wobble at speed

[crazyman]

I posted this on the other forum:

I have had my darkside tire on for about 1000 miles now. All seems well.

I was out riding yesterday, and had a few chances to ride at speeds above 85. I noticed that there is a wobble that get worse the faster I go. I only notice it above 85 -90 mph. I don't usually run that fast.

I felt the wobble in the handlebars. I was trying to figure out if the darkside tire is the cause, or is it the crap Bridgestone front tire ? Almost 6k on the front now.

Would an out of balance rear tire transmit a wobble to the front ? I've not encountered this before, so I'm just looking for advice.

 

[Baggage1]

It's possible that an unbalanced rear or front might cause the wobble but I would get it checked out before going to speed again. Mine wobbles at low speed due to front tire wear. Did you balance the rear tire when you installed it? Dyna beads or Ride On are good alternatives for lead weights which can come off.

 

[crazyman]

As far as I know, the rear tire was not balanced.

I'll wait and see if I can get the front replaced under the recall. Have it checked then. I don't usually ride faster than around 75-80. Usually

 

[Sidecar Flip]

I think I posted this on the .com site....

One of the biggest causes of headshake (and one of the least dealt with) is no pre-load on the headstock bearings, a flat spot, lack of lubricant or all of them.

I'd be elevating the front end and applying forward and backward pressure at the front axle first thing, to see if there is any play. Another good test is have the front elevated, center the handlebars and then take your finger and push them off center to either the right or left. It should take just a bit of 'push' 'starting torque' to begin movement, with the front end falling completely to either side with no roughness or stoppage.

If you ride on the Interstate most of the time, it's quite possibe to flat spot the bearings because the geometry remains constant for an extended time and the movement of the forks (up and down) cause the bearings and races to flat spot. I've seen a lot of that, especially on older, high mileage bikes.

Another factor that contributes to roughness is lack of lubrication. The bearings are packed from the factory but there is no allowance to add grease (older bikes had alemite fittings). You wash the bike and water gets past the top seal (which is nothing more than a dust cover anyway) and it corrodes the bearings and causes roughness.

Any condition other than a smooth, uninterrupted lock to lock movement can cause headshake but the most prevelant is lack of pre-load on the bearings.

 

[TxRIIIRider]

What Flip said..

I had alot of head shake starting and ended up removing the front end and repacking the head stock bearings at about 12,000 miles. When I pulled the top triple clamp and got to the head stock bearing retaining nuts, I found that they were LESS than hand tight! In fact, if it weren't for the top triple clamp being in the way, they probably would have kept on coming right off. Of course, I would have been able to see that then.. lol

Checking the head stock bearings is also in the service interval chart I believe.

 

[RocketDaryl]

Front end wobble can also be caused by low air pressure. That's the first thing I'd check as it's easy to confirm or deny.

 

[crazyman]

Tire pressures are normal.
The bike is fairly new, only has 5800 miles (in two months).

I think the issue might be the front tire. It looks fairly good, but it does look like it has some serious miles on it. I didn't notice any flat spots or cupping.

Either that or the rear car tire is out of whack and transmits to the bars.

 

[Kmutt]

I think you might want to add some dyna beads to the rear. I thought you were supposed to balance anytime you broke the bead? Ill be watching to see what you come up with.

mutt

 

[Sidecar Flip]

Again, I'd be checking the air pressure and the headshake. It sounds intimidating but its so easy to check and it will so screw up the handling characteristics if it's out of tolerance, especially on a bike with as little trail as the R3 has.