Road wiggle during sweeping turns

[greg.m784]

I went for a longer ride this weekend, and before leaving, i aired up to 40psi, front & rear.  On long sweepers, the bike felt like i had a hinge in the middle of the bike.  I'm not sure if i was over air pressured on the tires, or maybe not enough dampening on the rear shock?  The swing arm is tight, with no side play. The rear shock had 50psi, and the dampening is on #3.  I was loaded pretty heavy (two up, clothes, water, gatorade), tank near full the entire trip.

Any ideas?

 

[bobct]

Check motor mounts, may be broken off, ask me how I know.
Bob

 

[greg.m784]

Will do.  thx.

:-\

Was thinking maybe a fork brace is needed?  It didn't feel like this on the last ride.

 

[gfinca]

Greg,

I'm thinking you probably checked the front and rear wheel bearings, but if not, that's a good place to check, too.  I remember you had some questions about adjusting the steering head bearing, were you able to do the adjustment?  "Hinging in the middle" sounds a lot like weave, the companion of wobble, and the steering head adjustment can affect that, too. 

If the motor mounts and bearings check out, the next thing I would check is the rear shock.  Try increasing the damping to #4, and see if that helps.  You might also try decreasing the damping, to see if that helps.  I would also check to see if the shock has leaked any fluid.  Look around the base of the rubber bellows and at the lower connection of the shock for any oil that may have leaked out.  Depressurize the shock and check if oil is coming out with the air.  If you notice any oil in any of these places, the seals are gone, and the shock needs to be replaced.  If there are no leaks, consider replacing the old shock oil to improve the damping.  Murph makes a kit to do the job.  HTH,

 

[smithr]

It is not the tire pressure... If everything checks out then yes mine felt better about that once I have a fork brace on.

 

[greg.m784]

I checked the headset and it is snug.  I learned to ride with the 'wobble',and since the tires have 'broken in', most if not all is gone.  These tires have almost 2000 miles on them now and up until yesterday, they felt rock solid.  Something changed yesterday on hwy36.  I'll check the shock and see how it looks. 

Thanks all for the ideas.

PS: from Sac, out hwy 16 to 20, to 1, up to 36 and over to Red bluff is a kick ass ride.  660 miles in two days.

 

[Ranger Jim]

I suspect your rear suspension is not set correctly for the weight.  That can make the bike feel like it's hinged in the middle.

 

[greg.m784]

I checked everything i could think of last night, and i can't find anything wrong. I suspect i had the weight loaded wrong on the bike.  One night this week i'll go hit 49 and see how it feels. 

I did have a bit of weight in the bags, and a few bottles of powerade, and i suspect those add up quick.  4# a piece? 

 

[bergmen]

If everything is in order (steering bearings, swing arm bearings, all four engine mount bolts, both wheel bearings, tire pressures, wheel balance, rear shock settings, minimum weight behind the rear axle), then I have to say that you are experiencing the inherent weakness of the stock Concours front forks. They are torsionally weak and can exhibit exactly the symptoms you describe here.

I experienced the exact same thing, especially with a full-on touring load (still with minimum weight behind the rear axle). I called it the "weebly-wobblies". After installing the ZRX front end and modern radial tires (Avons), the problem completely disappeared. I mean totally.

You don't have to go this route though (although I do recommend it). You can gain considerable front fork rigidity enhancement by installing a good, strong fork brace. I did that on mine before going with the Rex forks and it helped tremendously.

Hope this helps.

Dan

 

[greg.m784]

I'd love to update my forks, but it's not in the cards YET. 

I see a brace coming soon. 

FTR, i had a 92 Virago a lifetime or two ago, that did the same thing.  I'll ride with it, but i don't like it.