Tire Rubbing Chain

Kathos

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So I'm about ready to ride this season. I set my x-ring chain tension (1 1/2" of play all the way up to all the way down) with my weight on the suspension. I set the rear alignment by using a straight edge from the rear tire to the front tire measuring the gap. I noticed that I rub the chain with the rear tire aligned. I read up that the o-ring chains cause this issue because they are thicker. So to fix it, I would say I could take the rear wheel slightly out of alignment to miss the chain. The problem with this is its so close to the brake arm that I have practically no room. The tire also seems untrue enough that it will either rub the brake arm, the chain, or potentially both at some points.
Its a 104 link chain and I am at the ~4th alignment notch on both sides.
Tire is the standard 130/90R16.
Is it dangerous to have chain X's on your tire as long as they aren't actually digging into the sidewall?
 
I take it you have a Special? Do you have the right torque arm? The Special torque arm is dimpled to provide tire clearance .....

SpecialTorqueArm.jpg
 
Nah, dirt bikes commonly have chain scalloped rims! Used supermoto rear rims always seem to have chain marks. Long as there is clearance when its not flopping around you should be OK
 
5-twins - Yes I have the special, I will check the torque arm. However, the torque arm is not a concern when my alignment is correct (according to spacing to my front tire), only time its in the way is when I am adjusting my tire to prevent contact with the chain. Is it standard practice to mis-alight the back tire to avoid chain contact?
gggGary- The chain can be seen rubbing when I roll it back and forward. Not the entire time, but in a certain section of my tire, say, less than 1/4 of a rotation.
 
No, it's not common for it to rub, unless maybe you mount a larger than stock tire, but you haven't. Is the wheel spoked? If it is and it is only contacting the chain during part of a revolution, maybe it's not true. Another possibility could be the tire mounting. Maybe it's not fully seated and "popped out" on the rim.
 
I definetly do not have a notch in my transfer arm. Correct me if im wrong but it looks like that specific arm is for models that have rear wheels with drum brakes.
Non the less, you are probably right that my tire on my mag wheel isnt true. That or the entire wheel isnt perfectly true because I can see the gap between the chain and tire change enough to rub and not rub when I spin it.
The tire is a duro 130/90/16
 
So you're saying you have a disc mag? Yes, the torque arm I showed is for the drum rear 16" wheels. The arm for the 18" drum rears doesn't have (or need) the dimple in it for tire clearance.

Take a close look at your tire where the bead meets the rim, all the way around on both sides. You should see a thin bead of rubber, sometimes a double bead, right next to the rim. This is an indicator to show you the bead has popped out and fully seated.

BeadSeat.jpg
 
Yes I have disc mags. I will double check the bead when I get home. The tire tread is worn enough where if I was to have to mess with it, I would just mount a new tire. Is there a tire that is known to run a bit smaller or should I just look at a120/90 tire.
In my head, the root cause of the problem is the new x-ring chain which runs wider. That plus the lack of chain stretch requires my wheel to move forward.
If I am under proper alignment, and the tire hits the chain, either the tire sidewall needs moved to the right, or the chain to the left. Either that or my swingarm isn't straight which causing clearance problems when keeping my wheel aligned. But the swing arm doesn't have play so I think I can rule that out.
 
You write that the tire contacts the chain on only 1/4" of its diameter. That's enough to tell you that chain width isn't the cause of the problem and neither is forward position of the wheel or wheel alignment. If any of those caused a clearance problem you'd have contact all the way around the tire. Put the wheel and tire on a truing stand and check for runout.

To check alignment, measure from wheel axle to swing arm axle. 1.5" laden play in the chain is about .5" too much.
 
Griz, I misspoke when I was explaining. The tire did contact the chain the entire time when the rear tire was aligned. When I tried to mis-align to avoid the chain, it contacted only a small patch of tire.
I agree that the wheel needs to come off to see if it meets specifications.
The chain tension confuses me, the book says 3/4". I read on the forums 1.5". Is the correct tension measured from pressing up on the chain to pressing down or is it only in one direction?
 
The book spec of 3/4" is the total movement of the chain. Don't press down on the chain, and just lift until you feel light resistance. The gremlin can hide but it can't run, you'll find the little SOB--good hunting!
 
If you change tires, I would stay with the same 130 (stock size), just get a different brand. Tire widths, even though the same indicated size, can vary slightly between manufacturers.
 
