Really wierd handling problem

[silverbird1100]

First off, this is not a grip issue, it's a turning problem.

When I'm running 42psi w/Z6's and first start riding in the morning, my bike really wants to understeer, much like when you have worn tires with a flat spot on the side. Once they warm up it starts turning like a dream. I really noticed this on my Calfornia trip when I was riding from sunrise to sunset. Especially when it was cold starting out it would take sometimes an hour of hard riding and the ambient to come up before they would start to feel normal. I might expect this with 36-38 psi but not with 42. Never a problem at all after 10:00AM.

[Helvet]

First off, this is not a grip issue, it's a turning problem.

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Never a problem at all after 10:00AM.

You probably shouldn't drink so much the night before.....

[dunedain]

Did you ping Metz to see what they say?

Could they be taking a while to heat up?

This is odd. Any chance it's just you?

[Warp11XX]

This probably doesn't explain exactly why it handles funny cold, but I've been told by a close friend who did a bunch of "research" on tires before he committed to the Metzlers that says they use a higher than "average" amount of carbon composites and compounds in their tires to change the cold weather response and abilities to operate in extreme cold temps. Metzler is the only tire in it's class that is rated to operate at temps you only find on the friggin moon. This has some effect on traction and warm up times obviously. Whether it is good or bad, I dunno... :icon_think:

[shovelstrokeed]

Coupla questions and comments.

Define cold, 0 C?, 10 C, 20C?

What was the temp when you inflated the tires to 42 PSI.?

When was the last time you checked the tire pressure?

To give you some food for thought. P1/T1=P2/T2 with temperature in degrees K and pressure in absolute value but basically unitless. So, using some assumptions.

P1 = absolute inflation pressure 42+14.7=56.7 PSIA

T1 = 25 deg C or maybe 80 degrees F anyway, 298.15 deg K.

T2 = 10 deg C or roughly 50 degrees F = 283.15

Change in pressure due to temperature = 56.7 * 283.15/298.15= 53.84 PSIA - 14.7 = 39.14 PSIG

Pretty much the same change in pressure would occur at any reasonable inflation pressure. Certainly would make a small change in feel but not a large one.

Don't have that problem at all with my Pilot Roads but so far this year, I've only seen a low of 56 deg F.

[lois]

I have been running nothing but Metzlers on both my bikes , 2 months ago I went with the M-1 /Z-6 combo on my bird, and I honestly have not noticed much difference in warm up time between the m-1 rears I usualy run and the new Z6.

Could it be that you have have a dud tire??

[silverbird1100]

To sum up, I was always aware of my cold pressure and took into account temp, altitude and my calibrated guage. By cold I'd say around 35F ambient but it was still bad below 50

I like warps theory the best. There is no doubt whatsoever it's not in my head. When it's bad, it's bad. A lot of might have to do with the fact that since it WAS so cold out I was never pushing hard enough to warm them up (mostly if not all the front tire) That being the case, if the tires was making too big of a contact patch, at normal speeds, I'm almost sure it would at least simulate a worn tire, which is exactly what it feels like. I'd have the bike over, and need to tighten my line a bit and the thing just wouldn't go...I'd really have to force it. The problem is like I said once everything was warmed up they were magic.