Is it loose or is it nerves?

[Macmatic]

So two weeks ago now I left a drive in movie here in Atlanta and the bike felt "wrong" on the way home. This was actually an all day event with bands and beers during the day and movies at night... I'd had a "few" but not in hours so at first I put my perceptions down to having been out in the sun all day and still feeling the beers on some level, after a quick stop to check tires and give everything I could think of a quick shake I continued home at a cautious speed...


Well it STILL feels funny. I've only been out a few times since then but the bike is feeling "rolly" like I can rock it from side to side more easily than I could in the past. It also seems to be feeling less stable on the highway, more prone to being pushed by the wind and wanders more in groves...maybe. Several times turns have felt wrong somehow and I've slowed and stood the bike up more...and I wasn't leaned over far to start with.

The front and rear wheel bearings seem fine, at least I can't feel any play in them or the swingarm. Tire pressure is fine and the tires have 2000 or so miles and plenty of tread left.

What can I check that I haven't? Maybe its just nerves... I don't think it feels right so it doesn't, but I don't want to get into that mindset and push it when something is really wrong.

/\/\ac

[Billy Ricks]

What air pressures are you running?

[Macmatic]

I'm running 35psi in the front and 40psi in the rear. Tires are Cheng Shins Hi-Max 110 in the front and 130 in the rear. None of that has changed since I put the bike on the road. I have to put in about 5psi if I let the bike sit for a week or so, if I ride daily it seems to stay solid on 35/40.

I have the four position dial (rebound?) on 3 and the preload set around 2.5.

/\/\ac

P.s. Billy, see my PM about o-rings.

[Billy Ricks]

I'm running 35psi in the front and 40psi in the rear. Tires are Cheng Shins Hi-Max 110 in the front and 130 in the rear. None of that has changed since I put the bike on the road. I have to put in about 5psi if I let the bike sit for a week or so, if I ride daily it seems to stay solid on 35/40.

I have the four position dial (rebound?) on 3 and the preload set around 2.5.

/\/\ac

P.s. Billy, see my PM about o-rings.

When you talk about pitching the bike from side to side I assume you mean at speed? The 23 year old shock isn't helping matters and personally I'd drop tire pressures by about 5 pounds. Correct tire pressure should be about 3 pounds higher hot than cold. Meaning that when cold if you stop and check tire pressure after about 15 minutes of continuous riding the tires at that point should register about 3 pounds higher than cold. If it is more you aren't running enough air. If it's less you have too much cold air pressure.

[Macmatic]

When you talk about pitching the bike from side to side I assume you mean at speed? The 23 year old shock isn't helping matters and personally I'd drop tire pressures by about 5 pounds. Correct tire pressure should be about 3 pounds higher hot than cold. Meaning that when cold if you stop and check tire pressure after about 15 minutes of continuous riding the tires at that point should register about 3 pounds higher than cold. If it is more you aren't running enough air. If it's less you have too much cold air pressure.

What I mean is when you hold the bars and just kind of roll the bike underneath you. I'm not even really sure if its putting pressure on a peg or shifting weight or what... it just kind of happens. I'll pay more attention next time I do it to HOW I do it.

I know the shock is old but it only has about 15k miles on it and I rebuild the preload adjuster and changed the fluid when I set the bike up. I guess the point is that suddenly the bike seems to feel different and nothing has changed that I can think of/find. Trie pressure, preload, rebound and everything else are all where I had them two weeks ago today but two weeks ago tomorrow the bike started feeling "loose" and like it wanted to push out in turns.

I guess I never really felt anything like a shake or wobble but I'd go into a turn and it just didn't feel right so I'd back off and take it easy. This all started right after a weekend in the mountains (GA 60 and 180) where I was really starting to gain some confidence in my leaning and carving too.

As for the tire pressures... They are pretty much the "2 up" numbers from the factory manual and I'm pretty much a "2 up" rider by myself at 270lbs. Also I though people were running higher pressures in these newer design tires? Anyway these pressures HAVE been good for me in the past but something just isn't right now. Any ideas on what to check? Steering stem bearings are next on the list even though I tightend them up not long ago.

/\/\ac

[flyingace]

A lot things can make a bike feel more 'loose' when cornering. Putting on new rear rubber made a big difference on my bike. It could be the shocks have given up the ghost, loose or worn swing arm bearings, wheel bearings, wheel misalignment (assuming chain drive).

