New tire blues :( :(

[greg.m784]

I mounted my Avon's last night. I removed all the weights on both rims and used dyna beads when the tires went back on.  Both rims and tires where wiped down spotless, the beads were poured in and tires mounted (no spilled beads).

Tonight's 20 mile ride to break them in a little for this weekend revealed a front end wobble on decel.  That isn't ok with me!  Dyna beads come with great recommendations, so i 'assume' they are doing their job.  Do these Storm 2 tires usually result in this? 

Of course you could say "tighten your head stem bearings", but i've ridden 3700 miles in two months on dunlops and never once ever experienced anything like this.  I can feel it try to start the wobble just cruising at 65 if i relax my hands on the bars.

My steering is looser than the common "Tighten it until it won't flop to the side while the tire is off the ground".  It is pretty free to turn.  It always has been.

Why would changing to a new tire force me to readjust my bearings.  Isn't that hiding the real problem here?

 

[slybonesjesse]

what size avon on the front

 

[greg.m784]

110/80ZR18

 

[CTCHRISF]

I've had a snarly head shake with the avons, think it was about 45-50 mph. that was hands free. soon as I tapped a hand down it went away with no real drama.

 

[greg.m784]

One thing i'm worried about with snugging up the headset is slowing down the steering.  Because i've never made them tighter, i don't know what it will do to the feeling of turning the bike.

 

[greg.m784]

What is the proper pre-load on those bearings?  They are tapered bearings, correct?  roughly 1 1/4"?

 

[bmcush]

What is the proper reload on those bearings?  They are tapered bearings, correct?  roughly 1 1/4"?

There is a spec in the shop manual but it's incomplete.  It provides a torque spec at a specific distance but then doesn't tell you the distance.  Anyhow, just tighten the head nut in 90 degree steps until the wobble disappears.

 

[Sparkie]

One thing i'm worried about with snugging up the headset is slowing down the steering.  Because i've never made them tighter, i don't know what it will do to the feeling of turning the bike.

You don't want to overtighten the bearings so that its hard to turn the bars. That would be way to tight. My bike did the same thing when I went to Avons from the stock Dunlops-can't tell you why. If you have never adjusted the bearings its time. Start in small increments like a previous poster mentioned. I'm guessing you'll find them way loose ands thats why you can feel the wobble now. Its really not hard, just don't forget to loosen the bottom pinch bolts on the triple clamp when you snug up the collar on the bearings. The forks must be free to slide and take the adjustment. Good luck, Mark

 

[Ranger Jim]

I think the wobble when going from Dunlops (or whatever) to Avons is due to a difference in tire profile. I also think the Avons steer "quicker" so perhaps the Avons are more sensitive to bearing tension. None the less, it seems to be a fairly common issue and is (usually) solved by adjusting the steering head bearing.

 

[willyp]

+1 for Jim. This same thing has been reported over and over. With time your head bearings loosened slightly, you did not notice with the old tires because they were of a more stable, slower turning design. Now, put a newer quick turning, less stable design tire on the front, and the wobble becomes more noticeable.

 

[willyp]

One thing i'm worried about with snugging up the headset is slowing down the steering.  Because i've never made them tighter, i don't know what it will do to the feeling of turning the bike.

Less effect than a steering damper. But same idea.