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Old 09-04-2009, 12:32 PM   #223
Beastly Adventurer
Joined: Mar 2008
Location: Penticton, BC
Oddometer: 1,624
Originally Posted by itsatdm
Not being smart, serious question, what are you going to measure it against? I can assume if the bearings are bottomed out and a circlip to hold them in, I would expect little or no tolerance between the two. Do you know how long the spacer should be? The axle is torqued to 74 lb. which I would think bring the spacer into contact with the bearings, how much is too much pressure or should there be none at all?
Hey, don't worry. This is ADV, and nobody should be such a tightwad as to take offense that easily!

The length of the spacer as prescribed by Woody:
here's where it gets interesting,,,there are two basic approaches to wheel-bearing set-ups.,,,i'll call them:

type A,, probably the most common,,,uses precisely machined lateral flanges on the ID of the hub to locate the inner spacer is used to prevent crush when tightening all the components /spacers on the axle... this spacer needs to be minimally .010''+.002-.000/steel or .020'' +.003-.000/aluminum to be effective.... so the hub essentially has a little bit of lateral float buildt in... a simple elegant fairly bullet-proof technique which fails only when :

a,,,the manufacturer uses too soft axle spacer BWOE KTM several years ago on the rear dirt bikes,,too much torque would crush them resulting in many blown up rear hubs

b,,someone specs a spacer the same size or smaller than the inner lip dimension.

type B,,used by Kawasaki,Honda,BmW,Triumph etc, uses some means of retaining one bearing on one side [usually the side where the disc brake is on. ie to make sure the wheel consistently is spaced /aligned properly with the disc],,Kawasaki,KTM and BMW routinely use a circlip to retain that bearing in place,,,honda and triumph usually use a nut to hold it.,,,what usually happens next is that on the other side the bore in the hub often doesn't have an inner lip or the lip is usually bored far deeper than the width of the inner spacer...VOILA you have no worries about proper inner axle spacer dimensions because the bearing should self adjust....

The clamping force of the nut is to keep the axle positioned in the swingarm (and obviously to ensure the nut doesn't back off). It is not to 'preload' the bearing assemblies. Only one bearing is held in by a circlip, so the appropriate spacer length is less of an issue than the depth the second bearing is seated to.

Bayner screwed with this post 09-13-2009 at 12:48 PM
Bayner is online now   Reply With Quote