Is the front disc on a 72 XS supposed to be "loose"

[the_nutt]

Just picked up a 72 XS650. This is my first Yamaha, I've only had Honda CB's until now. I noticed the front rotor rotates independently of the wheel, about 1/4" in either direction. The bolts that mount the disc are tight, and it does not move side to side. I read through my entire manual, and tried searching, but came up empty. Is this part of the design? If so... why?


Thanks,

C

 

[yamasarus]

There are bearings in the disc carrier that have failed. Not uncommon. There was a tech bulletin on it in 1972.

 

[the_nutt]

There are bearings in the disc carrier that have failed. Not uncommon. There was a tech bulletin on it in 1972.

Thanks for the reply. I'll go on the hunt for a replacement.

 

[the_nutt]

Bringing this back from the dead, WITH PHOTOS!

I've never experienced a motorcycle with a rotor connected to the fork leg. This is new to me. From the looks of this (see photos) I think the rotor's slots are "wallered" out. I can't find a '72 rotor anywhere... what are my options? I'm ok with aftermarket, but don't have an insane (Brembo) budget. Help?

If a new rotor isn't my issue, where exactly are the bearings in the disc carrier located?

 

[XSLeo]

If you look at the parts fiche at a seller like boats.net you will find the there are two rubber parts that fit in the slots in the rotor and engage the matching nubs on the hub.
Yours are missing.
Leo

 

[angus67]

wouldn't a later front rim with bolt on disk go rite on? They only did that for 72, I think.
Forks are the same for a few years.
Some one around here has to have a later rim they could selll you.

 

[the_nutt]

If you look at the parts fiche at a seller like boats.net you will find the there are two rubber parts that fit in the slots in the rotor and engage the matching nubs on the hub.
Yours are missing.
Leo

Ah I see. Thanks for this ill try and track some down. Still seems like a ridiculous design...

wouldn't a later front rim with bolt on disk go rite on? They only did that for 72, I think.
Forks are the same for a few years.
Some one around here has to have a later rim they could selll you.

I think I'd definitely rather run a standard wheel with the rotor attached. I'll shop for this as well.

 

[jayel]

Ah I see. Thanks for this ill try and track some down. Still seems like a ridiculous design...


I think I'd definitely rather run a standard wheel with the rotor attached. I'll shop for this as well.

you are not the first to fight out this problem pretty sure there are a few other threads that hash out the wondrous 72 brake

 

[cra-z1]

On mine I located some rubber sheet with a semi-hard durometer (hardness) and cut them to fit. Measure the amount of rotation and this is the thickness you need. Divide it in half and this would be the rubber thickness for each side. Locate a company who sells sheet rubber. They could probably help. As for the bearing I seem to recall it may be the same bearing as used on the cam which can be purchased from mikes. It's been a while since I had the wheel apart. I would rebuild it as close as possible to stock. I do have an extra disc if needed. It was a unique design to the 72 so it would hurt value if changed. I think the 72 is the best looking of the early XS650's. Good luck with your project. Now it's coming back take a look at this link.http://xs650forum.proboards.com/thread/2938

 

[gggGary]

The rotor also unbolts from the hub so you could swap rotors.
Somewhere in here I blew up pics and dimensioned the rubber parts.

 

[gggGary]

Here's the thread.
http://www.xs650.com/forum/showthread.php?t=16441

 

[the_nutt]

Thanks for all the info and measurements. I think I'm just going to silicone it for the time being, and do a modern fork conversion sooner than I thought...

 

[gggGary]

IIWM I'd cut up any old piece of rubber; from an inner tube patch kit or a mud flap comes to mind. Silicone is just too soft and might end up in the wrong place in a hurry. (front brake....)

 

[the_nutt]

IIWM I'd cut up any old piece of rubber; from an inner tube patch kit or a mud flap comes to mind. Silicone is just too soft and might end up in the wrong place in a hurry. (front brake....)

That makes more sense. I was thinking silicone bc that's what Mike's suggests to people looking for the original Yamaha part. Hard rubber it is.