circa 1980 XS650 front wheel spacer

[jellywrestler]

hi folks
i've got a yamaha mag front wheel on my chopper and i notice that the front wheel spacer seems to be a few thousandths of an inch longer than the seating points for the bearings. this would mean that with the spacer in one, or both bearings aren't going to drive fully home to the shoulder inside the wheel, is this correct?
i also brought a genuine
Flange, Spacer

146-25315-00-00

as mine was missing, now this would appear to hold the front wheel spacer in the centre of the wheel so when the axle is removed the spacer doesn't fall away into the hub, the spacer is smaller than the bearing shoulder, whereas for the rear it is about the right size, now i'm not sure what model my front wheel is but this part number fits about 100 different yamahas, so assume it is right.

can anyone tell me whther the first part about spacer length sounds right? what would be really good is if someone could run a set of verniers over one and tell me the correct length as it could be a fabricated one (although it looks to be of the same material and turning quality as the rear one).
thanks from new zealand
Graeme

 

[jellywrestler]

just bumping this back into the eye folks thanks

 

[arcticXS]

The spacer needs to be slightly longer than the distance between bearing seats, to ensure the bearings are not binding. 0.10 mm should be sufficient. I could be argued that the spacer only needs to be exactly the same length as the distance between bearing seats in the hub, but due to manufacturing tolerances, it is safer to have it slightly longer. In any case, make sure the bearing seats are 100% clean when mounting your new bearings. Any particles or dirt will easily add 0.10 mm to the spacing of the bearings, and then they will bind when you tighten the wheel axle (bolt)