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xr650r cast wheels (writeup)

89473 Views 119 Replies 48 Participants Last post by  Franky450
I owe a lot to Kubiak for his write up for doing cast wheels for a sumo- I would like to ask questions while working on mine as well as adding to the collective knowledge of the group. so here are some prelim. pics of my rear wheel. The wheels comes off a '94 CBR600F2 and is going on a '00 XR650R.

The questions, on the drive side...
How much material is taken off past the plane where the sprocket mounts? I am guessing this is where i will make up a good chunk of the sprocket-to disc separation. (I'll post a pic with measurements)

Are the studs threaded in or press fit in? I read that you need to heat them and pull them out- but it was unclear if they were threaded in.

How do you get the cush drive concentric to the wheel? the 3rd bearing is going to be removed so you can't use the axle...??? i would think minor differences are going to make the sprockets and chain wear faster, major differences could cause a chain jump...

Questions on the Disc Side...
Removing all noted 'lips' should get the wheel all the way over to the disc side.

Do I need to remove the lip around that outer bearing race?

The bolts that hold the disc on have some non-threaded thickness. do i need to cut into this to move the wheel over some more?

:thumbup:
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you got the right idea.the studs are threaded in,i heated the hub and used vise grips to get them out.i dont have my 4.5 wheel anymore that i machined and the xr 650r might be a little different but heres what i can help with.first shave off a 1/4 inch off the brake rotor side lip then shave off the bearing seal lip flush with the bearing.then the rotor bolts have a shoulder on them and you can counter sink the bolt holes so the shoulder seats all the way down.i used a drill bit to do it.then that should be it for the rotor side.now put the wheel into the swingarm with the brake caliper arm in place and a washer between the wheel and the brake bracket.then see how much you need to take off the face of the cushdrive so the sprocket aligns where the original sprocket was.mine was just a feww mms from the side of the swingarm.then have the cushdrive milled off,then weld the cushdrive to the wheel.when you weld it make sure you spin the wheel to make sure the cushdrive is straight then weld it up.i didnt weld all the way around but you can if you want.then cut a spacer to take up the room between the swingarm and the sprocket.i used bolts for the sprocket that i grinded the head down till it fit with clearance from the swingarm.its pretty tight but i actually cut a little off the lip of the swingarm to clear the bolt heads.you will see what i mean when you place it in there.hope this helps.let me know if you have anymore questions.thanks!
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Sorry guys for the death of this thread for a month, but had some travelling to do... so anyways, the pictures that i have promised with some measurements.

I have to get the disc and drive into the 5.804" spacing
The swing arm has 6.648" spacing, this number will give me a ballpark on what kind of spacers i will need. It seems the best way to get exact will be fitting it will some washers.
Measuring from the disc side, I can remove 0.26" at minimum, I'll likely to remove more, to try to get to the stock sprocket-disc spacing.
The cush drive has a bunch of material that can be removed, and also, i noticed that the center has to be machined so that i can get the sprocket side bearing out if it ever needs to be replaced...
Keep updating this thread with pics

Please keep updating with pics. It is a great help for us!:clap:
remember when you are measuring, to measure the space between the brake side swingarm and the chain line, not the swingarm side to side measurement only because the wheel will have to be centered between the chain and the right side of the swingarm.hope this helps some!
Also remember to cut down the spacer that goes inbetween the rim and cushdrive. You need this to keep the side loads off the bearings.

R
Hey g1k, i'm not sure if i'm following. the order as i understand it would be (left to right)

swing arm, spacer (size TBD), bearing in rim, spacer in rim, bearing in rim, spacer (size TBD), caliper, swingarm.

there is another bearing and spacer in the cush drive that will be lost because of the machining. is this the spacer you are talking about?

thanks for the feedback guys...
Oh yeah- a BBQ grill works great for heating this thing up to pull the threaded studs out. I cranked up the grill to high, left the piece in there for 15 minutes. Pulled it out with some pliers. I was trying to figure out what the best way to hold this thing- worked out just stepping on it- and some vice-grips grabbing the studs. When you do this- you can tell when the piece has cooled too much, the studs get very hard to turn. Drop it back in the grill and walk away for 10 minutes... It took me 4-6 heating-turning cycles to get them all out... You will melt the bottom of your shoes, and be sure to knock the cush drive bearing out before you put in in the grill... I cleaned the thing with some degreaser first, the washed it thoroughly - didn't want to get a fire going ya know....
Here's the numbers -
Total width of the F2 wheel, no cush, to the un-machined face of the disc-to-rim mounting plane.
5.387

By milling the plane the disc mount's to i can get at minimum- maybe a bit more... (see pic in post #5)
-0.26" (-0.30 works)

So that puts me at
5.127"

This allow me 0.677" for the cush drive to keep the same spacing. I will try to gain a bit more on the disc side, machining as deep as I can. This will allow as much material left on the cush drive. I think the 0.677 is getting very close to the gussets that are cast into the cush. I would like to keep as much material around the sprocket bolts as possible. I'll get a better picture of this when I get home tonight. (look close and you can see the pencil marks. - there are 2 those are the tolerance marks +-0.025)
My .02. We measured sprocket mounting face to rotor mounting face on my

F3 rim and the stock rim, then machined the F3 rim so it matched the dirt rim.

We kept the distances relative to the center line of the dirt wheel, while keeping

in mind the dirt wheel can be offset. The we made spacers to put the CBR wheel in the

correct spot. We drilled and tapped the

cush drive to accept low head allen screws to mount the sprocket.

http://www.mcmaster.com/ catalog page 2977

We drilled/tapped and fitted inserts on the rotor side so that I could use the bolts

from the XR to mount the rotor on the CBR rim.

Biggest difference between mine and yours is we kept the cush drive operable.

I let you know how that turns out. Hope the rotor/sprocket mounting helps.
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Help

Could someone post pics for a cbr wheel mod for a XR650L Please:clap:
well, if anyone has been watching this thread- you may have noticed the utter stop to it. i am stuck, anyone in Las Vegas know of a good shop to take the wheel to? it kindda sucks, only 100yds away in the same building im sitting right now there is a brand new lathe and mill... but no... no outside work, and you have to be 'authorized' to do work... that's all for now, let me know if anyone is knows of a shop
here are some pics of the f3 front wheel and cbr 900rr 5.5 rear with the cushdrive cut and welded direct to the hub.
i used a rear wheel from a kawasaki kr1250,which has only a 1mm difference between the disc face and sprocket face compared to the standard yz wheel.By machining lip off sprocket carrier i was able to retain that as well,also had wheel machined to take yz bearings and rear disc same diameter as yz item,with new spacers it all fits and lines up perfectly.i wouldn,t have thought an xr was much different in terms of dimensions
kubiak in the ver last reply you show a pic of the rear rotor with the machined surfaces. Thos bolts that are holding the rotr, Are they the stock bolts with the "shoulder" on them?

This is where I'm having a problem, my bolts are bottoming out from the shoulder onto the hub before the rotor is even becoming tight. I though maybe some shims would work, but that way you did it looks very professional.
on on wheel i had the shoulder lathed off shorter then the last two wheels i just countersunk the holes with a drill bit till the bolts seated all the way.hope this helps!
RE: cast wheels

This is a great thread for anyone interested in adapting cast wheels;I'm following along,too,because I plan to do a similar mod for my CR500....

Thanks guys.

Sam in IN
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