Help Avon?

[Iowa Guy]

Got my 89 back from the mechanic after what I thought was going to be some general repair and inspection. I had the rear shock replaced, the right front brake replace and greased the steering bearings. Paid my bill and rode it away but approaching the first stop sign at about 35 mph, I let up on the throttle and the handlebars went into a significant shimmy, shake, oscillation. On the highway, it settled down at about 50mph but reappeared at the same speed when I braked with the engine. I immediately returned to the mechanic. He said that he knew it was a problem but didn't know what to do. He wondered if it was the Avon Tires. He pointed out that on the front tire, there was a cup in the rubber on alternate sides of the tire just below the diagonal slash. In other words, facing the front of the bike looking at the diagonal slash on the bottom side of the highest part of the slash there is a cup. (Should of sent a picture). He wondered if the shimmy was due to the cupping.

 

Seems to me that the speed would be too slow to have the tire issue effect the handle bars

 

A couple years ago, I fixed an oscillation by removing the ignition cover over the steering head and rapping the big nut with a screwdriver and hammer.

 

I've got an new Avon front tire in my garage and could put it on but would rather not since the one on the bike is not worn out yet.

 

So, whadda ya think? Is it the Avon or is the steering too loose?

 

Anybody else have this problem?

 

Iowa Guy

 

I wanna ride my bike

[Marcarl]

There's a post in the tech section on how to tighten the steering head, actually you tighten them until you have very little bounce on the handle bars when you push them over. Cupping on the tire is not going to help your situation, but from what you discribed your steering head needs tightening.

[hipshot]

There's a post in the tech section on how to tighten the steering head, actually you tighten them until you have very little bounce on the handle bars when you push them over. Cupping on the tire is not going to help your situation, but from what you discribed your steering head needs tightening.

 

i agree with carl.

under tightened steering head bearings would be my FIRST concern.

second would be the tire.

under NO circumstances, would i ride the bike with that problem, other than to check and see if the adjustments, made any difference!

just jt

[flb_78]

If you just paid them a butt-load of money to fix your bike and it comes back worse then when it went in, I do believe they have some double checking to do. I wouldn't touch anything until they went over the bike again. If you start tinkering with it and make it worse, they'll claim that you caused the problem to begin with.

[Iowa Guy]

I've done some research into the service manual and posts here. I will return to dealer today and recommend that he check for loose steering head. Thanks for the advice.

 

Iowa Guy

[pegscraper]

He had the steering bearings apart to grease them and now it shimmies and shakes? Like everyone else said, he didn't tighten them up enough when he put it back together.

[Iowa Guy]

So, to wrap things up with a question: I went ahead and put a new avon on the front of the bike and the handling problem disappeared with no tightening of the steering head nut.

 

Has this happened to anyone else who has had Avons and how can it be avoided?

 

Iowa Guy

[hig4s]

So, to wrap things up with a question: I went ahead and put a new avon on the front of the bike and the handling problem disappeared with no tightening of the steering head nut.

 

Has this happened to anyone else who has had Avons and how can it be avoided?

 

Iowa Guy

 

That does not mean the steering head nut is correct, especially if it did not shake with the old tire on the way to the shop. You have now added more variables, and the new tire may just be able to mask the actual issue.

 

As far as the cupping of the tire goes, that generally occurs from using the front brake while going into a turn. If you don't use the front brake except when the bike is not leaned over the tire should not cup.

[Iowa Guy]

That does not mean the steering head nut is correct, especially if it did not shake with the old tire on the way to the shop. You have now added more variables, and the new tire may just be able to mask the actual issue.

 

As far as the cupping of the tire goes, that generally occurs from using the front brake while going into a turn. If you don't use the front brake except when the bike is not leaned over the tire should not cup.

 

Let me complicate it more. The mechanic said that the bike did not show the problem when I brought it in because the steering head bearings were dry so would not allow the shaking to occur. When he greased them it freed them up to shake.

 

Regarding braking on a turn: I learned the hard way about only sparingly using the frount brake. Now, I only gently use the hand brake as an extra if the foot integrated brake is not enough. Yes, that would mean that pushing the pedal, the front brake would be applied but only in coordination with the rear brake also.

