GSXR1000 Suspension

zipster · 10-08-2006, 11:39 AM

I need some advice on my 2005 - GSXR 1000 track bike. I am totally bottoming out my suspension on the front end no matter what adjustments I make. I weight 205 lbs. I'm thinking new springs. Any thoughts? I’d like to stay with he factory front end. Not looking to spend insane amounts of money on it.

nig · 10-08-2006, 12:02 PM

Did you measure the sag etc..?

Springs and revalve should be less than $500.

zipster · 10-08-2006, 08:52 PM

Quote:

Originally Posted by nig

Did you measure the sag etc..?

Springs and revalve should be less than $500.

I did. I thought I had everything set up before my first track event with this bike. Here were the settings. I have cranked down on almost all the front settings since without any luck.

Front Suspension
F1. Bike on a stand with the Suspension fully extended =11.6" (295mm)
F2. Bike on the ground WITHOUT rider = 10.7" (273mm)
F3. Bike on the ground WITH rider = 10.2" (260mm)

Free Sag = F1-F2 = 0.8" (22mm)
Ride Height = F1-F3 = 1.3" (35mm)

Front Preload = 4 lines showing
Front Rebound Damping = 2 clicks from full stiff
Front Compression Damping = 13 clicks from full stiff

***********************************************************

Rear Suspension
R1. Bike on a stand with the Suspension fully extended = 19.6" (498mm)
R2. Bike on the ground WITHOUT rider = 19.2" (488mm)
R3. Bike on the ground WITH rider = 18.5" (469mm)

Free Sag = R1-R2 = 0.3" (9mm)
Ride Height = R1-R3 = 1.1" (28mm)

Shock Length = 325mm
Shock Stroke = 70 mm
Spring Pre-Load = 8 mm
Rebound damping adjuster = 14 clicks
High Speed comp. damping adj. = 30 clicks
Low Speed comp. damping adj. = 12 clicks

zipster · 10-08-2006, 08:55 PM

Here are the guidelines I followed...

nig · 10-08-2006, 09:15 PM

Well from those numbers the front springs and sag are fine. I'd crank up the compression some more and see if that helps. If still nothing I'd add a cap or two of fork oil to each fork.

I don't guess you've been inside the forks to check the oil level? Sometimes the people putting them together aren't paying attention.

Have you had somebody with some experience bounce your forks to look at the rebound? If it's too stiff you might just be packing the suspension over bumps and bottoming.

zipster · 10-09-2006, 12:20 AM

I just came back from a track day at Beaver Run and spoke with a few people that suggested the oil as well. I think I'm going to try that first. Seems like an inexpensive way to start and easy enough.

As for the compression, after the last event, I'm almost maxed out on everything. Can't imagine one more click is going to make enough difference. Plus correct me if I'm wrong but wouldn't it be better to set up the hardware so that all the adjustments are set somewhere in the middle of the range instead of all the way in or out? It would give me more flexibility at the track to make adjustments for varying track conditions, no?

GSXR RACER MIKE · 10-09-2006, 12:33 AM

Definately springs, the stock springs on that bike are rated for a 150 lb. racer.

Also as you get faster you will probably find you are carrying more speed thru the turns and not braking as much. That's the prob with big Hp bikes, you get going really fast on the straights, then have to come down from that speed and try and judge your entrance speed correctly. That's something that can be difficult enough with a lower Hp bike, and even more of a problem as you add Hp. I would definately get correct springs in there and then see what happens, if it's still a problem then adding a little compression damping like Nig said is excellent advice to combat your front end diving.

Also to be considered is your body positioning, you may be transfering alot of weight into the handlebars thru your arms if your doing it wrong. You want to scoot back in the seat a bit and grip the gas tank with your thighs when braking, this transfers your body weight into the bike further back on the bike and at a lower point. Once your doing it correctly you should be able to have your arms loose when braking, not tensed or locked which transfers your body weight to a high point way forward on the bike. You should also be able to have a very loose grip on the handlebars when braking as well, this will help prevent arm pump from happening.

I would also highly suggest upgrading the springs front and back to get proper balance on the bike, doing only front or back is not a good idea.

nig · 10-09-2006, 12:49 AM

Sorry, you had written you were 13 clicks out, thought there might be room to adjust.

Your fork could probably use a service. New oil, and the level set right. I can't tell you how hard it is because I've never worked on a USD fork. It should cost about $100 from a pro.

nig · 10-09-2006, 12:51 AM

Quote:

Originally Posted by GSXR RACER MIKE

Definately springs, the stock springs on that bike are rated for a 150 lb. racer.

His sag numbers are fine though, maybe they're not stock.

GSXR RACER MIKE · 10-09-2006, 01:05 AM

Quote:

Originally Posted by nig

His sag numbers are fine though, maybe they're not stock.

Hmmm, then maybe it's the weight transfer thing I suggested?

zipster · 10-09-2006, 08:38 AM

Funny you should mention that. I had some video shot at the track and you are correct, I am using nothing but my arms during braking. I picked up some Stomp Grip and will be putting that on for the next track day.

Funny thing is I was told by an instructor many years ago to set up for your next corner long before entering it. Meaning, hang off during breaking so that you do not have to shift or slide on the seat while entering into it or while in the turn. By doing so, I end up not using my legs AT ALL during breaking. I will focus on staying in the saddle a little longer next round. My arms are very fatigued after only 5 laps.

I also noticed my position while riding through the turns is off as well. My body position says "GO" but my head still say's "NO" and still stays square over the tank. After some advice from an instructor, I started forcing myself to poke my head as far forward and keep it as close to the tank as possible. I felt very uncomfortable at first, but what a difference it makes. I immediately picked up considerable corner speed and felt like I was hitting the entrance, apex and exits with much more precision.

The difference in riding position is clear when looking at these two images. I am barely leaning forward at all! (Slow me on the left / Fast guy on the right)

jk750 · 10-09-2006, 11:27 AM

Stomp Grip is amazing stuff.

nig · 10-09-2006, 12:09 PM

Yeah, I hate riding without it.

You are supposed to shift your body before you brake though. Just squeeze the bike with your legs, the grips will help.

96SNAKE/03RR · 10-09-2006, 12:15 PM

Hey! I was at Beaverun this weekend too.

When I first bought mine this July, I was so frustrated with the fork chatter, I thought I made the wrong choice buying it after taking one ride on it. After I took some rebound damping out, it got much better on the 2nd ride but I knew I was going with Ohlins cartridges before getting the bike on the track.

Not that it's necessary to get the cartridges, because it isn't. There are just as many people on revalved stockers that have great success. Imo though.. I wouldn't trust untouched stock forks for anything over a mid-pack Int. pace.

Good luck with it, Zipster.

jk750 · 10-09-2006, 12:33 PM

Stock forks generally suck for the track. Most of the adjustments don't do anything outside a few clicks. They might give you 20 clicks and only 5 of them do anything.