Chassis diag.

[BA80]

On my SG I have an issue I'm trying to diagnose and fix with the balance of the bike. Here's the thing.....

I've always been able to set the throttle lock and take my hands off the bars on the highway and go for miles without touching them steering only with weight transfer. Since I had a little mishap last fall if I try that it rolls off to the right and no amount of weight transfer can correct it.

When I crashed the only real damage was the broken fairing and bags and the triple tree got twisted and bent my tubular steel fork brace. When I straightened out the triple tree I checked the fork tubes with a straight edge and they don't seem to be bent and everything LOOKS fine. The bike handles and rides just as well as ever it's just that "pull" that has me baffled.

I'm going to go ahead and take the forks off this winter and check them closer but I was just wondering if anyone else has run into this type of issue before. I could rid it forever like it is but it just irritates me that it's not EXACTLY right.

[jetmechmarty]

Is there any difference in tire wear pattern since the accident?

See if you can come up with a couple of 8' fluorescent tubes. Use them to check alignment back to front. If the triple tree was actually bent, I think you should go ahead and replace it. As you know, what's off 1/64" at the top could translate to a problem at the bottom.

[IanDMacDonald]

Tire wear was my first guess too. How about a spacer out of alignment, etc.? Suspension is one of those things that u bend it once, it'll never be the same as new.

[BA80]

Is there any difference in tire wear pattern since the accident?

See if you can come up with a couple of 8' fluorescent tubes. Use them to check alignment back to front. If the triple tree was actually bent, I think you should go ahead and replace it. As you know, what's off 1/64" at the top could translate to a problem at the bottom.

I haven't noticed a difference in tire wear. I still have the same front tire I had at the time. It made it's second trip to NC this year. It's cupping on the sides but my fronts tires always do due to my aggressive riding. The rear I just took off looks normal.

As far as I can tell the triple tree isn't bent. It just twisted on it's axis. However, I do see your point. It may not have slipped, it may have twisted the neck.

Another thing to look at.

[Mathh]

Did you check the wheel axle? Most of the time they bend in an accident.

[BA80]

No I haven't Math. Thank you. Never considered that.

[TADracer]

10 to 1 its the triple tree. That's my bet.

[donebysunday]

Had a Yamaha Radian after my SF, made a turn onto the freeway ramp and the rear went out, lightly touched down, spun around a couple times, stopping right on the slab. Jumped up checked myself, then the bike, scrape on the brake lever end, mirror and cap on the throttle grip. I got back on and continued 25 mi. trip to work setting off 4th of July fire works, no problem. Many days later I noticed if I lifted my hands off the grips it would start to wobble and slowly turn into a tank slapper, if I grabbed hold again I could calm it back down instantly. Took it to the dealer they checked it out and put a new tire on. I picked it up and checked it out, same thing. Brought it right back, they sent one of the techs out on it, he came back and said yes it does wobble into a tank slapper. They gave me some money back, basically charging me just for the tire and said that's the way it is ? I traded it at another dealer on a BMW K100LT, this tech must never have lifted his hands from the grips ? Something amiss but never found out what ?

[TopCatGr58]

Hey Greg,

Aside from either bending the TT, you may have also tweaked the steering neck/frame, just a degree or 2, but enough to throw it out of true balance!? The front wheel will be a little out of line with the rear, so like someone stated, either a pair of fluorescent tubes to see if the rear is in line with the front....or a laser level, or just rolling it across a hard surface that has a thin layer of sand over it and then inspect your tire tracks to see if they are inline or if you can see the rear off position from the front?? Hope it's the TT and not the frame neck!

T.C.

[BA80]

I thought of that too TC but I don't think that it was that much of force.

If you look at this pic that Tod took you can see a big plowed spot, right where whoever that is left leg is, where the front wheel grabbed on to the left bank of the ditch and tried to tear the bars out of my hands. I'm pretty sure that's where the forks got tweaked.



The bars were off to the right and the wheel to the left when the dust settled. Basically it was that force and me fighting back that did it.

[skids]

You probably tried this when you examined your forks, but do you see any slight turning of the wheel when you compress and pull up the forks. The bend or kink in the tube could be concealed.

[BA80]

No I haven't skids. But like I said, I'll be removing the forks this winter to examine them better. I need to put a little heavier oil in them anyway.

I'll disassemble the triple tree then too. Haven't touched it in about 5 years.

[Eveready1100]

The quickest way I've found to check the fork alignment is to get a small sheet of glass and lay it across the fork tubes above the lowers. That'll tell you in a second if they're twisted if the glass can wobble. If it sits flat against both tubes, they should be ok.

[BA80]

The quickest way I've found to check the fork alignment is to get a small sheet of glass and lay it across the fork tubes above the lowers. That'll tell you in a second if they're twisted if the glass can wobble. If it sits flat against both tubes, they should be ok.

That's actually how I did it when I straightened them up. Not glass but with a good flat piece of wood.

[jetmechmarty]

How flat can a piece of wood be? I'm sure you can understand how that sounds.

When you get those forks all apart, that might be a good time to upgrade. You mentioned you had cupping in the front tire. I don't. Ya know what I mean, Vern?