Causes for rear tire to scrub driveshaft tube.

Hello,

I have recently got my wifes XJ750 running, and I am basically trying to complete as much work on it, and or figure out what parts we need to order before we put it in storage.

The rear tire scrubs the drive shaft tube, the rear tire size is 130 90 R16. Which I believe is correct as my XJ650 has the same size rear tire. What are some common issues that might cause this? I know the tube may be bent, but how can you tell.

Are there any spacers/collars or washers that could have been left out somewhere along the way to cause this condition?

 

A 120 rear is correct in both cases. Some 130's can fit without rubbing, but that's dependent on the sidewall profile and manufacturing tolerances.

 

130 is the correct tire for the 16” rim. Kmoe is thinking about the Seca with the 18”.
This is why you need to include your model in your question.
What brand and model of tire is this?

 

do you have the washer under the crown nut on the axle? it is a spacer.
https://www.partzilla.com/catalog/yamaha/motorcycle/1983/xj750k/rear-wheel

 

I just noticed you put R in the tire designation.
Is this a radial? That might be the issue.

 

so is this 1984 XJ750 Midnight Maxim in the 82 and 83 style of maxim
or is it a 1984 XJ750 Seca
Does the Canadain XJ750ML share the frame of the 900 too?

 

16” rim suggests it’s a Maxim

 

First time running since 1998??? Stop riding it and check rear brake immediately!!! https://xjbikes.com/forums/threads/...r-brake-bike-owners-please-take-a-look.15874/

 

or rim switch.
I am interested to see if the 84 midnight maxim is on a 900 style frame
if it is a 83 style frame this will be 2 bikes Canada got for more time than US
XJ1100 was a 2 year bike up there

 

The only 900s I know of were Secas; and all the Maxims from 750 right on down, had "cut down" frames for lower seat height and a more raked-out front end. Other than maybe the side stand switch, I don't think there's much in common between any 900 and any Maxim...

and Canada got a bunch of stuff after we couldn't any more, like the RD400LCs, 650 Seca...

 

The Canadian 1984 xj750 Maxim looks the same as the 83. Did the USA not get this in 84?

 

I haven’t been riding the 1984 xj750, i know about rear brake lining delamination on these bikes. it has a designation of a midnight model, but has some parts switch with a non midnight maxim. The frame is similar to xj650k that i also have, but there are some differences but do not know enough about the xj900 frame to say it’s similar to it. Both bikes have 16 inch rear rims, and both have radial tires, of same specification. I am going to check for obvious things before I tear to much apart. I will remove rear wheel from XJ650k and put it on the xj750 before I look into the differential. It may be the tire as some people have mentioned.

 

Are you sure they’re not just bias-belted?
I wasn’t aware radials are available in these sizes.
What brand/model tires do you have?

 

no we got the 700s

 

We got the XJ700 in 85 same time we got the 750-x

 

for 1984 we got the 600s

 

The tire is. Kendo Challenger 130 90 16. So far I don’t see any obvious parts missing. I have the axle with two spacers and nut.
Wheel bearings are notchy but they are are not allowing any side play.
Confused as hell.
I know I could probably add spacers behind the hub. But I don’t like not fixing the problem.
I tired to find a yahama part# on the rim but I couldn’t.

 

OK that is a bias-ply tire in the correct size so I think we can rule the actual tire out as the problem.
If you've removed the rear wheel and studied the schematic @XJ550H sent you, verified all the parts are there, in the correct order, then maybe it's a bent swing arm or something hokey with the final drive.
Are the 4 nuts securing the final drive to the drive shaft all tight?
Try mounting this wheel on your 650 and see if it rubs. If not you can rule out the wheel.

 

Was this because it was crashed? What has been swapped?

 

You can rule out the wheel without bothering - impossible for it to be bent all the way 'round. Are you sure no -one has fitted a final drive off another model, this would throw the wheel out?

 

i had a maxim with the same tire, same problem. there was a blob of weld at exactly the wrong place, a file fixed that right up.
that got me to a papers width clearance and a sanding disk/drill on the lip of the tire while it spun got 3mm clearance, that's all you need

 

and this seems to make the most sense. @Polock you have a gift of cutting through the BS.
A picture would have been good.

 

I will check for this weld bead. Is there a part# on the differential housing so I can differentiate the parts? I was talking to two previous owners they swear the bike was never crashed. Just said in the 90s it was cheaper to get used parts than buy new or have a garage rebuild the forks....

thanks for the help guys!

 

Just compare to your 650. They should look identical.

 

Well everything looks good with the differential. I see the weld joining the seams of differential tube.
Instead of grinding the weld, could I just Shim the rear wheel hub to the right to clearance the drive tube? I know I’d have to shim the wheel bearings by the same amount. How would this affect the handling of the bike? I have included crude drawings to show what I mean.