 'dummy spindle'. The dummy spindle has flats on it for location into the swinging arm and, if you look closely, you'll see that the flats are shallower than the slot in the swinging arm. So, when the left side is tightened the dummy spindle and the swinging arm are solidly locked together against the shoulder of the dummy spindle. If the flats were as deep as the swinging arm slot it would be impossible to tighten the left side because the wheel nut would be tightening against the ends of the flats instead of against the swinging arm, so the assembly would be able to slide forwards and backwards in the swinging arm slot, and to prevent this the stability of the rear wheel would be relying entirely on the torque arm... which is obviously wrong. The crinkle hub type wheel (Q/D) is great because you can fit the sprocket and brake independently of the rest of the wheel (hence Q/D) and check for free rotation, and endfloat of which there should be virtually none. The FWH needs to be installed as a complete unit (PITA) but the same principle applies. After tightening the left side, the components in the main part of the wheel, and any spacers, are designed to take up the space between the dummy spindle and the inside edge of the right side of the swinging arm. So, when the wheel spindle on the right hand side is tightened, all the spacers and bearings are locked against the dummy spindle in a 'sandwich' in between the swinging arm legs. The issues i've come across, particularly bearings coming loose, have been caused by the wheel floating from side to side. Logically, if the left side isn't tightened first, the right side hasn't got a solid mount to pull against so the whole assembly is loose and falls victim to the stresses and strains when riding the bike, and things come loose.
