ZX10 front end shake - trackday - why?

[Big Dog]

it only happend at my last track day after turn 5. back straight. its pretty flat. i am in second gear at turn 5 and i speed up violently and change to 3rd and change to 4th. i think my violent change could be the problem. but that i thought was a given. Because i am accelerating very fast the front sort of comes up and gets light. (the front didnt actually come up). And then i get a shake. I think this is the only place i am accelerating the hardest. I thought the steering damper revalve solves that issue.

A damper only dampens.
If you completely removed all head shake by turning the damper up so far head shake was impossible you would replace the head shake with what feels like squirming from the rear.

All that energy has to go somewhere.


Stupid phone / Tapatalk, apologies in advance.

[jafa21]

This is along the lines I was thinking. The correct suspension settings are not written on stone tablets. If the rider puts on, or loses, weight that will effect things. If the ability of the rider improves so that he is going faster that will also effect things. So, of course, will damage to the bike.

I have here a copy of "Sportbike Suspension Tuning - How To Improve Your Motorcycle's Handling and Performance" by Andrew Trevitt and I commend this work to anyone who wants to understand their bike's suspension. (No not my copy, y'all can buy yer own.)

The book contains a suggested course on how to fully understand what effect the various suspension adjustments have. It also contains a trouble shooting guide.

"High frequency headshake on smooth pavement. Likely cause: insufficient trail
Add trail by lowering rear ride height, reducing rear preload, lowering the fork tubes in the triple-clamps, adding front preload, or decreasing triple-clamp offset."

Those suggested solutions are all separated by an "or" not an "and". When altering settings it is best to change just one at a time otherwise you won't know which change worked.

If I may make one other suggestion? Ask a friendly mod to move this to the "Frame Suspension and Final Drive" forum where it's just possible your thread may attract the attention of people who can help, anyway it should attract less attention from people who almost certainly can't.

this seems like my problem -
"High frequency headshake on smooth pavement. Likely cause: insufficient trail
Add trail by lowering rear ride height, reducing rear preload, lowering the fork tubes in the triple-clamps, adding front preload, or decreasing triple-clamp offset."
how do i solve it i cant do any of the above on my own. so robert taylor then ?

[jafa21]

Seriously though with the track conversion from road what tyres are you running now??? I remember my GSXR being dead stable on road tyres but with proper triangulated track/race tyres it scared the shit out of me at Pukekohe and became a liability on the road....

same tyres as before. Q3s. i had them on before converting the bike

[jafa21]

And what bits came off? Enough to affect the weight bias?


Stupid phone / Tapatalk, apologies in advance.

all the fairings, headlight, indicators, rego plate, mirrors. Speedo is still there.

[jafa21]

Chances are he has already spent $1000s and with all the further advise on here likely to add up to thousands more which may or may not solve the problem it could very well be cheaper to buy a new bike.

i dont want to be rude cos i dont know you or had any past experience with posts. But i agree with the other guys here. Please stop commenting.
I paid $15 bux for somebody's time (15 minutes) to set up my suspension.
I definitely do not need a new bike.
Every rider is different and every track is different. It doesnt mean i need a new bike.

[Big Dog]

i could be more aggressive at the back straight - very possible.
i think i might be bit stiff after the crashes.
i havent gained or lost weight.

i do feel its my input thats making it like this as it doesnt happen everytime. but i thought if i get damper revalved no matter what i did the damper will prevent from shaking.
The above comment probably sounds stupid to some. but i dont know what i am talking about so i thats why i am asking here

If I were you I'd go for a ride on another bike or toe and get someone who's opinion you trust to ride yours. If the problem persists across multiple bikes it is likely you. If the trusted rider has a problem on your bike it is likely your bike.
The trouble with track bikes is to properly assess a bike you need to ride it.

Based on your descriptions and having not seen you ride or ridden your bike I'm leaning in favour of rider input being the issue.

