Rear Wheel Alignment with Omar Spacer

[Mucmz]

So I have a question. I have a 1978 XS650 and put a front 19" spoke wheel in the rear using Omar's conversion kit. Now when I'm starting to align every and track the rear wheel, I noticed that the wheel is about a 1/4" offset to the left. Has anyone ran into that problem at all? Any suggestions?

 

[arcticXS]

If the chain run is straight, while your rim/tyre is 1/4" offset to the left, then a 1/4" spacer between sprocket and hub, and a 1/4" SHORTER spacer on the RH side should fix it. Or re-lace the wheel to move the rim 1/4" to the right. If the chain run is also incorrect, then a 1/4" longer spacer on the LH side, and a 1/4" shorter on the RH side will fix it.

 

[Mucmz]

Thank you arcticXS, that's what I thought and feared too. I didn't know if anyone else was having this problem or that the rear tire was just designed to be offset.

From what I can tell, the chain run is straight and even the rear brake support rod is straight too. So I'm wondering if re-lacing the rim would be the better path. See pictures.

 

[Bushyeyed1]

Did you follow these instructions from omar's?

"This kit allows you to use a 19" front wire or 19" cast wheel on the rear. This is a must on Specials with chopper-like 16" rear wheels. Kit also allows the use of a rear disc on the Standard 650s (but you'll need to steal all the brake components and swing arm from a Special to fit on a Standard)."

Also I doubt it matters but is it still that far offset with the left rear shock installed?

Just my two cents, but if your going to do a tracker then you might as well upgrade to the radian swing arm.

 

[arcticXS]

Yes, if the chain run is straight, the Omar's kit has correct dimensions. So re-lacing is the best way to fix the issue.
Also, I forgot to consider the rear brake, when suggesting to add a shim between sprocket and hub, and remove the same amount (1/4") from the RH side spacer. You would also have to add 1/4" spacers between caliper and caliper bracket, and use longer bolts.
If it was my bike, and it was otherwise ready, I'd have spacers made, so I could ride it asap. Then deal with re-lacing next winter.

 

[Mucmz]

Bushyeyed1, yeah I followed Omar's instructions to a T. I have a 78 Special, so I have the swing arm and rear disc brake setup already. I'm using a 19" wire wheel and followed his installation instruction.
BUT ...
I completely brain farted on the shock part. You make a good point. So I tried that and it pushed it over a bit more. I'm now only about a 1/16" off ... and that was just eyeballing it. I'll need to align everything and see how it looks. Thank you!

 

[Bushyeyed1]

@Mucmz I am glad that worked for you and trust me most of us have been called out over looking the little details on this forum. You should start a build thread of your bike so we can see the progress. I haven't seen too many people do an 19" rear rim, but it will look good on your tracker. I would probably get some stiffer shocks if you do plan on going off road though. I am interested in the fact that you have a rear caliper on a spoked rim in the rear. What type of rear hub did you use? Or is that just a front wheel with the Omar's kit installed? Gives me an idea for my next project.

 

[Ratranger]

Are the bearings relocated into the spacers? Or are they left in the stock location on the wheels?

I made my own spacers, with the bearings in the spacers, so I'm just curious.

 

[arcticXS]

Are the bearings relocated into the spacers? Or are they left in the stock location on the wheels?
I made my own spacers, with the bearings in the spacers, so I'm just curious.

That' neat, making your own spacers! Does the inside of your spacer go into the original bearing seat in the hub? Or do you use 3 bearings in total?
(My RD350A has 3 bearings, 2 in the hub and 1 in the sprocket carrier)

 

[Ratranger]

2 bearings, I made a rotor adapter for the other side. So bearings are out at the full width of the spacers, made a new inner spacer as well. This pic you can see the rotor adapter, and the far side the sprocket adapter.

 

[arcticXS]

Bushyeyed1, yeah I followed Omar's instructions to a T. I have a 78 Special, so I have the swing arm and rear disc brake setup already. I'm using a 19" wire wheel and followed his installation instruction.
BUT ...
I completely brain farted on the shock part. You make a good point. So I tried that and it pushed it over a bit more. I'm now only about a 1/16" off ... and that was just eyeballing it. I'll need to align everything and see how it looks. Thank you!

Hmm, you must have quite a bit of play in your swing arm bushings then. If the top of the wheel moved 5 mm to the right when fitting the left shock, there must be a couple mm slack in your pivot setup. Otherwise it is hard to see how it could move that much.

 

[arcticXS]

2 bearings, I made a rotor adapter for the other side. So bearings are out at the full width of the spacers, made a new inner spacer as well. This pic you can see the rotor adapter, and the far side the sprocket adapter.

Very neat!

 

[Mucmz]

@Mucmz I am glad that worked for you and trust me most of us have been called out over looking the little details on this forum. You should start a build thread of your bike so we can see the progress. I haven't seen too many people do an 19" rear rim, but it will look good on your tracker. I would probably get some stiffer shocks if you do plan on going off road though. I am interested in the fact that you have a rear caliper on a spoked rim in the rear. What type of rear hub did you use? Or is that just a front wheel with the Omar's kit installed? Gives me an idea for my next project.

@Bushyeyed1 sorry for being MIA. The bike is actually for my fiance, it will be her first bike. I like the look of the tracker, but want to stay with a lot of the original parts. So it will be a mash up between new meets old. Plus I'm a flat track racers, so I like the 19" look in the back. Here are a few pictures of how it looked and what it has gone through.....

 

[Mucmz]

Hmm, you must have quite a bit of play in your swing arm bushings then. If the top of the wheel moved 5 mm to the right when fitting the left shock, there must be a couple mm slack in your pivot setup. Otherwise it is hard to see how it could move that much.

The swing arm bushings are new and I went with the bearing style too. It was more on the lack of support for that one side, versus the other side. Once I added the other shock, it seemed to equalize both sides.

 

[Mucmz]

Are the bearings relocated into the spacers? Or are they left in the stock location on the wheels?

I made my own spacers, with the bearings in the spacers, so I'm just curious.
View attachment 163898

@Ratranger, it's been a while since I put them all together, but if my memory recalls, they use the bearings in the orginal hub. Then there are spacers for the axle on the hub spacers. Yours looks really good!

 

[Bushyeyed1]

You have definitely made it look really nice. What a lucky girl she must be having you build her a bike. I should tell my wife I’m building her one so I can get another project.