Check the things that don't cost first, and if they check out, move to the things that do.

By the way, nice looking bike.

[Billy Ricks]

Check your hot vs cold tire pressures like I outlined. At least you can see if it helps and if not you can eliminate that. Set the sag at both ends at about 1 1/4" for general riding. For your weight you'll probably have to crank up the rear preload just about all the way. To set the sag measure the fork length fully extended with the wheel slightly elevated then again with your weight in the seat and both wheels on the ground. The diffference should be about 1" to 1 1/2" depending on how firm you want your suspension. At the rear elevate the wheel and measure straight up from the axle to a point on the frame or side panel. Then measure again with all your weight on the bike and wheels on the ground. Shoot for the same number as up front.

[robertbarr]

How are you checking the wheel bearings?

I had a rear wheel bearing go south on me last year, and it was impossible to diagnose the problem until I removed the wheel itself. The handling just felt wrong. Something was unstable. My butt knew there was something wrong, and it's always a mistake to ignore messages from the behind.

With the wheel installed, I couldn't feel any sign -- none -- that there was a problem. No play, nice even rolling, no noise. But when I removed the wheel, the problem was glaring. In my case, it was so far gone that it had melted the wheel around the bearing bore (and hence the whole wheel was shot). So it was probably fairly close to locking up on me whilst underway. Eeeks.

[Can_O_Tuna]

How are you checking the wheel bearings?

I had a rear wheel bearing go south on me last year, and it was impossible to diagnose the problem until I removed the wheel itself. The handling just felt wrong. Something was unstable. My butt knew there was something wrong, and it's always a mistake to ignore messages from the behind.

With the wheel installed, I couldn't feel any sign -- none -- that there was a problem. No play, nice even rolling, no noise. But when I removed the wheel, the problem was glaring. In my case, it was so far gone that it had melted the wheel around the bearing bore (and hence the whole wheel was shot). So it was probably fairly close to locking up on me whilst underway. Eeeks.

Robert's advice sound about right...I have never heard it happen on a bike , but what your are describing sounds a lot like a tire that slipped a belt

[Carter Turk]

A wheel weight may have jettisoned itself. I've found a broken Progressive fork spring when changing fork oil. I'm sure that didn't help handling any.

The back end of my bike felt funny for awhile recently. I changed the swingarm bearings and the problem is gone.

I just measured the notches on the swingarm to the back of the swingarm and found almost a 1/16th discrepency from one side to the other.

Maybe check engine bolt torque specs.

[oldschoolGS]

Wheel bearings and swingarm bearings would be the first thing I checked. When you pull off the swingarm, remove the rubber chain bumper and check for stress cracks at both pivot points. I found a nasty crack on my '83 arm right at the pivot point. The aluminum swingarm on these models is very light.

Here was my fix


Not trying to alarm you, but if something feels wrong, chances are something IS wrong.

Good Luck, Ed.
1983 GS750ED
2005 GSF1200SZ
1992 900SS

[Billy Ricks]

Wheel bearings and swingarm bearings would be the first thing I checked. When you pull off the swingarm, remove the rubber chain bumper and check for stress cracks at both pivot points. I found a nasty crack on my '83 arm right at the pivot point. The aluminum swingarm on these models is very light.

Here was my fix


Not trying to alarm you, but if something feels wrong, chances are something IS wrong.

Good Luck, Ed.
1983 GS750ED
2005 GSF1200SZ
1992 900SS

Early on im my bike's history I pull the swingarm pivot bolt and found a crack in it.

[Macmatic]

Thanks for all the input guys. I'll try and take it down this week during the evenings and see what I can find.

/\/\ac

[RobGS850L]

I think it's a good idea to check all the items in question here, but I've had an occasion or two where I've been going home or to work or whatever (I ride almost 100 miles a day) and have had that feeling that something is amiss with the bike I'm on. Usually it is something I've not payed any attention to in the past and now it's totally on my mind. A small wobble or a noise or something dumb (but not always) gets my attention. Then I over analyze the item in question and more often than not it isn't anything. Same old bike same old story. I take mine through a turn I've been on a million times and get the feel of it there and if she feels the same as usual I'm good to go. If not, then I'm checking her out. Like I said check her out because it is an old bike but after you do you'll definately feel a lot better and those little quirks won't bug you as much. Oh yeah I also like the bike dude, nice color!