spin and pump on corner exit

[Reli]

That's rider sag right, not static sag?

I agree there's no magic number, but...........30 might be good for a smooth track, but consider that most people recommend more for the streets, probably because streets are bumpier than tracks. So if your track is particularly bumpy, I'm gonna speculate it makes sense to move towards a street setting.

Anecdote: I remember when I first started riding, the local "bros" would tell me to max out the rear preload to make it feel "sporty". And I did it, without even knowing what my sag was. Then I started noticing how my ass would catch air over bumps.

 

[Mtfuzzy17]

When is the last time your suspension was serviced?
Does your shock have Nitrogen in it?
A 9.0 shock spring is a little on the light side imo.

 

[stangmx13]

Has 6 weekends on it since service in March.

I'd expect that a 95 spring would make this issue worse, not better. Am I wrong? I moved away from the 95 and went faster right away. But I haven't tried it with this new valving.

 

[afm199]

Has 6 weekends on it since service in March.

I'd expect that a 95 spring would make this issue worse, not better. Am I wrong? I moved away from the 95 and went faster right away. But I haven't tried it with this new valving.

It will make it better or worse, which is why I suggested trying both options.

What tire? My GSXR1000 will spin and pump the SC2.5 (Phillip Island tire) but it isn't a problem with softer tires.

 

[Mtfuzzy17]

Has 6 weekends on it since service in March.

I'd expect that a 95 spring would make this issue worse, not better. Am I wrong? I moved away from the 95 and went faster right away. But I haven't tried it with this new valving.

It seems you are focusing too much on sag. Sag is an arbitrary number since it will change when you add or take away spring.
Where's your geometry? Shock length, fork springs, tires and/pressures. Swing arm length? Why did you change shock piston?
I've seen tons of racers go for the latest greatest MotoAmerica set up but in reality ( no offense ) most riders aren't fast enough for that "set up"....
Just because that set up worked for example JD or Gerloff doesn't mean it will work for you.
Call me at the shop, and I'll help you out.

 

[stangmx13]

It will make it better or worse, which is why I suggested trying both options.

What tire? My GSXR1000 will spin and pump the SC2.5 (Phillip Island tire) but it isn't a problem with softer tires.

someone has an educated idea as to which one will happen, better or worse. im ok w/ being the guinea pig, just blindly trying one, but itd be great to increase my chances of trying to "better" one.

Dunlops of course. optimal tire pressure helped with this, but it was never enough. the issue gets more pronounces as the tire drops off as expected.

 

[afm199]

someone has an educated idea as to which one will happen, better or worse. im ok w/ being the guinea pig, just blindly trying one, but itd be great to increase my chances of trying to "better" one.

Dunlops of course. optimal tire pressure helped with this, but it was never enough. the issue gets more pronounces as the tire drops off as expected.

Agreed. What compound Dunlop? IMGO going with a slightly lighter spring would help. (IMGO= In My Gratuitous Opinion)

 

[stangmx13]

It seems you are focusing too much on sag. Sag is an arbitrary number since it will change when you add or take away spring.
Where's your geometry? Shock length, fork springs, tires and/pressures. Swing arm length? Why did you change shock piston?
I've seen tons of racers go for the latest greatest MotoAmerica set up but in reality ( no offense ) most riders aren't fast enough for that "set up"....
Just because that set up worked for example JD or Gerloff doesn't mean it will work for you.
Call me at the shop, and I'll help you out.

"focusing on sag" :laughing. i think u missed some important details in my posts.

i changed the shock piston to help the shock feel settled. i was getting a lot of low speed movement everywhere that was annoying. more than a couple crew chiefs said it would help as thats apparently a common problem with the original KTech piston. it did.

no offense taken. u have no idea what kind of rider i am. but u made some poor assumptions. i paid a reputable crew chief for setup work - do u really think he'd give me Gerloff's setup without looking at my laptimes and watching my riding. i raced with him at 4 MotoAmerica rounds this year. the setup is good and well tailored to my speed and my riding style. the bike is already 90% perfect, i just wanna get it to 95% so its easier for me to improve my riding. my test&tune last time out was to experiment with some nagging issues, and without his help.

im here to discuss concepts, essentially the why and how something works or doesnt work, and to learn from it. im not here for a new setup or a new suspension tuner. id love to hear why u think too light of a spring can contribute to spin/pump on corner exit.

 

[stangmx13]

Agreed. What compound Dunlop? IMGO going with a slightly lighter spring would help. (IMGO= In My Gratuitous Opinion)

all of them. MA events were the GPA Pros and i raced the 2662 Soft whenever it was in the allocation and the weather agreed. for Miller, we had to use the 7455 Med. for club races, i use the KR451 Slick and always use the 2662 Soft. i can feel the difference in the tire, but have never felt the need to make large changes. i havent club raced since Dunlop released new compounds and the new 180/60, but i doubt itll change much.

ya im leaning that way as well, if im going to try something.

 

[afm199]

all of them. MA events were the GPA Pros and i raced the 2662 Soft whenever it was in the allocation and the weather agreed. for Miller, we had to use the 7455 Med. for club races, i use the KR451 Slick and always use the 2662 Soft. i can feel the difference in the tire, but have never felt the need to make large changes. i havent club raced since Dunlop released new compounds and the new 180/60, but i doubt itll change much.

ya im leaning that way as well, if im going to try something.

When I worked with Martin Scwarz, MFMC was crewing for him. I recall that Martin carried a spare shock and several springs and we'd swap out often ( twice a day) on some days. Of course Martin got yelled at a bit by Mike for wanting to change stuff so much. "GO RIDE!!"

Yeah, I know you are looking for more ways to spend money on racing.

 

[thedub]

id love to hear why u think too light of a spring can contribute to spin/pump on corner exit.

It sounds like if you call him he will explain it.

You posted in the GP Suspension forum. Now Mike from GP Suspension is offering to help. If you wanted a bunch of internet randoms pitching in their $.02 you could have just posted this in the Garage sub-forum.

 

[stangmx13]

It sounds like if you call him he will explain it.

You posted in the GP Suspension forum. Now Mike from GP Suspension is offering to help. If you wanted a bunch of internet randoms pitching in their $.02 you could have just posted this in the Garage sub-forum.

whats the point of a forum if every thread ends in "call me, ill help u out" :laughing

online discussion can help more than just one person too.

 

[Holeshot]

whats the point of a forum if every thread ends in "call me, ill help u out" :laughing

online discussion can help more than just one person too.

Robert, Fuzzy knows who you are because I told him who you are. He knows who your suspension guy is based on what you've said and I've told him. He really is trying to help you without starting a huge discussion online. A typical BARF discussion would cost GP Suspension about $250 in tech time...

 

[stangmx13]

Robert, Fuzzy knows who you are because I told him who you are. He knows who your suspension guy is based on what you've said and I've told him. He really is trying to help you without starting a huge discussion online. A typical BARF discussion would cost GP Suspension about $250 in tech time...

thats y we all BARF in our free time, not on the clock, right...

u know me, i try to contribute and be helpful on this forum. i volunteered some specific and a lot of general information to facilitate discussion. this subforum needs the help, after all. but it wasnt enough and im sad the thread is dead.

im not gonna hold it against a business if they dont want to give away their intellectual property or waste their time. its a fine line, being helpful vs giving shit away. navigating the line is tough. but i do know itd waste their time if i called :laughing