Yes I have disc mags. I will double check the bead when I get home. The tire tread is worn enough where if I was to have to mess with it, I would just mount a new tire. Is there a tire that is known to run a bit smaller or should I just look at a120/90 tire.
In my head, the root cause of the problem is the new x-ring chain which runs wider. That plus the lack of chain stretch requires my wheel to move forward.
If I am under proper alignment, and the tire hits the chain, either the tire sidewall needs moved to the right, or the chain to the left. Either that or my swingarm isn't straight which causing clearance problems when keeping my wheel aligned. But the swing arm doesn't have play so I think I can rule that out.

Hi Kathos,
Although post#1 said 130/90-16 it took you until post #8 to say your bike has disk brake mag wheels, ah well.
With that finally established, here's my take on the problem.
XS650s originally ran a 4"-18 (then a 110/90-18) rear tire.
The Specials were swapped to a 5"-16 (then a 130/90-16) rear tire without any frame changes to better install it
so the fatter 16" tire is just shoe-horned in there with marginal to non-existent clearances
Yes, they moved the upper shock mounts and the fender attachment points etc. But increase the tire clearance? No.
And us Special owners have to cope with that.
Check the swingarm by seeing if the rear and transmission sprockets are lined up properly.
Check the cast wheel's rim for running true by spinning it by hand while holding a screwdriver(or a pencil, or whatever)
next to the wheel's polished outer edge.
Check the tire the same way.
If the wheel has less than (say) 3/16" total run-out I'd accept it was good enough, Others may be more (or less) rigorous.
And not all tires that say they are the same size ARE the same size, your current tire may be one of the fat ones.
FYI, my Heritage Special is running a Kenda Cruiser 130/90-16 on it's cast drum mag wheel and the bike's #530 O-ring
chain (1" width over the pins) JUST clears the tire which in turn JUST clears the brake side swingarm.
 
I recall IRC Duro tour tires being "over size" compared to other mfg's tire of the same size ! This is remembered as a guy (me) who did most of the tire changes in that shop. I would do a side by side comparison at a local shop if possible before selecting a different tire ?
 
Thanks for the information guys. I got some tests to do. How do you check if the sprockets are lined up?
I'm almost positive my tire is running on the larger size. I've had issues with its fitment since I bought the bike before I bought the X-ring chain.
Taking it to a tire shop to find tire that fits crossed my mind. I was hoping the forum could save me from that.
 
Thanks for the information guys. I got some tests to do. How do you check if the sprockets are lined up?
I'm almost positive my tire is running on the larger size. I've had issues with its fitment since I bought the bike before I bought the X-ring chain.
Taking it to a tire shop to find tire that fits crossed my mind. I was hoping the forum could save me from that.

Hi Kathos,
check the sprocket alignment by removing the leftside engine cover casting and the drive chain to see what you are doing
then stretching a length of string across the faces of both sprockets.
And you plan to replace the existing tire anyway?
Take the wheel to a tire shop and ask them to fit the narrowest 130/90-16 tire they have got.
 
I checked the wheel and tire to see how true they ran. The wheel was perfect, the tire was out about an 1/8 overall.
For future reference, the book says that a wheel should be renewed if it runs .07" out of spec. Thats 3/32"s. I am not sure if that is 3/32" to each side from center, or if its total from left to right.
Fred, I like the look of the Kenda, if it fits your special with an o-ring.. any reason it shouldn't fit mine?
 
I checked the wheel and tire to see how true they ran. The wheel was perfect, the tire was out about an 1/8 overall.
For future reference, the book says that a wheel should be renewed if it runs .07" out of spec. Thats 3/32"s. I am not sure if that is 3/32" to each side from center, or if its total from left to right.
Fred, I like the look of the Kenda, if it fits your special with an o-ring.. any reason it shouldn't fit mine?

Hi Kathos,
Most likely the measurement is TIR (Total Indicated Reading) so yes, the total.
If your X-ring chain is the same 1" maximum width as my O-ring chain yes the Kenda should work for you.
 
I just wanted to follow up on this. I ended up buying the Kenda off of amazon. Arrived at my house in a few days. Immediately I noticed how flat the side walls were on the Kenda compared to my Duro's bulgy sidewall.
After I got the tire mounted and balanced, I installed the wheel back on the bike. After proper chain tension/ alignment, there is almost 1/4" on each side of the tire. What a huge difference. Plenty of space to play with and no more worries about rubbing chain/ torque arm. Thank you everyone for your help/input.
 
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