Honda CBR 600RR Forum banner

1 - 19 of 19 Posts

·
Registered
Joined
·
223 Posts
Discussion Starter #1
Got my first track day of the year next week and last time out I was bottoming forks out on the brakes. There on setting 3 turns from (soft) only way I can explain it. Lol out of 10 iirc. What do you guys recommend? I'm only 66kg so was thinking of adding 2 turns for the first session.
 

·
BOTM winner 03/15
Joined
·
2,308 Posts
What measurements are you getting when you set your sag?
 

·
Registered
Joined
·
223 Posts
Discussion Starter #3
I'm not 100% as I got it setup by a professional and he never gave me the settings. He came 5th at the Isle of Man TT so I trusted him. Lol but i set preload to 3 and got 28mm of sag and he said he didn't have to adjust preload so I'm guessing it's somewhere close to that.
It's definately setup on the softer side for the road.
 

·
BOTM winner 03/15
Joined
·
2,308 Posts
Static sag sounds in the right ball park for the front.

If you're running stock springs and the preload is set properly so you're achieving the right static sag, I'd be amazed if you're bottoming out the forks when you're weighing 66kg's.

You might want to check your compression damping and increase it if necessary? Also, when was the last time the fork oil was changed? What viscosity is it? Is the air gap set right? Etc... Quite a few variables to check but if your sag is set correctly at the current preload, increasing preload probably isn't the answer.

If you were heavier I'd consider the possibility that the fork springs were not stiff enough for your weight, but at 66kg I don't imagine this would be the case.

This is a good basic guide to suspension setup and may help you fine tune your ride :)

http://www.gostar-racing.com/club/motorcycle_suspension_set-up.htm
 

·
Registered
Joined
·
223 Posts
Discussion Starter #5
Forks were def bottoming out and clunking. It's a 2010 and I've never changed the fork oil etc but works fine on the road I just think the nose dived too much under heavy braking on track. There are bumps in the braking area which obviously doesn't help.

I just don't want to mess up my road setup as it's pretty spot on for the roads I ride.
 

·
BOTM winner 03/15
Joined
·
2,308 Posts
I just don't want to mess up my road setup as it's pretty spot on for the roads I ride.

Just take a note of your current settings and then change one thing at a time, noting its effect as you go. It's not hard to go back to what you had originally. See the link I added in my previous post for guidance on what changes you can make.

You could also see the suspension guy at the track you're riding. They'll be able to help I'm sure.
 

·
Registered
Joined
·
223 Posts
Discussion Starter #7
Cheers. Yeah there isn't any tyre or suspension guys at this track. there's a few quick lads I could ask though.
 

·
BOTM winner 03/15
Joined
·
2,308 Posts
Well, I weigh 80kg and I've never bottomed out my forks under braking...stock springs fitted.

My static sag is set at 22mm via the preload. Can't remember the comp/rebound settings off the top of my head but I have them written down in the garage.

Honestly, 5 years is long enough to warrant fresh fork oil so you could start with that. That'll allow you to set the correct air gap too and you'll notice an improvement for sure. Set the static sag at 25-30mm, and put comp/rebound in the middle of the adjustment range and work from there. It certainly sounds like you don't have enough compression damping at present.
 

·
Registered
Joined
·
223 Posts
Discussion Starter #10
The suspension guy (Ian pixie Patterson) adjusted everything since my last track day so it might actually be fine now. I just thought it was lack of preload causing it which I know he didn't touch as he said it was correct setting for me.

Just wanted it to be right this time as it hampered me last time. It's all day though so have time to change things.
 

·
BOTM winner 03/15
Joined
·
2,308 Posts
The suspension guy (Ian pixie Patterson) adjusted everything since my last track day so it might actually be fine now. I just thought it was lack of preload causing it which I know he didn't touch as he said it was correct setting for me.

Just wanted it to be right this time as it hampered me last time. It's all day though so have time to change things.

Ok, well if settings have been changed since your last track day then the only thing to do is to ride it and see how it feels this time out. Good luck mate, which track are you visiting?
 

·
Registered
Joined
·
223 Posts
Discussion Starter #12
It's a full day at teeside autodrome. I wanted donnington on the 2nd but couldn't get registered and croft is fully booked on the 20th so had no choice but teeside. I don't live too far away though so at least that's one good thing.
Good one to get back upto speed with.
 

·
Registered
Joined
·
223 Posts
Discussion Starter #14
Cheers if weather is good should be a good day. I'll post up some pics and videos if my mate borrows me his go pro.
 

·
Registered
Joined
·
3,968 Posts
Do you have different springs installed in your forks? Or are they the stock spring rates?
 

·
Registered
Joined
·
223 Posts
Discussion Starter #16
They are all stock as far as I'm aware. I'm 100% now that it's the compression not the preload that needs adjusting. After the straight it's really bumpy in the braking zone at the track I'm riding.
I'm also going to try and do my hard braking early then easing off as you go into the corner like the moto gp guys which I think would help.
 

·
Registered
Joined
·
966 Posts
If you don't weigh enough for the 1.0kg/mm springs already installed and your still botteming out then you need more compression damping. If the correct amount to keep you from botteming out makes the ride too bumpy to handle then you probably need to upgrade the suspension valving.

As a cheap band aid, raise the fork oil level.
 

·
Registered
Joined
·
111 Posts
66 Kg isn't too heavy for 1.0 springs unless you are doing expert race level times. Sounds like you don't have enough low-speed compression damping. You will need to increase it and deal with the bumps unless you want to get your forks re-valved. Alternatively, you could try to be less aggressive on the brakes and try to carry speed through the corner. Smooth application and trail all the way to the apex.
 

·
Registered
Joined
·
223 Posts
Discussion Starter #19
I was on track on Friday at croft and bike worked fine. Could of done with being stiffer but no bottoming out issues this time. I've actually bought a track bike now so RR is retiring from track duties as leyla fairings are too expensive if I bin it. Bought a aprilia rsv Mille as track only machine.
 
1 - 19 of 19 Posts
Top