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Discussion Starter #1
I think I've narrowed down my handling troubles to rebound damping at the fork (may also be oddly worn 10,000 mile tires; I've noticed that I've been running off the side of the tire :eek:). I have emulators with 20 wt oil. Is there a way for me to change the damping (I imagine lighter oil for less damping)? I can't remember if I have too much or not enough. I'm thinking not enough. The front end feels like it is all over the place when I turn in hard, and then it won't settle down through the corner when I lay it over. It didn't used to be like this. My dealer noticed I was bottoming out the forks (I weigh 140), so he changed something but I'm not sure what.
 

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In your setup, damping is controlled by oil weight. Heavier oil = more rebound damping (not more rebound!)
 

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Bottoming out at 140#? Running off the edge of the tire? Where are you riding like that? On the track I hope.

If you are running out of tread then the front end will definitely be squirrely. Try hanging off more to the inside. Move your head and shoulders to the inside also. This will stand the bike up.

Check the front end sag. Total sag should be 30 to 35mm. It may be that your springs are sagging out, although I haven't heard of quality control problems with the stock springs.

You may or may not have damping problems. Check the sag first. Try 15W fork oil. Inadequate damping in either jounce or rebound (or both) can make the front end skip to the outside, but if you're out of tread that's the most likely cause, and altering the damping will not help. It sounds like you are pushing very close to the limit.
 

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Discussion Starter #4
What gets me is that it changed after the dealer screwed with it. I think the bottoming comes from hitting a bump with the forks compressed (hard on the brakes). I don't consider that type of riding to be anything out of the ordinary. Stop for a deer once on a backroad. I still can't figure the tire thing out. The only thing I can figure is some of the roads around here are really crowned. As I'm not dragging anything I don't get it. I've not felt the front tire slide either (occasionally recently on corner entrances as the tire has gotten quite old and is giving up the ghost, but not enough to actually wear the tire down).

I think "the limit" is a pretty arbitrary place to define. Different limits on different roads. I don't want to open a major can of worms, but I am not riding nearly as fast on the street as I have at the track. I appreciate the feedback though. I decided 2 years ago in the mountains that I can easily go faster than is safe/reasonable. I limit hard cornering to those corners that I can see fully through.
 

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It would be nice to know what your dealer changed. Chances are he added more preload, changed the oil level, cranked up the preload on the emulators and/or changed the oil weight. Does it feel like the front end is riding higher than it used to? Do you know what weight of springs you have? If you've got the nose-high/tail-low chopper geometry thing going on, it causes all kinds of weird handling issues, including causing the bike to not settle in the turn and also sliding the front tire and running wide at the exit. You should think about maybe taking your forks apart and checking them out to see what you've got if possible.
 

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Nimbus said:
  The only thing I can figure is some of the roads around here are really crowned. .   
We've got a bunch of crowned roads around here and I can tell you that it will make your front end wander all over the place...especially on a turn.  Having said that, I think you should definitely move your fork oil weight down to at least 15 w.
 

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Discussion Starter #7
jarelj said:
It would be nice to know what your dealer changed.  Chances are he added more preload, changed the oil level, cranked up the preload on the emulators and/or changed the oil weight.  Does it feel like the front end is riding higher than it used to?  Do you know what weight of springs you have?  If you've got the nose-high/tail-low chopper geometry thing going on, it causes all kinds of weird handling issues, including causing the bike to not settle in the turn and also sliding the front tire and running wide at the exit.  You should think about maybe taking your forks apart and checking them out to see what you've got if possible. 
I am running stock springs (remember, I'm pretty light). I don't feel the bike rides any higher than it did. The problem doesn't exist on slower turns, just higher speeds. I can really hammer 50 mph turns and the bike stays on line with no instability. Once I hit about 70 mph though, the problem crops up. There is one exit ramp with fairly evenly spaced irregularities (bumps, seams, depressions or similar) and it totally causes the front end to act up (and I'm not pushing it either, leaned over at a relatively modest angle). Otherwise life is great.
 

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AHA! Aging tires could be part of the problem. Tire rubber hardens as it ages. Crowned roads change the geometry of the bike/road combination. The worst combination is a negative crown on the outside of the curve. In essence it is just like making the bike lean farther over. The limit I referred to above is the tread limit on the tire. If you have zero chicken strips then you could be at the limit, or you could be going past the limit. Once you're past the tires lean limit you lose contact area rapidly with any additional lean.

Check your sag yourself so you'll be sure, check to see what weight oil the dealer added. As I said, I weigh 165# in gear and I've never bottomed the forks. Not even potholes.
 

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andyauger said:
Aging tires could be part of the problem. Tire rubber hardens as it ages. Crowned roads change the geometry of the bike/road combination. The worst combination is a negative crown on the outside of the curve
I suspect (but cannot prove) this is the combination (maybe also with the friction loss of hitting a tar strip) that sent me "Supermanning" in one direction while my bike went into a guardrail in June. My front tire (which let go) was old.

Nimbus: If you weigh 140 (w/o gear, I assume) then you + gear + bike + gas = ~>550 lbs. According to the traxxion dynamics chart http://www.traxxion.com/technical.springrate.shtml your stock springs (.7 kg/mm) are way to light even if you were an anorexic 10 year old girl.
Maybe it's your springs.
 
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...all excellent advice.

At 10,000 miles you must be almost ready for a new front tire. You're gonna replace it soon anyway, why not swap it out now, before you change a bunch of other stuff? You had a configuration that you were comfortable with- I would look for worn components before you stray to far from your original setup.

:)
 

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Discussion Starter #11
I'm betting on the tires too (because my wife would burn the bike if I told her I wanted new springs any time in the next year or so). The 020's are great, but after about 8,500 miles, I start rapidly losing confidence. It's no fun wondering if your tires are too hard for the next corner. They have begun to scallop (visibly) and I've been living with it. The SV is odd in that it seems to really ride the front tire. My front is worn nearly down to the wear bars and has negative chicken strips. The rear tire has about 1/8-1/4" strip.

Thanks for the feedback everybody. I had ordered a set of Z6's on Thursday when I started this thread, so I expect them soon.
 
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