GIXXER CHATTER

[Eddie#200]

Well, I try to rev match, but I might not have been doing it too well in that particular corner.  I had problems with it all weekend.

I still think the GSXR is not as forgiving of not getting the RPM's just right as my R1 was.

If I don't get the rev match right during the downshift my 99 GSX-R600 will chatter.  I found being more deliberate with the throttle blips helpped me.

[OmniGLH]

Yes... rev matching will stabilize the bike a lot.  The gixxer's throttle response is kinda slow compared to other FI bikes (not sure what year your R1 is... but the '02 has incredible response...) You've REALLY gotta stab the throttle hard.  Plus, you want to make sure you downshift quickly.  Since I usually pit along the end of the front straight at BHF, I hear a LOT of Am's coming down on the brakes, grab the clutch, motor drops to idle, then they click down, and then they drop the clutch.  So you hear a lot of "bbbddddddddddd" as the back end is bouncing all over the place, and the engine is trying to brake.  You want to be swift at it... your rev match should really only take as long as you need to move the shifter.

[r1owner]

Since I usually pit along the end of the front straight at BHF, I hear a LOT of Am's coming down on the brakes, grab the clutch, motor drops to idle, then they click down, and then they drop the clutch.  So you hear a lot of "bbbddddddddddd" as the back end is bouncing all over the place, and the engine is trying to brake.  You want to be swift at it... your rev match should really only take as long as you need to move the shifter.

Come on now Jim, you've seen me ride... I'm not that[/i] bad am I?

[OmniGLH]

Come on now Jim, you've seen me ride... I'm not that[/i] bad am I?

Nononono... I was just showing an extreme example.  Usually the guys I see doing it THAT bad are the first-timers (guys who took the Breuer school the day before.)  They usually catch on pretty quick... but I bet most of them still don't do it quickly enough, and see this rear-end chatter everybody talks about.

[Super Dave]

Yeah, the GSXR's chatter so badly by design that Yates was barely able to finish races... :o.

Yates' fork internals have no relationship to the one's that are available to us.  Potentially, were talking about his having forks that have internals worth more than what we pay to get ours off the show room...

[sdiver68]

Just teasing about Yates....  ;)....I knew you couldn't let that one go.  Hey, if I take one of your classes next year I don't know if you'll be able to separate the smart alek from the serious  ;D

[Bam55]

Okay guys, guess I should have said, I am a top ten expert in Mid-West racing and I've won alot of races. I also am a four year Vision Sports Instructor. Does that make me special, HELL NO!!! My point for my original question was to see if any of you knew some simple way to deal with it, bent rotors, not rev matching, change my race lines, whatever.  I broke a 1:14 the last time at B-Hawk, still not enough to win but the chattering under hard braking in 1, 4, and 7 is so unsettling :o that it ruins the turn in then inturn ruining the exit speed. The tires I use are Pirreli/Metzler.
   None of those things have any bearing on what Dave and I worked on the two years of owning the GSXR's Dave admitingly pointed out what we worked on with this chattering, this question was not to see if you could help me fix it, it was to hear some input and see how many people new about suspenson. A couple of the early guys were on to this when they just said stuff about adding some compresion or rebound. Bent bent rotors?? :-/ I Give some of u credit though;)Keep on Racing!!!! say it with me Super Dave............I LOVE RACING...... I WILL NEVER QUIT..........I LOVE RACING......I WILL NEVER QUIT.......

[OmniGLH]

Huh... well... then I have no idea what you're talking about  :) I run consistent 18s at BHF, so maybe that's not fast enough yet to notice it? *shrug* All I know is, I've never really noticed it.  My last guess would be that it's the track...  tho I imagine you would've ruled that out by now... not to mention, if it were the track, then Gixxers wouldn't be the only ones who experience it.  I'll be the first to admit that I don't know a DAMN thing about suspension setup  8)

Ask me again mid-way through next season, hopefully I'll have cut a 15 or two, and learned a little bit more about suspension setup.. maybe then I'll have noticed it  :D

[bfkidd]

Ok, yes mine did chatter like crazy when it was new. Then I destroyed that one and got another one. So I have had 2 '01 750's. And yes, they both chattered like crazy under braking going into corners. Both time the forks were done to spec and the shock was shimmed. What fixed it? I took the bike to Eric Gray and he fixed it. Was it the Penske? Was it the GMD setup? Dunno. But I had to really work hard before to keep it under control, and now I am lazy with my downshifts and my blipping and it never does it! Well, under very rare circumstances it feels like it might want to start, but it never does. I am very thankful that I don't have to deal with it anymore.

I believe it has to do with the shock more than anything but that is just my guess.

Yes these bikes do it like crazy until it is fixed. It isn't bent rotors and it isn't riding technique. It is just something that has to be tuned out. Believe it!

[Super Dave]

Just teasing about Yates....  ;)....I knew you couldn't let that one go.  Hey, if I take one of your classes next year I don't know if you'll be able to separate the smart alek from the serious  ;D

Serious?  Me?  Dave like to play...

[Bam55]

Dave (Rosno) ;D and I figure, mind you this is a guess after making a quite time consuming change, if the chain has less length to the adjusters it (Chattering) seems alot more drastic. We tried the same gearing with less and more chain availability, with the adjuster toward the back, taking the wheel base wider, it seemed non-existant. Find out if your friend (ERIC GRAY) did this or maybe what he did do to remedy this wonderful rear wheel chatter. Oh yeah, my suspension has been done since the first time I ever rode the GSXR ;)

[r1owner]

Dave (Rosno) ;D and I figure, mind you this is a guess after making a quite time consuming change, if the chain has less length to the adjusters it (Chattering) seems alot more drastic. We tried the same gearing with less and more chain availability, with the adjuster toward the back, taking the wheel base wider, it seemed non-existant. Find out if your friend (ERIC GRAY) did this or maybe what he did do to remedy this wonderful rear wheel chatter. Oh yeah, my suspension has been done since the first time I ever rode the GSXR ;)

Hmm...that's interesting.  It kind of validates the R1 theory of a longer swingarm then.  Cause the R1 never seemed to ever want to do that.  I remember that one of the R1's revolutionary traits (for streetbikes) was the longer swingarm.