 

comments invited

 

Iowa Guy

[sarges46]

Let me complicate it more. The mechanic said that the bike did not show the problem when I brought it in because the steering head bearings were dry so would not allow the shaking to occur. When he greased them it freed them up to shake.

 

 

comments invited

 

Iowa Guy

 

Sorry, but am I the only one having a tough time swallowing this from the mechanic? Even so, he should have tightened the steering head so it doesnt shake, or if they were that bad he should have replaced the bearing.

 

Whatcha all think?

[Rocket]

Sorry, but am I the only one having a tough time swallowing this from the mechanic? Even so, he should have tightened the steering head so it doesnt shake, or if they were that bad he should have replaced the bearing.

 

Whatcha all think?

 

Nope, your not the only one, Rick. It shows his competency level, better start looking for another mech, or learn to do basic maintenance yourself.

 

There are dealers out there, that may be an ok source for parts, but I wouldn't have work on the scoot, more than once. If they can screw something up on a tire change, would you want them digging deeper into the scoot???

[Eck]

Before I jump all over the mechanic, I would lift the front wheel off the ground and perform the bearing check first to see if the handle bars fall easily to one side or bounce back after touching the stops.

I wouldnt be blameing the mechanic anything ....yet..

 

If the bearings and races were dry, and showed no signs of any damage I sure as heck wouldnt replace them either, and would not want my mechanic to install new parts with out first letting me know and to save all removed parts for show and tell on pick up day.

Adding the new front tire did add more vairibles..however, the loose bearing check with the front wheel off the ground will determine if it was or is a loose steerring head bearing and remove that vairable... if the steering bearing IS oose, then by all means, you have the option to take it back to the mechanic or just tighten it up yourself, provided you have some level confidence within yourself that you know what the heck your doing.

You already have the wheel off the ground.. heck go for it....and then go ride..

I wouldnt want to leave my bike with the mechanic any more then I have too..

[Gearhead]

I'm a little late here, sorry. First,

Seems to me that the speed would be too slow to have the tire issue effect the handle bars

30-40 mph is the classic speed range for a front-end wobble, esp. when decelerating. Read up on it. A worn, even half-worn front tire, is definitely cause for it. I've wondered before if it's all related to funny wear patterns, or if it's partially the tire getting out of balance. I've been gonna re-balance a tire when it starts that behavior, but never got around to it. The new tire almost always stops the problem cold, in my experience. (I say almost, because on my 87 VR the problem persisted through a new tire, but was much reduced.) Usually those wobbles require just the lightest of pressure on the handlebar to prevent or stop, so maybe yours is more severe than average.

 

Second, I have to disagree with the popular sentiment here that the mech is full of crap and incompetent because of this. Maybe he is, maybe not.

Let me complicate it more. The mechanic said that the bike did not show the problem when I brought it in because the steering head bearings were dry so would not allow the shaking to occur. When he greased them it freed them up to shake.

This is completely reasonable! When the bearing is dry and stiff (or overtightened), the bike may tend to wander, but the steering head is not free to oscillate. In fact, my 87 didn't have the shimmy until I lubed dry bearings, just like you.

 

IMHO - not to be argumentative - but I don't think tightening head bearings makes for a suitable steering damper. Bearings are not designed to be tight like that. I tried that on my VR and all I got was a wandering bike that still had the shimmy. Every other bike I've ever had worked great with the head bearings tightened JUST enough to get the slop out, which is pretty much what the service manuals say to do.

 

Just my 2 cents. I'll crawl back in my hole now.

 

Jeremy

[funrider]

from what I have read, cupping on the tires, mostly on front tires, is normal and can not be avoided. It is caused by the pressure on the tire and the tread patterns when in a turn. The tread patters give traction but also cause a small amount of slippage, and that is why you will see some cupping normally and it will be in a steady pattern. As far as the dry bearings keeping it from shimmying, I can believe that, I just put new bearings in mine, they were so sticky when I took them apart that I decided to replace them, what a huge difference in handling and ease of handling.

[wild hair 39]

how i check the steering bearing---on a slite up grade,let the bike roll backward,turn the wheel all the way left or right,then clamp the front brake,if there is any slop,you can feel it,then maybe compair it to another bike:080402gudl_prv: