'06 Front Wheel Oscillation

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Symetrical as the PR2 front tire is

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Not symetrical as many other tires are

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Being an engineer, should have drawn a picture I guess, rather than try to use English. Yes symetrical may not be the right word, but you get my point why the PR2's don't wobble as much when they scallop and other tires do.
Ah yes! So it is.

Your ascii art is worth several thousand words. :thumbsup:

The PR2 tread pattern may indeed help reduce the oscillation at certain speeds.
To this I agree with maddad.

Metzler and Bridgestone tires ( not symmetrical ) induced a wobble on my bike.

Pirelli and Michelin ( symmetrical ) did not.

In my experience, best-to-worst: Angel ST -> PR2 -> BT021 -> Z6 as far as wobble is concerned.

 
FWIW, the PR2 is the first, and ONLY, front tire I've run on my FJR that hasn't, at some point in its life, caused the dreaded "FJR Decel Wobble" described by so many on the forum. And at 12,000 miles on my PR2 Front, I still haven't hit the wear indicators yet.

The PR2 is a keeper in my book.

 
I also ordered some Ride-On leak plugger/balanceing stuff via recommendation by Patriot.
Ugh! I'll never put that shit in any tire of mine again! Have you seen Patriot's FJR? Are you sure you want to be taking advice from him? :eek:

And just stay away from the dynabeads.

 
I cast my vote for steering head bearings. What do I win?
A free trip to lovely Albany, NY!!

That's the whoopie prize. ;)

Steering head bearings can not CAUSE deceleration wobble, but tightening them can help dampen it out if the oscillating input is small enough.

 
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Steering head bearings can not CAUSE deceleration wobble, but tightening them can help dampen it out if the oscillating input is small enough.
Please don't tell my bike that ;)

After replacing the front BT021, re-torqueing the steering head bearings 2-3 times, replacing the front wheel bearings (one of which was crook), I finally replaced the head bearings with tappered rollers.

I haven't had any problem what so ever, touch wood.

What really peeved me off was that the only 2 things to go crook on the bike within the warrenty period, the wheel and head bearings, weren't covered.

 
Steering head bearings can not CAUSE deceleration wobble, but tightening them can help dampen it out if the oscillating input is small enough.
Please don't tell my bike that ;)

After replacing the front BT021, re-torqueing the steering head bearings 2-3 times, replacing the front wheel bearings (one of which was crook), I finally replaced the head bearings with tappered rollers.

I haven't had any problem what so ever, touch wood.

What really peeved me off was that the only 2 things to go crook on the bike within the warrenty period, the wheel and head bearings, weren't covered.
I think you missed my point.

You could have installed a steering damper and it would have had the same effect as the tapered bearings. Neither would have eliminated the CAUSE of the wobbles.

 
Ya know it's winter when threads like this go for 3 pages or more. ;)

Enjoy.

I'd like to know if his head shake went away. :huh:

 
Perhaps you need one of those tapered bearings for your head?

tin-foil-hat.jpg


 
FedEx is supposed to deliver the tires on Monday. I likely will not get a chance to mount them (no comments please, Bustanut!) until Saturday the 8th. I shall report back my results!

 
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OK, I mounted the front PR2 last night. Breaking the bead was easy. Getting the entire tire off the rim was so damned difficult that it almost killed me. Getting the Michelin on was almost as hard. One scratched up and gouged rim later (not where the bead seals though....), it is on.

It was late, but I went out for a test ride. Set the cruise for 45 mph and went into "stunt mode" (look ma, no hands!). You guys were right!!! It was rock solid, wobble GONE!!! This is with a brand new PR2, un-balanced at about 42 psi.

Interestingly, when I prepared to mount the tire, I could find no dot indicating the light point on the PR2. So I phoned the place I bought it from and the guy said something like "we called Michelin 'bout that. They claim that they are so well made that there is no light point." Cool.

I spent so much mental capital on making damn certain that I mounter the tire in the correct rotation direction that I forgot to be sure that I installed the angled valve stem the right way. I had a 50-50 chance at getting it right. Guess which way it went..... DOHHHHH!!!

After removing the Bridgestone, I can see some un-even wear. I wonder if this is indeed what you guys refer to as cupping. The tread, to both sides of center, exhibits a rythmic wear pattern of humps and valleys (it is tough to describe). Cupping????

I may not have the intestinal fortitude to put the back tire on myself after last nights trials and tribulations. May head to the stealer.........

 
The trick to "scrape free" tire spooning is to use cut-up pieces of a plastic bottles as rim protectors, strategically positioned under the tools. Just try not to leave any behind inside the tire. DAMHIK ;)

Don't believe those Michelin pukes. Based on my own limited experience with them, some of them are definitely unbalanced . They just choose not to mark them.

Been there, done that with the 90 degree valve stem the first time. Next tire change you can reverse it. .

Yes, that uneven wear is what is called scalloping or cupping, and is a perfectly normal wear pattern. It occurs because the tread blocks twist slightly when lateral pressure is applied to them. Running at higher pressure will reduce the effect by not allowing the blocks to twist as much.

Here's a good article on motorcycle tire tread wear: clicky, though he is a bit too vehement about "road crown having no effect at all", IMO. I think it does contribute a little to the left / right wear disparity.

 
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Woket,

I found the key to easy tire mount/dismount is plenty of lubrication. I bought a gallon of tire lube at my local NAPA and use a spray bottle to apply it liberally to the tire bead area. wherever the tire has to rub along the rim, lube will help. Also, concentrate of keeping the beads close together to help encourage them to stay in the middle of the rim, width wise.

I found the front tire to be easy to mount and dismount. The rear took a little swearing and grunting but not impossible.

It helps if you can get the new tire a little warm first- I put them on the driveway for an hour first in the warm sun.

FWIW, I mounted up a PR2 front and it needed weight. about 10 grams IIRC. The rear a little more.

 
Keeping the tire beads down in the rim's "well" is critical to easy tire mounting [and dismounting]. Using a large Harbor Freight C clamp and some bed iron I welded up a clamp that squeezes about 60 degrees of tire together. This gives the "slack" that is needed to lever the other side off. Some have used several clamps to accomplish the same thing but you need about six pairs of hands to do it. The rear is harder due to the shallowness of the well. As far as scratches go, Color Rite has a rattle can that matches the '06 rim color perfectly.

 
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