Metezler Z8 Tires

The bike: 2011 R1200RT
When I was installing a new rear Z8 on my bike a while back I noticed that the sidewall seemed to be somewhat more flexible than the tires that came off the bike (Z8's also). So at the national recently I talked to the people at the Metzeler trailer about the flexible sidewall & they told me that I should be using the "O" spec tires. First I have ever heard of that. The rear on the bike is a 180/55ZR17 73W which is the same tire that the www.BMW-Motorrad.com web site recommends (among several other brands) with no mention of the "O" spec. The Metzeler web site indicates that there is a "M & O" spec of the Z8 which have different compounds & better wet weather handling.Does anyone know if the "O" spec has a stiffer sidewall & is the "O" imprinted on the sidewall?
Thanks

LCampbell said:

Does anyone know if the "O" spec has a stiffer sidewall & is the "O" imprinted on the sidewall?

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The manufacturer's claim is that the 'O' sidewalls are stiffer. What I can say with certainty is that the 'O' is imprinted on the sidewall. I see it right between the word Interact and the sizing: Interact O 180/55 ZR17.

Well, this post had me running out to the garage with a flashlight. Turns out the front Z8 is an "M" and the rear is a "C". Must stand for "Canada," or "Competizione".

Then I looked at a Metzeler website, and they don't distinguish any characteristics between the O or the M. Nor does Motorcycle Consumer News.

Anyway, I just did a three day trip on them, including a few hours in rain and lots of twisties, and really like them.

We will keep working on figuring out these mystery ratings. Harald, maybe you can post a link to your Metzeler source.

RINTY said:

Then I looked at a Metzeler website, and they don't distinguish any characteristics between the O or the M. ... Harald, maybe you can post a link to your Metzeler source.

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http://www.metzeler.com/site/de/tech-and-safety/interact.html

May not help because it's in German, but the key is "Einfache (M) und doppelte (O) Karkasskonstruktion f?r beste Performance auf unterschiedlichen Fahrzeugen", meaning "Single-ply (M) and double-ply (O) carcass construction for best performance on different vehicles".

The same single and double construction seems to go for the older non-letter and C designation respectively, which is why they used to specify the stiffer C for the rear in the past. It reads as if the main difference when comparing older (no letter or C) to newer (M or O) is the compound.

Looked at my tires again. No letter M or O. Next time I buy a set I'll know better. Thanks to all.

Talking to the same reps at the rally, I learned that the Z8 is also a dual-compound tire in the rear (and single, softer compound in front). That's a change from the Z6 Interact that was a single compound front and rear. The Metzeler rep also suggested trying the Pirelli Angel GT (in the "A spec" for the rear) next if I liked the Z8s. Very informative (as was the Michelin engineer). Cheers!

Shaun09 said:

Talking to the same reps at the rally, I learned that the Z8 is also a dual-compound tire in the rear (and single, softer compound in front). That's a change from the Z6 Interact that was a single compound front and rear. The Metzeler rep also suggested trying the Pirelli Angel GT (in the "A spec" for the rear) next if I liked the Z8s. Very informative (as was the Michelin engineer). Cheers!

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I just changed over from the Z8s to the Angel GT. No complaints with the Z8 but the Angel GT is the best handling tire I have ever had! We will see how the mileage is, but for now, I am sold!

...it's in German...hjsbmw

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Thanks Harald; I just hit the translate button and converted it.