Shinko 777 too wide?

[Chito]

I've been searching around and it doesn't seem like anyone is having this problem.

So I have an 81 xs650 Special. I took it to a shop to have a new tire a Shinko 777 130/90 - 16 and got it on. At the same time I had a new chain. The shop calls me and said they had a problem, but it is sorted out.

I get the bike back and the tire rubs on the swing arm on both sides. (Rubs may be too strong, but you can't see light between the tire and the swingarm when it is sitting still. I think you can hear it when you push it) The chain is in the first 1/3 of the adjustment settings. They also shimmed the sprocket out and I'm now running a 520 dirtbike chain so the chain wouldn't hit the tire.

I have a 73 tx750 swing arm on there... so I swapped it out for the 81 special swingarm... same clearance problem, so I put the tx750 swing arm back.

It's not an option to take it back to the shop and work it through them.

I was told adding a link would make the chain too long.

It looks awesome... I just can't figure out what is going on with this. I've been told that the shape of the tire just doesn't work with the bike. Anyone else running a 777? Any ideas?

 

[gggGary]

I'm not running that tire but... I wanted to put white walls on my wifes shadow, they don't make the OE front tire size in white wall. I went up a size and the tire rubbed on the fender. I got out the belt grinder and removed last bit of the edges of the tread. problem solved, that was three years ago. It works best with the tire free to rotate. The sander spins the tire and removes rubber evenly all around the perimeter. You will kind of experiment with the correct angle to hold the belt sander to spin the tire AND remove rubber. Not for everyone but it worked fine for us. That or flatten the insides of the swing arm with a BFH!

 

[XSLeo]

Some tires are wider than others even with the same size. I did as gggGary did to run a 140 wide Dunlop on the rear of the 75. The tire was very close to the swing arm. I put it up on the center stand, idling in first gear to spin the tire. I then used my 4 inch angle grinder to take the edge of the tire back a bit.
If you look at your tire the tread surface comes over to the edge and the sidewall curves out to meet this edge. Leaving a lip of about a 1/4 inch.
I ground it back to about 1/8 inch.
This won't hurt anything. You will never lean the bike over enough to need that last 1/8 inch, not even close.
Leo

 

[Chito]

Huh... that kind of annoys me that 130 mm doesn't mean 130 mm. It's like vanity sizes... where a 32 inch waist is really 34.

What would happen if I just left it? Wouldn't it wear down anyway... I could even tape some sandpaper to the swing arm and help it along.

 

[XSLeo]

You could just let it rub off but this will create a lot of heat. This excessive heat may damage the tire. I know you will smell it. it will take awhile and never wear so there is clearance. The rubber being flexible bands around the swing arm.
Also as you let it wear off, you will find the extra drag from the rubbing reduces performance and gas mileage.
Well not so much like belts, the tire carcass may be a 130 section width. By the time they get the tread on it may not still be 130 wide.
Leo

 

[jd750ace]

The Shinko USA web site shows 5.08 inches for the width of the 130/90-16. Curiously, this is exactly the STATIC dimension shown in Michelin's 2012 fitment guide for the Commander II tire. BUT, the IN USE width listed is 5.59 inches. Blow it up and set it on the ground, and it makes a difference!
Dunlop calls out a width of 5.10 inches for the same size tire in the D404 tire
The Dunlop 491 Elite II shows the same dimensions
The Elite 3 shows 5.24 for a front and 5.15 for a rear in the exact same size.
The K591 is 5.35.
All the American series (401/402) show 5.20 for width, front or rear.
The Dunlop CruiseMax is at 5.40
Bridgestone lists thiers at 5.27

As you can see, the dimensions are all over the place, and Michelin is the only one of all of them that lists static dimensions AND in use dimensions as well.
Ideally, the in-use dimension should be all they publish, since tires leaning against the wall un-mounted don't do us any good. Shave that shoulder off that thing and go. If it was on a big heavy cruiser that was taxing the tire any at all, I would not recommend shaving the shoulder, as it is part of how the tire conducts heat away from the tread block and up through the sidewall, into the bead, but on an XS, unless you run grossly under inflated, that tire won't be under any real stress.

 

[XSLeo]

On all those widths did they list the width of the rim. Any tire on a narrow rim will be narrower on a wider rim.
Some of the 16 inch rims used on the XS650 were 3 inches wide, some 2.75. I don't know just how much the difference would be with the same tire mounted on both these sizes but the 3.00 rim will make the tire wider than the 2.75 rim.
Leo

 

[jd750ace]

They only give a recommended rim width in the charts. They don't state what the dimensions are taken with, but I know the Michelin numbers are consistent with a 3.00 inch rim width, as I measured mine on my Road Star front.