Front end chatter

[swanman]

Had a great time at Puke today. However never before have I had so much front end chatter. I first got it breaking into Castrol so much so that I ran onto the grass. I then increased front preload and changed my entry into Castrol, no probs. However braking hard from 270 down at the end of back straight would have my front end chattering like mad. So bad I had to release the brake and reapply it a number of times to clear it before I could take the hairpin. What's going on there? And how do I stop it happening?

I have had it happen to me a couple times on the road too.

[geoffm]

Had a great time at Puke today. However never before have I had so much front end chatter. I first got it breaking into Castrol so much so that I ran onto the grass. I then increased front preload and changed my entry into Castrol, no probs. However braking hard from 270 down at the end of back straight would have my front end chattering like mad. So bad I had to release the brake and reapply it a number of times to clear it before I could take the hairpin. What's going on there? And how do I stop it happening?

I have had it happen to me a couple times on the road too.

Are the forks bottoming out? Tie a cable tie around the shiny bit and that will tell you how far the forks are moving.
What weight oil are you running? How much? decreasing the air gap will increase the spring rate at the end of the travel without making the beginning harsh.
Do you have adjustable damping - what settings?
Geoff

[swanman]

Are the forks bottoming out? Tie a cable tie around the shiny bit and that will tell you how far the forks are moving.
What weight oil are you running? How much? decreasing the air gap will increase the spring rate at the end of the travel without making the beginning harsh.
Do you have adjustable damping - what settings?
Geoff

I am sure the the forks are bottoming out. The oil I am running is standard OE stuff, the bike is only 6 months old. I am sure I can adjust the problem out, as I have adjustments for rebound, compression and preload. The question really is what adjustments to make?

[FROSTY:Me]

What tyre pressures are you running.? could be that diddn't help

[swanman]

I decreased pressure to 2.2 on the front, 2.5 at back. The tyres seemed to behave well, good grip, minimal sliding.

[FROSTY:Me]

gee mate it doesn't make sense that a modern sports bike would be that soft in the front end. It almost sounds like the forks are too soft for the track.
Have ya done the sag test ?
Its funny it should be chattering in castrol -its such a smooth open corner now.
The hairpin I can understand

[StoneChucker]

I'm so glad I'm not the only one. I've had the same problem for ages, but only in a certain situation. Downhill corners, from memory ONLY right handers... It's so bad that when it comes I have to stop braking, and re-apply. My best description is a jackhammer... I've had it in to Sawyers twice now, and they say nothing is wrong...

Maybe it IS just settings, but like you I have no idea. Come to think of it, it probably is settings, since I'm alot heavier than the rider it's set up for. I think we need to get it sorted soon, it's a bloody big hazzard. As you say, I've almost crashed because of it (ran out of road while releasing break, and fighting the jackhammer).

Weird thing, I have no problem on the straights, and in uphill corners... Don't you just LOVE these types of issues??

[Sensei]

Here are some Setting's for a 04 R1
Front
Preload = 3 lines showing
Rebound =7 clicks out
Compression =9 clicks out

Back
Preload 8 of 9
Rebound = 21 clicks out
Compression = 7 clicks out

Note you can drop the Fork tube to 5mm through the Triple clamp as well if needed .Have setting's for 97 -04 R1's
Have used the setting off this site to set up my GSXR1000 & are excellent


SENSEI

[StoneChucker]

Thanks Sensei.

But don't you have to have Sag set for the other settings to be of much benefit? Or will those settings help in the meantime, until one were to get their sag set?

I'm probably going to pay someone to do it, would take me too long to fiddle with settings I know nothing about

I have seen pages of setting before, but never really got around to changing them. Mostly because I'm inherantly lazy, and it would take up time I could be sleeping or riding

[swanman]

Here are some Setting's for a 04 R1
Front
Preload = 3 lines showing
Rebound =7 clicks out
Compression =9 clicks out

Back
Preload 8 of 9
Rebound = 21 clicks out
Compression = 7 clicks out

Note you can drop the Fork tube to 5mm through the Triple clamp as well if needed .Have setting's for 97 -04 R1's
Have used the setting off this site to set up my GSXR1000 & are excellent


SENSEI

I'll try these settings, they certainly would appear to be quite stiff. Unfortunately in order to replicate the issue I need to brake hard from 270kmh, hmmm. Wonder if that would stand up in court. Do you have the site address for these settings? Ta

[swanman]

Yep this is the same problem for sure. I weigh just under 90kg so that might have an effect too. Funny that in the journos' write ups there is no mention of it. I reckon you can dial it out so I'll try Sensei's settings, am just concerned that stopping the front end chatter may make the bike harsh or too firm. We'll see.

[StoneChucker]

let us know how you get on won't you?

[Sensei]

Yep WWW.Sportrider.com go to suspenion setting area
SC have left my GSXR at standard Sag setting's which is easily checked then put the setting's for my bike onto it . Put 2 less Rebound & left the rest .
SENSEI

[pritch]

The following link has some good information bearing in mind it was obtained on their bike with their rider etc etc. But if you find yourself lost it might be a place to start...

http://www.sportrider.com/bikes/146_susp_settings/

[Two Smoker]

You have to set the sag to about 23-25mm front and rear... once that is done, you can play with the preload and rebound...

Sounds like you need to adjust the preload Swanman, then increase the dampening slightly... But on the track its different. I have my ZXR400 hard, i wouldnt like to ride it on the road as the suspension is set up now...