This may sound daft but either sit on your bike or a bicycle while it is being supported by friends ( or willing participants if friends are currently in short supply ) with your feet up and mimic the action you know you should be taking.
Does the bike wobble?
Now mentally prepare yourself for a fast right hander with someone coming round the outside.
Is that different?
Tight left into a right into a straight, how is that different?

Hint: if your turning the bars the bike should flop in the direction of the countersteer by the amount you turn the bars. It should be smooth. If you can manage to isolate your movements to just the throttle and gear movements you will get a better picture for how they are affecting your steering.

Even leaning forward more often during cornering changes the outcome of your steering inputs because it changes your weight bias, makes movements in your arms translate more efficiently to the bars and changes your perception of how far you are twisting the throttle. Not to mention changing the level of aggression you natively apply to other inputs.

If you watch the stars of the Moto-GP you barely see their inputs until they get stressed. When you start seeing their inputs you start seeing the bike wobble all over the show but they are not going any faster. If they do this too long they make the crash reel.


Stupid phone / Tapatalk, apologies in advance.

[Big Dog]

all the fairings, headlight, indicators, rego plate, mirrors. Speedo is still there.

So more from the front than the rear plus a change in the purpose?
Keep I mind if you were still road using it when Rob set it up he would have set it for the road track bias you discussed.
Sounds to me like you need to isolate is this a problem with you or the bike.
Tune accordingly.


Stupid phone / Tapatalk, apologies in advance.

[madbikeboy]

i dont want to be rude cos i dont know you or had any past experience with posts. But i agree with the other guys here. Please stop commenting.
I paid $15 bux for somebody's time (15 minutes) to set up my suspension.
I definitely do not need a new bike.
Every rider is different and every track is different. It doesnt mean i need a new bike.

LOL, awesome.

I read some notes that I had from riding ZX10R's from 2006/7/8/9, they included "front end lively, and wants to tuck". I can recall that they were frisky, and that the steering damper had a lot of effect on the bike.

There's not enough information yet to make a determined call - check the basics like (as someone has pointed out before) rear ride height (check for washers on the rear shock, someone might have added ride height), alignment, fork heights, alignment. It's also possible to remove the forks and check them for straightness. Sometimes the forks don't look bent, but even a small amount of stiction will cause problems. Once you've established everything is straight and true, and you don't have 30mm of fork through the yokes (don't laugh, I've seen it), then you can start to isolate. Steering damper exchanged for the stock one would be my first move.

Small changes in suspension make huge differences. Again, there's a reason why everyone goes to Robert Taylor and Shaun Harris. Both are very experienced at suspension set up.

Finally, as everyone has already commented, rider inputs make a big difference - gripping the tank with your thighs (use stomp grip) and holding the bars very relaxed is how I ride; this stops unwanted inputs going through the bars. It also means small headshakes don't end up in uncontrollable tank slappers (for the most part, I've had very high speed slappers that were interesting to ride through).

Good luck.

[aderino4]

https://www.youtube.com/watch?v=zqpVtJQxFSc


Worth watching..

With the weather being really good recently; you may have inadvertently be more aggressive on the throttle, therefore rear squats more and thus the head shake.

I noticed the 2 videos were in April and November which have cooler weather.

More heat = stickier tyre = more grip = less rear wheel slide/give = more rear end push = less weight on the front = more prone to head shake

Dont' mask the issue by turning up your damper.

[cs363]

@cassina Please stop commenting.

Best advice ever on KB.





Sadly, it'll be ignored.

[Big Dog]

Chances are he has already spent $1000s and with all the further advise on here likely to add up to thousands more which may or may not solve the problem it could very well be cheaper to buy a new bike.

Chances are if he buys more hardware to fix a problem he has not isolated it will be very expensive.
That includes buying a new bike before confirming he is not the problem.

Many problems can be solved by adjusting the most important nut on the bike. The one that joins the seat to the handlebars.



Stupid phone / Tapatalk, apologies in advance.

