rear disc bikes

Do any of the shaft xj's have a rear disc brake? I'm thinking of converting over the winter rebuild, it'd be great if there were an easy swap for the wheel.

 

The 900 has Rear Disc.
The swing arm is altered to make the Rear Disc fit; plus an special Caliper Mount and Spacer to make it fit the Rear Wheel.

The Rear Wheel is different; too. With a special assembly for the Disc and a Damping section withh Pie Shaped Dampers is used.

 

Just Say No.........

 

Sounds like it'll be more trouble than it's worth.

 

Precisely.

 

Hi a newbie looking through forums....my 84' XJ 750 has rear disc but I'm downunder of course. Pic's of my bike in my gallery.

 

There are a few models with Rear Disc Brakes. But, the swap-over isn't easy.

You need to swap the whole rear end over including the swing arm and rear brake stay. That is going to mean a donor bike and some very technical modifications.

 

dont bother with the swing arm from the 750,it will not fit,its about 5mm too wide for the frame at the pivot, i've already tried it, i used the turbo drive shaft,turbo swing arm,750 diff, 750 rear wheel ,750 caliper and caliper mount with the 750 spacer and rear spindle, welded the bracket for the torque arm onto the swing arm, and it all lined up ok? had a donor 750 so for me anyway it was an obvious mod

 

When all's said and done.. the Simple Truth is that the Rear Drum stops better than the early yama disc setups.. sad ain't it?

 

If you do the maintenance and keep the Drum Clean, mount a set of new Shoes correctly ... so that the Brake material makes firm contact with the Drum upon applying the Brakes ... and, lube the Brake Shoe Activating Cam Pivot so that there isn't any drag AFTER the Brakes are applied ... you can adjust the Rear Drum Brakes to be very effective in slowing and stopping your XJ-Bike.

The Pivot Bushing on the Brake Lever very often dries out and rusts.
This causes the Brakes to drag after they are applied.
The fix is to remove the Arm ... push-in to remove the Shaft and either replace or refinish the Shoe-spreading Cam Shaft bushing.

I rolled-up a section of 600 Finishing Paper and twisted it into the Bushing.
I twisted it and removed the rust-likke build-up that binds the shaft.
The shaft I put in the Vice and "Shoe-shined" a new finish on the outside diameter of the machined suruface that floats in the Bushing.

After a cleaning and a refinishing of those two surfaces ... Rear Braking returned to Peak Performance.

Most importantly, is the positioning of the two Brake Shoes.
There is a Leading and a Trailing Shoe.
You MUST get the two shoes on with the right positioning of the Leading and trailing shoe ... or the Braking suffers greatly and they squeak to let you know they aren't on right.