BARF - Bay Area Riders Forum

Go Back   BARF - Bay Area Riders Forum > Sponsors > The Suspension Forum Presented by GP Suspension


Reply
 
Thread Tools Display Modes
Old 08-06-2017, 11:30 AM   #16
ontherearwheel
Veteran
 
Founding Member

Join Date: May 2002
Location: milpitas
Motorcycles: Tracer 900 GT, FZR 400 track bike, 04 R1 track bike
Name:
Quote:
Originally Posted by afm199 View Post
True, but in this case we're talking about spin and pump on corner exit, not bumps.
Knowing what is being discussed is critical in providing feedback. The stated issue did not occur on smooth corner exits, but on bumpy ones, even with little ripples.

Since it appears you missed this point, does the feedback you provided really apply when you did not consider the complete issue as stated?
__________________
A wise rider is a live rider
ontherearwheel is offline   Reply With Quote
Old 08-06-2017, 11:35 AM   #17
afm199
Veteran
 
afm199's Avatar
 
Mod Alumni
Founding Member
Top Percent Poster
Contributor +++++++++ ++++++++++++++3%

Join Date: Sep 2002
Location: Oaklamd
Motorcycles: Yamasuzhonaki 1450
Name: Beelzebub
Quote:
Originally Posted by ontherearwheel View Post
Knowing what is being discussed is critical in providing feedback. The stated issue did not occur on smooth corner exits, but on bumpy ones, even with little ripples.

Since it appears you missed this point, does the feedback you provided really apply when you did not consider the complete issue as stated?
I stand corrected. However I do doubt that the chain is an issue, particularly given the person who has the problem, who is pretty thorough on bike setup. In order for chain slack to be an issue, it requires compression to the point that the chain is taut and inhibits suspension travel. That's not happening on a 600 on minor ripples on the throttle. In my opinion.

I might go for reducing high speed compression damping.
__________________
That's not true! The lie is actually the truth! I know. Lots of people know this.

Last edited by afm199; 08-06-2017 at 12:01 PM..
afm199 is offline   Reply With Quote
Old 08-06-2017, 07:54 PM   #18
stangmx13
not Stan
 
stangmx13's Avatar
 
Contributor
BrotoGP

Join Date: Feb 2005
Location: San Diego CA
Motorcycles: 04' 600RR, 09' 600RR, 15' R6
Name: Robert
Chain slack is set at 40mm which is more than enough to prevent bind.

A good rear suspension will generally extend some on corner exit. This issue prob isn't happening well down in the stroke where the chain tightens up. So even though this is happening over bumps, it's unlikely that the chain could be too tight here even at the OEM chain slack.
__________________
BrotoGP Podcast and on Youtube
WERA #513 / AFM #513R / MotoAmerica #31
Follow me on IG @rwpierce13
Thanks to: RiderzLaw Vortex
stangmx13 is offline   Reply With Quote
Old 08-07-2017, 06:46 AM   #19
Reli
Veteran
 
Reli's Avatar
 
Contributor +++

Join Date: Mar 2010
Location: land of milfs and range rovers (danville)
Motorcycles: motorcycles
Name: reli
Yeah 40 is more than good. I still laugh at one owners manual I saw, think it was the gsxr I owned, that said 20-25mm. Dudes must have been on crack when they wrote that. Njoy your output bearing failure!

I'm not surprised you saw improvement from reducing the preload. Do you have sag measurements before and after?
Reli is offline   Reply With Quote
Old 08-07-2017, 11:16 AM   #20
stangmx13
not Stan
 
stangmx13's Avatar
 
Contributor
BrotoGP

Join Date: Feb 2005
Location: San Diego CA
Motorcycles: 04' 600RR, 09' 600RR, 15' R6
Name: Robert
Quote:
Originally Posted by Reli View Post
Yeah 40 is more than good. I still laugh at one owners manual I saw, think it was the gsxr I owned, that said 20-25mm. Dudes must have been on crack when they wrote that. Njoy your output bearing failure!

I'm not surprised you saw improvement from reducing the preload. Do you have sag measurements before and after?
why arent u surprised?

i measured when i got home / after making this thread. as expected, nothing is out of range.
Installed PreloadTotal Sag
13mm30mm
11mm33mm
9mm36mm

no suspension tuner would ever scoff at 30mm sag, but it felt like shit thats another reason y i never bother measuring sag. ppl get stuck on those numbers like they were handed down by moto gods. but obviously 30mm is not correct for me. in comparison, everyone is completely fine w/ 9mm installed preload.
__________________
BrotoGP Podcast and on Youtube
WERA #513 / AFM #513R / MotoAmerica #31
Follow me on IG @rwpierce13
Thanks to: RiderzLaw Vortex
stangmx13 is offline   Reply With Quote
Old 08-07-2017, 12:12 PM   #21
Reli
Veteran
 
Reli's Avatar
 
Contributor +++

Join Date: Mar 2010
Location: land of milfs and range rovers (danville)
Motorcycles: motorcycles
Name: 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.

