Rear Wheel Alignment Not Centered

[Dusty H.]

We recently acquired an old minibike. From a previous post, it seems as though it is some sort of Bird Engineering frame. I'm looking for advice on the rear wheel set-up. As you will see from the photos, the rear wheel greatly favors the clutch side of the frame, which makes the wheel off-center. Outside or moving the engine, are there any other options to help center the wheel (different style wheel/sprocket, etc)?

While we're at it, the previous owner used locking collars to hold the wheel in place on the shaft. Is that a good method or would the use of axle spacers be preferred?

Thanks,

Dusty

 

[nightgrider]

Adding a jackshaft is the best way to center up the rear wheel and leave the engine mounting alone. Another option would be to use a drum sprocket or space the current sprocket to center up the wheel. That would allow you to center up the wheel but not modify the frame.

For the axel I'd use spacers.

 

[Dusty H.]

This what you mean by a drum sprocket?

 

[Dusty H.]

The current wheel doesn't have much to allow for spacing. To make sure I'm following, essentially use a wheel similar to this, but add spacers as need to the bolts?

 

[nightgrider]

This what you mean by a drum sprocket?

Yes that is a drum sprocket.

You could get a wheel like that or another wheel with a hub that would allow for sprocket spacing.

 

[sparkwizard]

For starters, try loosening the setscrews on those locking collars, centering the wheel, and then tighten the set screws.

 

[Dusty H.]

Yes that is a drum sprocket.

You could get a wheel like that or another wheel with a hub that would allow for sprocket spacing.

Would you be kind enough to link me to what you have in mind?

 

[Dusty H.]

For starters, try loosening the setscrews on those locking collars, centering the wheel, and then tighten the set screws.

I can do that, but the sprockets won’t be aligned at all.

 

[Strigoi]

For starters, try loosening the setscrews on those locking collars, centering the wheel, and then tighten the set screws.

Those are fine for mocking up a setup and figuring out what spacers you need. They're not OK to ride with. That wasn't clarified...

I use those for that exact reason and they work great. Not a chance in hell I'd ride with them installed instead of proper spacers.

 

[nightgrider]

Would you be kind enough to link me to what you have in mind?

I could throw links out there, but i don't know exactly how much space you have to play with on your frame. It would just be blind guessing. You first need to take measurements of your frame and find out what how much space would be on each side if the wheel is centered. Then you'll have to take measurements to see how much the sprocket would need to be spaced to make it align with the clutch. Then you can go shopping for what wheels and hubs are available in the size you need. Looking at the scrub brake set up you're kind of locked in at the current wheel and tire diameter on the bike now.

 

[minibikin']

Forget aligning the sprocket at this point. Center the wheel in the frame. Take measurements of the spacer you need on each side from the face of the wheel bearing to the inside of the axle bracket. You can buy them in most common lengths or cut your own out of 5/8: ID tubing. Now you can use washers and longer bolts to space the sprocket off of the wheel hub and get it aligned with the clutch. Once you get it spaced correctly measure the stack of washers and cut an appropriate length spacer for each sprocket bolt.

 

[hermans13]

I agree with minibikin, the wheel must be centered first. He gave you a lot of good advise on how to get it done. If you don't have 5/8" tubing, you can buy a length at Home Depot.

 

[minibikin']

OH one more helpful hint I've learned with chain alignment. A magnetic laser is The gato's bumbum...

 

[Bird Brain]

This is the rear rim/tire dimensions from my ole Bird should be similar. 4.10/3.50-6. The rim center bearing hub is 4.750" in width no bearings installed. The frames inside width for the rim is 5.875". You would need to make up (2qty.) 1/2" length x 5/8" i.d. spacers. That leaves you with an 1/8" clearance for assembly torque up overall. I can give you the rims offset dimensions if you need them if it'l help any with your search.

 

[Bird Brain]

Here is the offsets. Hope it might help with some clarity.

 

[minibikin']

This is the rear rim/tire dimensions from my ole Bird should be similar. 4.10/3.50-6. The rim center bearing hub is 4.750" in width no bearings installed. The frames inside width for the rim is 5.875". You would need to make up (2qty.) 1/2" length x 5/8" i.d. spacers. That leaves you with an 1/8" clearance for assembly torque up overall. I can give you the rims offset dimensions if you need them if it'l help any with your search.

Thats great info. The only issue is him not having the original wheel . It is much narrower bearing to bearing than the stock wheel.