[sugilite:Me]

it only happend at my last track day after turn 5. back straight. its pretty flat. i am in second gear at turn 5 and i speed up violently and change to 3rd and change to 4th. i think my violent change could be the problem. but that i thought was a given. Because i am accelerating very fast the front sort of comes up and gets light. (the front didnt actually come up). And then i get a shake. I think this is the only place i am accelerating the hardest. I thought the steering damper revalve solves that issue.

My personal feeling is it is not so much a suspension setup issue, more likely a possible slight misalignment (and a wee bit of ham fisted riding). So as others have suggested, loosen the triple clamps and then string line the wheels to at least get a basic idea if things are straight. (plenty of youtube videos on how to string line).

I watched the two videos you posted and the following is not a criticism (and you may already know anyway), more an observation. The first one where you lose the rear was to much gas for the tyres you are running. You can hear the tyre start to spin but you did not do anything to mitigate that. The 2nd one was a confidence one. If you are going to pass someone on the outside, you have to really commit and not second guess yourself (and have the skills to back the move). Your acceleration was such you could of easily slipped past him even though he was drifting.

You have chosen a very, very tough task master to learn your track skills on. I have raced ZX10R's at the top level, track ridden and road ridden them. They reward a curious combination of aggression mixed with finesse. You need to dominate the bike in a physical way but apply that strength and domination with a smooth fluid style.
I have worked with a guy at a track day that rides a 08 10R and I focused on initially slowing him down and focusing him on a fluid smooth style, looking through the corners and focusing well ahead. He was convinced he was not going much better until the organizers came to his pit saying he was now too fast for the group he was in and bumped him up to the next one.


Assuming your bike is straight, I'm pretty sure your not riding past the limits that your current setup would allow. So yes, focus on your riding, do some work with coaches and you will be flying in no time.

[jafa21]

My personal feeling is it is not so much a suspension setup issue, more likely a possible slight misalignment (and a wee bit of ham fisted riding). So as others have suggested, loosen the triple clamps and then string line the wheels to at least get a basic idea if things are straight. (plenty of youtube videos on how to string line).

I watched the two videos you posted and the following is not a criticism (and you may already know anyway), more an observation. The first one where you lose the rear was to much gas for the tyres you are running. You can hear the tyre start to spin but you did not do anything to mitigate that. The 2nd one was a confidence one. If you are going to pass someone on the outside, you have to really commit and not second guess yourself (and have the skills to back the move). Your acceleration was such you could of easily slipped past him even though he was drifting.

You have chosen a very, very tough task master to learn your track skills on. I have raced ZX10R's at the top level, track ridden and road ridden them. They reward a curious combination of aggression mixed with finesse. You need to dominate the bike in a physical way but apply that strength and domination with a smooth fluid style.
I have worked with a guy at a track day that rides a 08 10R and I focused on initially slowing him down and focusing him on a fluid smooth style, looking through the corners and focusing well ahead. He was convinced he was not going much better until the organizers came to his pit saying he was now too fast for the group he was in and bumped him up to the next one.


Assuming your bike is straight, I'm pretty sure your not riding past the limits that your current setup would allow. So yes, focus on your riding, do some work with coaches and you will be flying in no time.

Hi thanks for the tips. I definitely agree both the crashes could have been avoided and due to my limited skill i crashed. Yes the bike is very violent and i need to be less aggressive and be more smooth before i can get faster.

[mossy1200]

ENJOY

Crash 1 - lowside - turn4
https://www.youtube.com/watch?v=RiWRuadMM2g

Crash 2 - just before turn 5
https://www.youtube.com/watch?v=xmb7...ature=youtu.be

Don't look like big hits but at the end of the first looks like clipon hit the track edge. Possible triple clamp not aligned now. It would need be off much to cause issues when the front wheel is light.

[jafa21]

Don't look like big hits but at the end of the first looks like clipon hit the track edge. Possible triple clamp not aligned now. It would need be off much to cause issues when the front wheel is light.

it wouldnt need to be off much or it would. sorry bit confused