Hippity-hop...

[FLAVALK]

...and I an't talking about the Easter Bunny. Went for a 150 mile run today on my new front Avon Cobra and the front end hops around 35 mph...crap!  

It seems to only do it between 35-40 and then smooths right out. I was running 42 psi and wondering if this might be to high for this tire, or is the tire bad? Besides that little issue, I like the tire. It makes the front end seem lighter and it the bike falls effortlessly into a turn.

The tire I replaced was an Avon Venom. 42-psi for 20,000 miles with no issues.

Seems that I read here about someone else with a 35-mph hop with the Cobra.

[Disco]

This sounds like a balance issue.  I can't see how pressure would be the cause.  Is it balanced with either lead or dynabeads?  I have 2 ounces of dynabeads in my Venom front and it's as smooth as glass.  

[FLAVALK]

This sounds like a balance issue.  I can't see how pressure would be the cause.  Is it balanced with either lead or dynabeads?  I have 2 ounces of dynabeads in my Venom front and it's as smooth as glass.  

It's balanced with lead. Tire mounting is the only thing that I don't do in the routine maintenance of my bike. Guess I will have to start.

[Ricky-D]

If you can get the front off the ground it's easy to check the run-out of the tire.  And I don't trust bubble balancing if that's how it was done.

And yes, if there is a tire construction problem, lower pressure in the tire will tend to minimize any bouncing. A harder tire will make irregularities more pronounced.

[FLAVALK]

If you can get the front off the ground it's easy to check the run-out of the tire.  And I don't trust bubble balancing if that's how it was done.

And yes, if there is a tire construction problem, lower pressure in the tire will tend to minimize any bouncing. A harder tire will make irregularities more pronounced.

I took the wheel & tire to a local shop and let them mount & balance it, so I don't know how it was done. Guess I'll remove the wheel and balance it myself...should have checked it before I put it back on the bike. 

[Disco]

Good point, Ricky.     I didn't think of a faulty tire at new or 150 miles. 

But, if memory serves, there have been some reports here over the last year or so about Avons failing prematurely.

[dcfan2]

I had the ame problem with an avon venom.about 35mph would get a rythmic bounce.Pulled tire and had balance checked-spot on.Tire pressure made no difference.Tire had about 8 grand on it and still half of tread left.Also developed some handling issuses--possible belt broke?.Changed  to a Metz 880 and no more bounce.Possible break down in tire?

[hubcapsc]

I And I don't trust bubble balancing if that's how it was done.

they have to keep those bubble balancers calibrated.

I never heard of anyone needing to calibrate gravity 

Here's a picture I made when I did my first balance job with a static balancer...



-Mike