Intermediate Wobble

[triharder]

So i recently replaced my tires with some pirelli angel Gt's. A new front from Revzilla and a slightly used rear from a friend.

I also recently bought a no-mar tire changer (group buy with some friends) that came with a wheel balance stand.

Changing the tires was pretty straightforward. Some people mentioned to watch the video for tips and tricks. After swapping the tires I remounted and have done approx 100 miles.

I have two issues going here.

First, not always but the front end seems to hunt. (if you are cruising at 40 mph and coast with your hands covering but off the bars the bike seems to hunt the front end through the 30 mph mark. (its fine from 40 to 32ish then wobbles from 32 to 29 and then seems to clear up). Under hard acceleration it feels fine.

I re-conducted the front wheel install instructions (bouncing the front end) and upon riding again the other day she still didn't feel correct. Its not wrong as in scary at all speeds and it doesn't seem to hunt as drastically as that first day but it still feels just off. The second ride i re-filled the tire with air and still feel the "not quite right" feeling with the front end.

I'm convienced its my front tire (the back won't cause the front to hunt).

The bike did not do this (straight line stuff) with the old tire (which was cupped, warped and outta rubber).

so balancing the tire seems like a likely cause but when we balanced it didn't seem to want to fall in the heaviest spot of the tire. The tire seemed to have different heavy spots very 30-35% rotation. You'd let it fall it would stop then move it 90 degrees and it would fall in a different place. I took that mean the balance was pretty good?

Anybody have any suggestions? Could the tire just be faulty from the factory? Or should i be pulling it off again and trying the remount and the balance again?

(its 25 degrees this weekend so this might not happen until spring)

Any help would be appreciated.

Side note: The headset bearings, front forks etc are probably in rough shape. I haven't lubed or changed the oil. however the problem didn't start until after the new tire install so i'm ruling all those possible causes out. Bikes at 25k miles.

Thanks for any thoughts you guys might have?

[Duc2V4]

I too have the tire changer and balancing unit and have done at least four sets of tires and have not found any real issues with any except for my friends 95 VFR750. We recently put on Michelin Pilot Road 3 tires and he said that he noticed a little shimmy when slowing down. On the balancer it did take a few tries and weights to get it just right but it did balance out. My feeling is it's the tread pattern on certain road surfaces that might be the culprit, as it does not always do what he said was happening.

The key for good results is to make sure the balance unit is level on all axis. I bought a round bubble level that I place in the center of the balance base and make sure the bubble is dead center. Like so

Once I know the balancer is level, I throw the wheel on and let it find it's heavy spot. I then mark it, then place the heavy spot at around 2 o'clock and see if the wheel goes back to the same spot. If it does, I then put the heavy spot at 10 o'clock and see what happens. If the heavy spot is always the same, I then start placing weight on the opposing end of the wheel and start over. I have had one wheel give me a false positive but once I found the true heavy spot, counter weighting the wheel worked like it should. Other than the issue my friend reported, I have not had any issues with any other set I have changed.

That being said, is this your first stint with the Angel GTs? And what tire pressure are you running?

[triharder]

First time with pirellis on the Vfr. I rode michelions last 2 sets. However my last set of the road 2s wore really odd. Think cupping on the sides just off center. So bad if you took corners on ramps at 35 the whole bike would bounce up and down. Kinda like the concrete highway bounces ver seams. At full lean they felt great so I just keep pushing them.

Anyway, I'm going to unmoving over the winter and powder coat the rims.

I will re balance with a level. That's a good tip. We balanced on the garage floor with no thoughts of leveling the balancer.

I'm hoping it's just balance.

I'll be doing the forks, fork seals and maybe some upgrades on that front. I'll also lube the headset over the winter.

Thanks again. If the weather warms up I'll balance and post up how it feels.

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[FJ12Ryder]

Make sure your cones are seated firmly in the bearings so you don't have a freedom of movement by the wheel when balancing. That will throw off the balance and make it do what you are describing.

Double check that you got your spacers back in correctly.

I'm assuming that you checked the wheel bearing for smooth operation and no play.

Also double check the tire for runout to make sure you have the bead seated perfectly, and don't have a spot that didn't seat correctly.

My bet would be your head bearings are toast and are causing the wander. You never noticed it with the other tires since they were shot, but with good tires and a different profile the bad bearings pop up like a bad penny.

[Duc2V4]

It's quite possible that your wheel and/or head bearings are going. Since you have to remove the bearings and seals from your front wheel before you powder coat the rim and you plan on checking the head bearings, you might just want to replace them anyway. The only issue here is that if the issue goes away, you really won't know what cured it. But as long as the problem goes away, it's all good IMO.

[triharder]

Thanks guys. I have the new wheel bearings on standby, I'll go ahead and get some new head bearings.

Looks like being off balance is most likely the issue. I'll get a bullseye level bubble for the truing stand.

Thanks again for the feedback and suggestions.

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[keny]

I had the same issue whit my bike as I did put on a new set of Conti Roadattack2:s, after a while it wobbled around 60km/h (~30miles?) it started to wobble. It was the head bearing that was shoot, the upper. Had no grease left and had some corrosion damage from former owner/shop using power washer wrong. I guess the fact that VFRs frames get hot enough to melt the grease and the bearings dry out. New trapped head bearings did the trick for me, no wobble anymore.