Took the bike to get a new rear tyre yesterday, got the wheel off and discovered the drive belt side wheel bearing had a load of play on it, and felt rough, my local shop is pretty good and well stocked, so he measures the bearing and the OD and ID were pretty standard, he has a bearing to fit, (now some of you already know where this is heading :s). so we knocked out the old bearing to discover that the replacement was 3mm thinner than the original, so we knocked up a 3mm mild steel spacer to take up the end play put the spacer on the inside and fitted the new bearing. Perfect - good job! Heading home I realised I had no ABS, so has a hunt aound the internet and discovered the following: The ABS bearing has a magnetic encoder inside of it to trigger the wheel speed sensor on the special spacer that ABS bikes have. You can use ABS bearings (assuming the size is right) on a non-ABS bike, but not the other way around (unless you want to throw an ABS warning). This bike has only done 8700 miles, the bearing was shot, although there was no sign or noise other than a bit of a wobble going a bend at 80 mph, now its not got a wobble. I guess I will fit a set of original bearings, however if your Road King wobbles get the rear bearings checked, could not tell till we had it on the wheel balancer.