GSXR handling. Yes another setup question.

Request for opinions.

The subject is a 2000 GSXR 750 with a heavy slow rider.

The problem is that just after the apex, the front feels like it is going to tuck in and down.

Turning in feels good. Exit is fine. I have made sure to keep rolling throttle on and not to input direction changes at that point.

Does this sound like a setup problem or is it pilot induced?

Traxxion forks, 10 mm above the clamp. Pictures from the track show about 2" left before bottoming in a tight turn. Sags about 25 mm total with rider.

Rear Penske double clicker, unknown spring rate, about a 1/4" of thread showing above the lower clevis and another 1/8" spacer on the top mount.

Metzeler RS1 front/ Metzeler RS2 rear. 29/28 psi.

 

More info.....

Rider Weight ..
Spring Rates
Free Sag
Static Sag
Oil Weight
Oil Level

Ride Safe.........

 

Try shifting your weight forword in the turn if you're not doing that allready. Better suspension setup may help too.

 

sounds like race tires are in order

 

Sorry,

I have no idea about the spring ratings or the oil weight.
The bike was already setup like this when I got it.

I weigh about 230# depending on how many Happy Meals I've had.

I thought increasing the weight forward would make the front have more of a tendency to wash out. Like rolling off of the throttle would.

It is race tires. Metzeler Rennsports conditioned by Chickenhawk warmers.

Now that I think about it, I'll try to get one of the suspension pro's to look at it at the GNF.

Thanks for the response.

 

More than likely you are too heavy for the current setup. Unless the previous owner was within about 15lbs of you weight you'll probably need stiffer springs and different suspension valving. You're right about too much weight over the front can cause a washout but not as much as having your weight too far rearward. You need to find the right placement of your body to keep both wheels doing what you want them too. Try experimenting with your riding position and see how it affects the traction/handling. You can get a pretty good idea about whether the spring rate is right for you by checking the free sag against the weighted sag. I think Traxxion, Racetech, Ohlins, Sportrider Mag, etc. have sag setup instructions on their websites.

 

Guesswork....????

Ok... you have Traxxion Forks and a rear penske, they are good suspension but probably not adjusted for your weight.....

Sag Figures are needed to have guideline because your problem is suspension and/or geometry.

Of course you can achieve a correct total sag number with the preload adjuster, but this number don´t tell if the spring rate is correct.

First of all your springs MUST suit your weight(that´s why Sag numbers are so important), anything else is just guesswork.

Ride Safe...............

 

Thanks for the input.

I have decided that I have wasted enough time guessing about setup.

This time I'm going to put the old "do it yourself" pride aside and get professional help.

 

Metzeler has not made race tires in over two years. Try some new tires

 

I thought Rennsports where the same as Supercorsas but with different tread pattern?

 

You are correct. The same exact compound just a different tread pattern

 

Yes they WERE the same just have not been made in over two years. All Race tires from Metz/Pir are now Pirelli branded only.

Metzeler = Street tire
Pirelli = race tire

 

I believe your incorrect

I found many websites still selling the tire. I called this one and they said they still get these tires from Metezler. True, Pirelli merged with them but to the best of my knowledge they still make the tire.

http://motorcyclepitstop.com/mivastore/merchant.mv?Screen=CTGY&Store_Code=004&Category_Code=metzrace

 

Call a race tire dealer if you don't believe me. I prefer tires that are fresh, plus I generally run Michelins.

When the tires get old you find they are sold to the discount centers and that is what motorcycelpitstop is.

 

10 mm out of the top of the tirpple sounds to much. You probably have to short of trail and causes it to feel like it wants to tuck the front. Try 5mm out the top, or even flush.

 

I think (hope) that I have discovered the culprit.

Traxxion's web page has some excellent information. In one article Max advises to use a front stand instead of just pulling up on the bars for measuring fork sag.

A half hearted pull up resulted in semi normal measurements. Using the stand showed that there was waaaaay too much sag in the forks. To the tune of 38 mm for the bike alone. Add another 11 to 12mm with rider.

I screwed the preload caps in and it seems to have a more reasonable measurement now.

The rear measurements were pretty close to the recommended sag settings to start with.

I am still planning on having the bike checked by a professional though.

Thanks for all of the suggestions.

 

It sounded like the front did not have enough spring in it.

The guy I am working with right now is running 8.5 mm sticking out from the top clamp and the rear at 340 mm.

He weighs 210 lbs geared up and is using 1.0 springs in the forks and a 450 in the rear.

 

I know that the rear spring has 450-7 on it.

I have no idea about the fork spring rating. Even with the preload adjusted down, they still sag a little bit more than most people recommend.

It's got to be better than it was.

 

But what if that is a good as it gets?

 

Then I guess that I'll just have to deal with it.