Bad tire, bad mounting?

I got my new tires installed last week. Michelin Pilots.

I pulled the wheels and had a local shop mount and balance the tires.

When I took my first ride with the new tires, I noticed vibration and sort-of bouncing, even on very smooth roads.

Looking at the rear tire with the bike on the center stand, I saw that, which the wheel seemed to be running true, the tire has a back and forth wobble (I'll see if I can post a video). I also noticed that the ridge of molding near the rim edge sticks out an uneven amount from the rim from one side to the other. Near the stem there's about 1.4mm visible, while, around the side opposite the stem there's over 3mm.

Wondering if this is a bad tire, or something about how it was mounted. I used to install car tires when I was in college and never saw any issue with mounting that could cause a tire to be off-center, but maybe there are such considerations for motorcycle wheels?

Thanks,
Paul

 

You referring to the bead line?...pic attached

 

Perhaps it's the wrong size tire or poor mounting. I hope they didn't bend the rim.

 

Yes

 

They are the correct size tires. Same as previous. 120-90/18.

Only the tire is wobbling, not the rim edge.

 

If the rim is true, I'd suspect poor mounting. The bead is not set right. Is it mounted in the correct direction?

 

Yes, the directions are correct for both. The arrow is much more subtle on the rear one, though.

 

The bead line must be even all the way around...that is the purpose of the bead line. If it is not, then the bead isn't seated properly. Take it back to where you had it mounted.

 

How in the hell did they balance it!!

 

You can try pumping it up to 50-60 psi to see if it pops in place.
If not then take it back as @TJ stated

 

take the wheel off, let the air out, step on it where it's in question, it should pop off the bead because it's not really on the bead, spray the area with (i use foamy window cleaner) something,
and put air in it till it pops on, no problem. i've never had a "professional" mount a tire. if he didn't balance the wheel before he mounted the tire, there's too much weight on it

 

I've had problems in the past with tyres not sitting concentric with the rim - more so with tubed set-ups. Can be hassle to 'cure' but if you paid a shop to do it they can try again - unless you want to.
It's a reminder to all of us check them before you leave the shop.

 

Not that easy to check in the shop. It's not even that easy to see on the bike until you're looking for it... i.e. start the bike and put it in gear while on the center stand.

I've had probably four sets of tires mounted and balanced by these guys. One set while on the bike, the other three sets with me bringing in the wheels and tires. First time I've had a problem.

When I was in college, I installed tires at Sears. Never saw a tire not sit right like this.

And, as to Polock's comment, no, we, at least, never balanced a wheel first, before installing a tire. I was always taught that you wanted only one set of weights per side per wheel. Stem markings, for tires that have them (I think they're going away now) are supposed to offset versus typical light points of wheels, too, and result in less weight. Maybe some places do this with balancing the wheel first, but I've never seen it and I don't know why to expect that that would be more likely to result in less weight.

 

Balancing the rim without weights and tire on, determines where the heavy spot is. You would think it would be at the valve but I rarely find this to be the case...usually it's close, but sometimes I'm surprised how far off it is. If you match the "stem mark" on the tire with the heavy spot on the rim you would have less weight than just putting the "stem mark" by the valve. Personally I've never found it to be more than a fraction of an ounce.

I'm doubtful that any tire shop would bother to do this, unless it has a lot of weight added...

Doubtful they check runout either, unless you ask.

 

Unless you know where the heavy spot of the tire is, what good does it to do you to know where the heavy spot of the wheel is? New tires often don't seem to have stem markings. You'd have to balance the wheel, mount the tire, then see where the new heavy spot is, then, probably, unmount the tire, remove the weights from the wheel, remount the the tire to offset the tire and wheel heavy spots, then rebalance again. If I had my own dynamic balancing machine and tire mounting machine, I might do that. I guess a shop might, too, if you are willing to pay them two to three times the normal mounting and balancing charge.

Runout of this tire, as mounted, is about 35 thousandths. It's pretty obvious to the eye with the wheel spinning and the bike on the center stand.

 

Yes, knowing where the light spot of the tire is key.

 

you put the tire on the wheel, put it on the balancer, no air, and spin the tire on the wheel till it's close or your dots line up, air it up and balance it
my cheap tires all have dots

 

If you know where the heavy spot is, you know where the light spot is. They will be 180 degrees apart.

 

My cheap tires (Shinkos) also have stem markings. These Michelins do not.

Regardless, you are talking about static balancing, not dynamic balancing. Professionally, I've only done car tires, which you generally cannot spin on the wheel with no air - they fit the wheel too tightly. Aligning the stem mark on a car tire requires knowing how the tire will shift as you mount it to the wheel and setting the tire in place correctly before using the machine's iron or arm to press it onto the rim.

 

i hate myself for bringing this up, so let me apologize before you read the next line
Dyna Beads http://www.innovativebalancing.com/
sorry