Metzeler Z8: good news / bad news

[Erci]

The good news: I am capable of perfectly balancing motorcycle wheels using my static balancer. I confirmed this by taking my front wheel to a shop with dynamic balancer.

The bad news: my bike has had a pronounced wobble since I switched to Z8s, about 2 months ago. It's most evident at around 55-60mph (easy to feel at the handlebar). If I let go of the bar, I can see bar ends oscillate about 1 inch). I was very much hoping that the cause was improper balance (since this was the first wheel I balanced myself).

I've talked to Metzeler and they said it could very well be a bad tire. So.. my shop will be reaching out to Metzeler next week to get me a replacement.

This is NOT a Metzeler bashing post. Plenty of manufacturers have put out bad batches of tires (remember the early batch of PR3s where the tread separated from the carcass??)

Just a bit of bad luck.

 

[Motogiro]

The good news: I am capable of perfectly balancing motorcycle wheels using my static balancer. I confirmed this by taking my front wheel to a shop with dynamic balancer.

The bad news: my bike has had a pronounced wobble since I switched to Z8s, about 2 months ago. It's most evident at around 55-60mph (easy to feel at the handlebar). If I let go of the bar, I can see bar ends oscillate about 1 inch). I was very much hoping that the cause was improper balance (since this was the first wheel I balanced myself).

I've talked to Metzeler and they said it could very well be a bad tire. So.. my shop will be reaching out to Metzeler next week to get me a replacement.

This is NOT a Metzeler bashing post. Plenty of manufacturers have put out bad batches of tires (remember the early batch of PR3s where the tread separated from the carcass??)

Just a bit of bad luck.

I can only assume you see no anomaly when looking at the tire spin after mounting the wheel to the bike.

A one inch wobble has got to be scary!

 

[Circle]

Good on Metzeler backing it up with a replacement.

That is one a scary wobble!

 

[Erci]

I can only assume you see no anomaly when looking at the tire spin after mounting the wheel to the bike.

A one inch wobble has got to be scary!

Visual inspection shows no abnormalities. Surprisingly, the wobble is not scary at all. It's just annoying. Resting hands normally on the bar is enough to keep the bike completely stable, but it translated into extra vibration.

 

[Erci]

Good on Metzeler backing it up with a replacement.

That is one a scary wobble!

Yeah, I'll be very please if they do come through with a replacement.

 

[trepetti]

What kind of air are you using to inflate your tires? That could be the problem.

Sent from my Nexus 7 using Tapatalk

 

[Erci]

What kind of air are you using to inflate your tires? That could be the problem.

Sent from my Nexus 7 using Tapatalk

Jersey air!! Now that I think about it.. you may be right! :rof:

 

[Red Wazp]

Metzlers suck. :Flip:











Nothing like a good tire war to help get through winter :spank:

J/K Erci, hope Metzler takes care of you.

 

[Humperdinkel]

Nothing like a good tire war to help get through winter :spank:

Sorry mate..... To busy riding to get involved !!! :Flip: :Flip: :Flip: :Flip: :rof: :rof: :rof: :rof: :rof:

 

[Humperdinkel]

Good news.... 3rd set of Z8's & 2 sets of Z6's before them & never experienced this said behavior :thumbup: must be just a dodgy donut

 

[motojoe122]

The good news: I am capable of perfectly balancing motorcycle wheels using my static balancer. I confirmed this by taking my front wheel to a shop with dynamic balancer.

The bad news: my bike has had a pronounced wobble since I switched to Z8s, about 2 months ago. It's most evident at around 55-60mph (easy to feel at the handlebar). If I let go of the bar, I can see bar ends oscillate about 1 inch). I was very much hoping that the cause was improper balance (since this was the first wheel I balanced myself).

I've talked to Metzeler and they said it could very well be a bad tire. So.. my shop will be reaching out to Metzeler next week to get me a replacement.

This is NOT a Metzeler bashing post. Plenty of manufacturers have put out bad batches of tires (remember the early batch of PR3s where the tread separated from the carcass??)

Just a bit of bad luck.

Just saw this Eric, this is exactly what my shinkos are doing. The store I bought them from asked if it was just the front, I said no its both. They quit talking to me.....

 

[agf]

I hope it gets sorted for you Eric, my Z-8s are terrific, and I wouldn't put my name to anything I felt unsure about

Adrian G Flint..... there I did it!
lol

 

[Erci]

Just saw this Eric, this is exactly what my shinkos are doing. The store I bought them from asked if it was just the front, I said no its both. They quit talking to me.....

If the balance is good, it's got to be the tires. There is a very small chance that it's the brakes, but this is very unlikley.

Supposedly, if the pistons are sticking and the rotors are ever so slightly warped, pads heat up and may grab in the warped spots. Does not seem like a logical explanation, when going from perfectly smooth ride to immediate wobble, by swapping tires.

 

[pulsar2]

If the balance is good and the tires are of good shape - no cupping etc... can the head/swing arm bearing cause that kind of wobble?

 

[lawlberg]

Sounds like a dominance issue. Bike forgot who the alpha is - that's all.

Pop a wheelie and slam on the rear brake, that should straighten out your tire. If it doesn't, you just have to keep doing it until you hit it in the right place.

 

[Erci]

If the balance is good and the tires are of good shape - no cupping etc... can the head/swing arm bearing cause that kind of wobble?

Can it? I suppose, but as I mentioned before, it shouldn't suddenly happen just by swapping out tires. I did check the the head bearing.. it's all good.

The best way to test this would be to borrow a wheel from another FZ1.

 

[Ssky0078]

I haven't removed or put on a wheel on my bike yet, but if there is a slight difference between each side where you tighten the wheel lug down, won't you get a vibration?

 

[Erci]

I haven't removed or put on a wheel on my bike yet, but if there is a slight difference between each side where you tighten the wheel lug down, won't you get a vibration?

You lost me there, Sky. FZ1 uses an axle which is inserted from the right side of the bike and is threaded directly into left fork leg. It has 1 pinch bolt on right fork leg to keep the axle from backing out.

Wheel lug?

 

[regder]

I've seen this many times on car tires, but never on bike tire. Theory is the same though. You likely have a separated belt also known as a shifted belt.

 

[lawlberg]

This sounds highly likely - (separated belt) if I understand it correctly - it's like having a bump in the tire because where the sections of the tire were laid together and have a slight overlap. It's uncommon because tire making is a highly skilled trade, but not unlikely based upon the fact that tires are assembled by hand. It's a ridiculously manual process compared with just about every other form of manufacturing. The green tire (prior to being cooked/molded) is assembled on a rotating drum, if the layers don't line up properly you'll have a segment of the tire where the cords/belts (steel and/or fiber) are thicker. The tire won't really appear to be any different because the soft rubber on the outside is pressed into a mold, but the carcase underneath won't be smooth.

If you ever get a chance to go on a tour of a tire factory, do it, (don't wear white), it's such a dirty, loud and hot/labor intensive job but there are some really neat things going on in there.

If that's the case, Metzeler can replace it and when they get the tire back they'll probably pull it apart, see their mistake and recycle it.