17 inch rear wheel

[Speakas]

Hello everyone,

I've been slowly building my 79 special over the past 2 years and need to fit a rear wheel.

I want to run a 17 inch wheel, ideally with a 160 tire, though I am willing to settle with a 150.
My swingarm has been extended by about 2.5inches to allow more clearance.

Problem is, clearance with the sprocket. I currently have a cfmoto 17x4.5 with a 160/60 mounted on and it looks like even with a smaller sprocket I'm going to have massive fitment issues with chain that might interfere with the shocks. I know I will need to offset the front sprocket to clear the tire. See attached pics.

I don't think the cfmoto will fit, so need to look for something else that will. The cfmoto conveniently had a matching axle diameter. I know I may need to get a machined sleeve to suit for different wheels but I am unsure what would be the best fit.

Anyone got any experience mounting wider rims and wheels? I know it's common with the hardtail guys so would like some advice.

 

[Ratranger]

I used a kz750b rear hub, which also gives a cush drive, laced to a 17x4.25 rim and a 150x70r17 shinko 705. I had to space the rear sprocket 3/8 of an inch and it lined up with a 520 front sprocket. I'm running monoshock so no clue on shock clearance.

 

[Speakas]

Cheers for the info.

I am going to look into r3 or ninja 300 wheels. The rear rim is 4 inches instead of 4.5 which hopefully will give me more clearance for chain and sprocket with a more recessed cush drive. Downside would be the need to fit the wheel to the xs650 axle.

I will have to compromise and run a 150 tyre but I will see how the 160 fits on it since it still does have some space.

I wish I did run a spoked wheel instead of mag, but the options were quite cost prohibitive especially with the gsxr front end I have installed. Maybe in the future.

 

[Ratranger]

Might check a bandit 400 rear wheel, I think it's 17x4. Gs500 is a bit too skinny for what you want.

Yeah if you run a front end with a 25mm axle it really limits options.

 

[gggGary]

For reference GS500 mounted on Radian arm. No sprocket offset needed.

I'll check but think that's a 140 tire 150 shouldn't be a problem.
Final shock selection hasn't been made.

 

[Speakas]

@gggGarry the gs500 wheel actually looks quite suitable. the rear sprocket seem small enough to keep the final ratio close to stock too. Do you know what the axle diameter is?

The bandit 400 looks like it has the same axle diameter as the xs650..20mm?

The bandit looks like its harder for me to source here in Perth, Australia. but if its almost a bolt on fit it could be worthwhile getting one in from somewhere.
The gs500 is littered everywhere though, wishful thinking its a bolt on

 

[gggGary]

I'll have to recheck but think GS axle is smaller, was a bolt on to the RADIAN swing arm...
Had to custom order an aluminum sprocket and do a little machining, the sprocket nuts were hitting the swing arm, too noisy
The GS500 uses 520 sprockets, the "fix" was to machine an 1/8" deep ring in the 530 sprocket from rebel gears so the nuts thread further on to the studs.

 

[Speakas]

I just picked up an R3 wheel, from rough measurements sprocket clearance is much better. axle diameter is however at about 17mm.
Im no machinist so wondering if anyones got experience fitting a smaller diameter wheel hub to a larger axle diameter?

If im not mistaken, I need to find a wheel bearing that fits the R3 outer bearing diameter (40mm) and the xs650 inner bearing diameter (20mm) and with the same width as the r3 bearings. and machine a custome sleeve between the left and right bearings.

 

[Speakas]

Reviving this old thread.

So I sent it to the local custom bike shop to get the wheel fitted and they opted to fit the cfmoto wheel with the sprocket offset inwards to line up. There is also the brake caliper bracket which also acts as a spacer

Now I noticed the tyre is much closer to touching the swingarm on the right (brake side) than on the left. And my eye ball measurements tell me that the wheel may not be centreline. Kind of looks like it's too far left but going right isn't going to work since it's more or less going to touch the swing arm.

I've got a 130 tyre on the 17 inch fitted right now. The stock tyre I had was also a 130 on a 16 inch wheel. The strange thing is I remember it was also much closer to the swingarm on the right side on the stock setup as well. Though my goal was to run a wider tyre, I don't think I'd be able to fit more than a 130 even with the extended swingarm.

Can someone confirm if the stock setup looked off-centre as well with the edge of the tyre closer to the right side of the swingarm?

 

[Speakas]

Might also ask how much of a worry it is if the rear wheel isn't perfectly centreline with the frame and front wheel as well? I imagine handling might be weird..

 

[gggGary]

Sprocket off set inward? Chain hitting tire is often an issue with wide tires, o-ring chains.

 

[Speakas]

Sprocket off set inward? Chain hitting tire is often an issue with wide tires, o-ring chains.

They made an adaptor as the sprocket carrier was too far outwards. I haven't tested a chain on it yet but it looks like it has a clear path and won't hit the tire.

 

[Speakas]

Some pics, by measuring the swing arm gap between the adjusters, I found it at 26.5cm, which would mean the centre of wheel should be 13.25cm, I think mines off by about 0.5cm which is probably okay. The question is the swingarm centre actually centre to the frame?

 

[gggGary]

Cameras lie, but your rear sprocket looks like it's too far in compared to the front in pic #3.

Need straight edges on both sprockets to check. that's not super easy to do..... you gotta anyways.

 

[Speakas]

Oh

Cameras lie, but your rear sprocket looks like it's too far in compared to the front in pic #3.
View attachment 230375
Need straight edges on both sprockets to check. that's not super easy to do..... you gotta anyways.

Forgot to mention the front is currently a 530 sprocket.and rear is 520. I'll find a straight edge and upload another picture but I'm fairly confident they line up. Just worried about wheel Centreline lining up with frame and front wheel.

Side note, how do I remove the front sprocket with no way to lock it

 

[gggGary]

In gear and a battery or air impact usually works.... 36mm
other wise a chain and rear brake or a chunk of wood through the spokes.

 

[gggGary]

Sprocket studs/nuts to swing arm clearance may be an issue also.
How many teeth is that rear sprocket? It looks big.

 

[gggGary]

So I sent it to the local custom bike shop to get the wheel fitted

What are the odds?
jus say'n

 

[Speakas]

Th

What are the odds?
jus say'n

They are usually reputable in the custom bike scene but mistakes or oversights do happen.
It's a 39t sprocket, not ideal but should be okay for the street. The studs dont hit the swingarm but there is enough clearance for it.
I'll try the in gear and impact but it seems to be on tight.. once I've got that sorted I should be able to take it for a slow spin down the street. Fingers crossed wheel centreline alignment isn't an issue

 

[Adamc]

Oh
Forgot to mention the front is currently a 530 sprocket.and rear is 520. I'll find a straight edge and upload another picture but I'm fairly confident they line up. Just worried about wheel Centreline lining up with frame and front wheel.

Side note, how do I remove the front sprocket with no way to lock it

Buy, borrow or steal a Milwaukee big boy impact driver; comes off in a jiffy!