Last edited by Reli; 08-07-2017 at 12:22 PM..
Reli is offline   Reply With Quote
Old 08-07-2017, 08:29 PM   #22
Mtfuzzy17
Newbie
 

Join Date: Mar 2017
Location: Newbury Park
Motorcycles: ZX10R
Name:
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.
__________________
www.gpsuspension.com

(805) 251-1400
2041 Cabot Place, Unit F Oxnard, CA 93030


Winning. Every. Day.
Mtfuzzy17 is offline   Reply With Quote
Old 08-07-2017, 10:05 PM   #23
stangmx13
not Stan
 
stangmx13's Avatar
 
Contributor
BrotoGP

Join Date: Feb 2005
Location: San Diego CA
Motorcycles: 04' 600RR, 09' 600RR, 15' R6
Name: Robert
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.
__________________
BrotoGP Podcast and on Youtube
WERA #513 / AFM #513R / MotoAmerica #31
Follow me on IG @rwpierce13
Thanks to: RiderzLaw Vortex
stangmx13 is offline   Reply With Quote
Old 08-08-2017, 05:13 AM   #24
afm199
Veteran
 
afm199's Avatar
 
Mod Alumni
Founding Member
Top Percent Poster
Contributor +++++++++ ++++++++++++++3%

Join Date: Sep 2002
Location: Oaklamd
Motorcycles: Yamasuzhonaki 1450
Name: Beelzebub
Quote:
Originally Posted by stangmx13 View Post
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.
__________________
That's not true! The lie is actually the truth! I know. Lots of people know this.
afm199 is offline   Reply With Quote
Old 08-08-2017, 06:15 AM   #25
Mtfuzzy17
Newbie
 

Join Date: Mar 2017
Location: Newbury Park
Motorcycles: ZX10R
Name:
Quote:
Originally Posted by stangmx13 View Post
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.
__________________
www.gpsuspension.com

(805) 251-1400
2041 Cabot Place, Unit F Oxnard, CA 93030


Winning. Every. Day.
Mtfuzzy17 is offline   Reply With Quote
Old 08-08-2017, 08:28 AM   #26
stangmx13
not Stan
 
stangmx13's Avatar
 
Contributor
BrotoGP

Join Date: Feb 2005
Location: San Diego CA
Motorcycles: 04' 600RR, 09' 600RR, 15' R6
Name: Robert
Quote:
Originally Posted by afm199 View Post
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.
__________________
BrotoGP Podcast and on Youtube
WERA #513 / AFM #513R / MotoAmerica #31
Follow me on IG @rwpierce13
Thanks to: RiderzLaw Vortex
stangmx13 is offline   Reply With Quote
Old 08-08-2017, 08:34 AM   #27
afm199
Veteran
 
afm199's Avatar
 
Mod Alumni
Founding Member
Top Percent Poster
Contributor +++++++++ ++++++++++++++3%

Join Date: Sep 2002
Location: Oaklamd
Motorcycles: Yamasuzhonaki 1450
Name: Beelzebub
Quote:
Originally Posted by stangmx13 View Post
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)
__________________
That's not true! The lie is actually the truth! I know. Lots of people know this.

Last edited by afm199; 08-08-2017 at 08:57 AM..
afm199 is offline   Reply With Quote
Old 08-08-2017, 09:23 AM   #28
stangmx13
not Stan
 
stangmx13's Avatar
 
Contributor
BrotoGP

Join Date: Feb 2005
Location: San Diego CA
Motorcycles: 04' 600RR, 09' 600RR, 15' R6
Name: Robert
Quote:
Originally Posted by Mtfuzzy17 View Post
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" . 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.
__________________
BrotoGP Podcast and on Youtube
WERA #513 / AFM #513R / MotoAmerica #31
Follow me on IG @rwpierce13
Thanks to: RiderzLaw Vortex
stangmx13 is offline   Reply With Quote
Old 08-08-2017, 09:28 AM   #29
stangmx13
not Stan
 
stangmx13's Avatar
 
Contributor
BrotoGP

Join Date: Feb 2005
Location: San Diego CA
Motorcycles: 04' 600RR, 09' 600RR, 15' R6
Name: Robert
Quote:
Originally Posted by afm199 View Post
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.
__________________
BrotoGP Podcast and on Youtube
WERA #513 / AFM #513R / MotoAmerica #31
Follow me on IG @rwpierce13
Thanks to: RiderzLaw Vortex

Last edited by stangmx13; 08-08-2017 at 09:29 AM..
stangmx13 is offline   Reply With Quote
Old 08-08-2017, 09:32 AM   #30
afm199
Veteran
 
afm199's Avatar
 
Mod Alumni
Founding Member
Top Percent Poster
Contributor +++++++++ ++++++++++++++3%

Join Date: Sep 2002
Location: Oaklamd
Motorcycles: Yamasuzhonaki 1450
Name: Beelzebub
Quote:
Originally Posted by stangmx13 View Post
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.
__________________
That's not true! The lie is actually the truth! I know. Lots of people know this.

Last edited by afm199; 08-08-2017 at 09:50 AM..
afm199 is offline   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -8. The time now is 09:19 PM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2019, vBulletin Solutions, Inc.