Good Heart, Bad Intentions: another build thread

That's a mad mad project to be sure... and I fully endorse it!

 

Since I finally have the Honda running reliably, I've been able to take a little time to get back to work on some misc. XS projects... First up is the rear wheel. Just to re-cap, here is the (thus far) current set-up:





The hub is a stock XS650 front, with Omar's conversion adapter on the the drive-side and my own Aprillia/Brembo brake adapter dealie on the brake side.

Here is the new hub assembly hanging on the axle:



To make the new assembly fit, I need to make up new outboard bearing spacers on both sides, and modify the brake hanger. The new hub is 5/8" wider between the flanges; this makes for a better spoke angle (theoretically stiffer wheel) and puts the bearings further outboard. Also, with the Omar's kit, the stock front bearings are poorly-spec'd... The front hub uses a smaller bearing on the left side to make room for the speedo drive; the Omar's kit flips the hub so the small bearing is on the right/brake side, then stacks an additional large(r) bearing on the drive side. In my new assembly, I've bored out both sides for larger rear bearings. I kept the left side of the hub on the left, because now the cush-drive sprocket-carrier sits into the recess where the speedo drive used to sit. Clear as mud, right?

I made the entire cush-drive assembly 5/16" narrower than the Omar's spacer, so the chainline relative to the hub center would be consistent. The new drive-side outboard spacer is just a simple spool. I hung the hub on the centerline, checked the chain for parallel to the the centerline, and measured the spacer length in place... cut the spool a touch long, then fit, file, sand. fit, file, etc. until the chainline is perfect.



I'd like to replace the straight spool with a a tapered/stepped one that presents more surface area to swingarm and leaves less of a gap where it enters the sprocket carrier, but it'll do.

The brake side is trickier. Unlike the drive side, I couldn't simply make the brake assembly 5/16" narrower to accommodate the 5/8" widening of the hub center; the rotor needs to stay a minimum distance away from the spoke flange to maintain spoke-to-caliper clearance. Also, the outboard spacer I made to fit the Aprillia brake is a beast; stepped with three different outside diameters to center the caliper hanger, clamp the inner bearing race, and clamp the whole assembly. Ultimately, the whole brake assembly needed to move over, with the caliper bracket being clearance to fit the swingarm better. Since the wheel bearing has also moved outboard relative to the brake, spacer material needs to be removed from both sides of the caliper bracket... In the end, I removed 5/16" outboard and 3/8" inboard... the bearing is now 15/16" further outboard, the rotor-to-hanger clearance is unchanged, and the caliper is 5/16" further outboard.





The trick is to keep the rotor centered in the caliper, 'cause there's really no wiggle-room...



Ideally, I'd like to shave .030" off the inside face of the caliper mounting tabs to get the caliper a smidge inboard... The Brembo caliper supports the pad very well, but leaves just enough slot for the rotor to ride in!