wandering, loose feeling

[Guest]

Hello folks. I have been feeling the sensation that my 1100gl wanders slightly while on the highway, like something is loose.

The wheel bearings are new as are the tires (2 years old). Steering stem bearings are not notchy and rotate smoothly. When on the center stand I cannot detect any play in the swinger either. Is there anything else that could cause this? Suspension is all new also, progressive fork springs and shocks.

This bike is outfitted with a windjammer V with lowers and has KG hard bags and trunk. Could it be the way the wind moving around all this making the handling feel this way? Or maybe I have just gotten used to the way the 91 G rides?

Any insight will be greatly appreciated. This is driving me nuts.

[bonanzadave]

Tires good ? Tire pressure ? Yes, the luggage will do that. Are the head bearings tight? Too tight?

[dr_fosg8]

Hi Dave,

Yes tires are good only 2 years old, about 6000 miles on them. I don't think the steering bearings are too tight, they are set about the same as my 91 G.

You mention tire pressure, would too high a pressure or too low a pressure cause this? I am ashamed to admit that my front tire was at 20 psi, the rear was still at 40psi. Should be at 28 and 40 per my manual I believe for continuous highway riding.

Thanks for the fast reply

[UncleMike]

28 psi sounds really low.

[TheCafeKid]

First 20 psi is really really low. Dangerously so and that alone would cause your bike to feel funny. Especially with 30 extra pounds of windjammer over it.
Secondly, tire pressure is one thing you can ignore that manual about.
Those numbers are based on a stock bike, with factory installed tire types.
Tires aren't the same they were when your bike was built. Many of them work better with pressures quite a bit higher than your manual suggests. Avon Road Riders for instance, I've found, perform better at about 36lbs on the front and 38-40 on the rear. You've added weight with the Vetter stuff so that changes things as well.

Ideally, to gauge your ideal tire pressure given the application, measure your pressure cold, the measure it again hot. If it changes more than two or three pounds, you're not running the correct pressure for your application.

Added weight requires a bump in pressure. Two up, bags etc.
One up, with those Avons I love so much, I ran 36f, 38r. Two up I added two pounds to each after measuring cold then hot. Worked pretty well.


Also, some things to check. Steering stem nut should be tight. Not hand tight. The book suggests a special wrench to tighten it adequately, but a drift/center punch and a rubber mallet work well enough.
Check your shock bushings. I know you said they're new-ish shocks, but broken down bushes will make it feel a little weird and nervous.

Swinger bearings/bolts. Break out the torque wrench.

And if all that checks out, double check you don't have a fork leg binding...

[Dakotakid]

Honest question here:
when you run this much air (as suggested), don't your tires simply wear out a skinny little section in the middle and substantially shorten tire life?

During this last week (Sturgis rally), I followed a lot of bikes and so many of them were only showing a 1.5 inch sliver of a contact patch (out on the flat sections of road) while the remainder of tread never seemed to see any action. OK, fine....most of these were friggin Hardleys.....but, the concept remains a constant.

What about encounters with gravel when running a higher pressure? In the Black Hills here, there is always the potential for marbles (especially after rains, etc.). A reduced contact patch with marbles is going to keep the skid marks in my undies ever present!

[Dakotakid]

Oops, didn't mean to jack the topic.
Original poster: how is your tire balance?

[TheCafeKid]

Honest question here:
when you run this much air (as suggested), don't your tires simply wear out a skinny little section in the middle and substantially shorten tire life?

During this last week (Sturgis rally), I followed a lot of bikes and so many of them were only showing a 1.5 inch sliver of a contact patch (out on the flat sections of road) while the remainder of tread never seemed to see any action. OK, fine....most of these were friggin Hardleys.....but, the concept remains a constant.

What about encounters with gravel when running a higher pressure? In the Black Hills here, there is always the potential for marbles (especially after rains, etc.). A reduced contact patch with marbles is going to keep the skid marks in my undies ever present!

I've never had a problem with reduced tire life by running the proper tire pressure, whatever that pressure may be. Again it depends on the application.
The tires fitted to these bikes when they were built are nothing like the tires available today. They may still be bias ply, but the advances in compounds are pretty substantial. Profile shapes are different, from brand to brand as well. In my example, I was using Avons AM26s. They are a what most would probably call a "pointy" tire. Very round, with the tread wrapping down past where alot of tires sidewall would start.
The bigger issue is measuring the pressure. If you start cold at 28lbs and warm is measured at 32, you're probably running too low of a pressure. To great a contact patch generates more heat in the tire. Low pressure also tends to make the bike handle slow and sloppy. It takes some experimentation, and each tire might be a pound or a few less or more for ideal pressure, depending on what you're doing with it (how much weight it's loaded with) but you ideally don't want to see that pressure change much from cold to hot.

And if you're running through gravel thick enough to wash a wheel out, it's probably not going to matter what pressure you're running.

[dr_fosg8]

Dakotakid: I don't know directly how well the tires are balanced. I took the wheels in to a local place to have the new tires mounted and balanced. I don't have any excessive vibration that would lead me to believe it was out of balance unless bikes wander and feel loose with that condition.

TCK: What would be a good place to start for checking pressures? I am looking for them to warm a little bit right, just not more than 2 or 3 psi? Today when I leave for work I will try 34 in the front and 40 in the back and recheck at work. 15 mile ride on the slab to get there should warm them properly right?

[UncleMike]

Expect tires to warm about 10%, so adjust accordingly. I'd go higher than 34 in the front.

[TheCafeKid]

Expect tires to warm about 10%, so adjust accordingly. I'd go higher than 34 in the front.

Agreed.

I just watched a show on Speed channel about Lotus and their designs.
They had a segment in the show regarding tires and a designer was talking about how these silly wide "performance" tires are completely unnecessary with today's tire development, design and compound tech. But most people, when they think high performance tires, they see these wide beefy low profile tires as the pinnacle. The guy went on to explain how back in the day they were necessary to deal with the high HP and still retain great grip for racing. Now days they can get the same handling characteristics out of much narrower wheels and tires, which also decreases unsprung weight. Lotus has always been about lighter, more nimble cars being able to win vs big horsepower. And theyve proven that more times than anyone (still the only manufacturer to have championships in every major auto racing series from Indy to F1 to rally car etc)

Anyway, my point is, while these bias ply designs are still a bit old school, the designs and compounds aren't, so a smallish contact patch isnt necessarily a bad thing.

[dr_fosg8]

thanks folks

Well it seems the air pressure in the tires was indeed the problem. Went out today with 38f and 41r and after warming up the tires I was at 41f and 45r. Also the wandering feeling is gone.

[UncleMike]

Glad to hear it.

[OldVet66]

I've been running 32 rear and 37 front. It seems to be the best combination I've found for all types of riding. Since local bridge construction took out my normal way to work until September, I'm riding gravel roads neighborhood streets and divided four lane highways to work every day. Some of the roads have some very nice twisty sections and a one lane bridge over a creek that is made for GS air time.