Rear Chatter - Suspension Issue or Riding Style

For general Technical and Performance Discussions
Post Reply
User avatar
bjn_42
KSRC Member
KSRC Member
Posts: 174
Joined: Tue Dec 27, 2011 7:19 pm
Bike: ZX6R
State: Queensland
Location: Qld

Rear Chatter - Suspension Issue or Riding Style

Post by bjn_42 »

Hi Guys,

I had my suspension adjusted on my track bike recently and it made a huge improvement to the bikes stability. However there still appears to be a small amount of chatter coming from the rear. It only occurs when braking heavily (i.e. turn 3 at Queensland Raceway). I did notice that the chatter went away when i did not use the rear brake.

So is this issue suspension or riding style related?
Your ambition outweighed your talent
User avatar
Wattie
VIP MEMBER
VIP MEMBER
Posts: 10041
Joined: Mon Oct 31, 2005 12:23 pm
Bike: ZX10R
State: New South Wales
Location: Bligh Park

Re: Rear Chatter - Suspension Issue or Riding Style

Post by Wattie »

Locking the rear. It will be less if you feather the clutch a bit.
Wattie #55
ZX10R "The Crim"
ZX10R "Gumby"
Proudly Supported by Allfixed Automotive 9634 1455
sam & srt, survived
RGM, left a message
User avatar
paulsj
KSRC Member
KSRC Member
Posts: 224
Joined: Thu Jun 03, 2004 3:37 pm
Bike: ZX9R
State: Victoria
Location: melbourne

Re: Rear Chatter - Suspension Issue or Riding Style

Post by paulsj »

Style. Slipping clutch a little or less engine brakes could work too, by braking then shifting and tip in. Have been working on both of these on my ZX9R to stop the same thing.
User avatar
MadKaw
Administrator
Administrator
Posts: 9671
Joined: Tue Apr 20, 2004 4:33 pm
Bike: ZX10R
State: New South Wales
Location: Windsor or the Creek..
Contact:

Re: Rear Chatter - Suspension Issue or Riding Style

Post by MadKaw »

maybe increase the idle rpm too...
Dave
2010 Z1000
ex bikes
05 ZX-10R Race Bike - No.77
95 ZXR750R M Race Bike - No. 75
98 ZX9R Race Bike - No. 000
zx6r, zx7r, GPX750, GPX500, lots of KX's.
Image
I ride way too fast to worry about cholesterol
User avatar
Jonnymac
KSRC Contributor
KSRC Contributor
Posts: 1165
Joined: Thu Jun 16, 2011 1:33 pm
Bike: ZX6R
State: Victoria

Re: Rear Chatter - Suspension Issue or Riding Style

Post by Jonnymac »

MadKaw wrote:maybe increase the idle rpm too...
This ^
I wrote it earlier but for some reason it didn't post......
User avatar
bjn_42
KSRC Member
KSRC Member
Posts: 174
Joined: Tue Dec 27, 2011 7:19 pm
Bike: ZX6R
State: Queensland
Location: Qld

Re: Rear Chatter - Suspension Issue or Riding Style

Post by bjn_42 »

I tried feathering the clutch and that worked really well but it doesnt seem to come naturally to me. I might try playing with the rebound a bit before I try anything else as it doesnt require me to change my riding style.
Your ambition outweighed your talent
User avatar
Wattie
VIP MEMBER
VIP MEMBER
Posts: 10041
Joined: Mon Oct 31, 2005 12:23 pm
Bike: ZX10R
State: New South Wales
Location: Bligh Park

Re: Rear Chatter - Suspension Issue or Riding Style

Post by Wattie »

Practice practice practice.
back before slipper clutches feathering was the only way
Wattie #55
ZX10R "The Crim"
ZX10R "Gumby"
Proudly Supported by Allfixed Automotive 9634 1455
sam & srt, survived
RGM, left a message
User avatar
bjn_42
KSRC Member
KSRC Member
Posts: 174
Joined: Tue Dec 27, 2011 7:19 pm
Bike: ZX6R
State: Queensland
Location: Qld

Re: Rear Chatter - Suspension Issue or Riding Style

Post by bjn_42 »

Just did some research and found out the CBR doesnt have a slipper clutch however the ZX6R does. This may explain why it has never been a problem for me in the past.
Your ambition outweighed your talent
User avatar
Wattie
VIP MEMBER
VIP MEMBER
Posts: 10041
Joined: Mon Oct 31, 2005 12:23 pm
Bike: ZX10R
State: New South Wales
Location: Bligh Park

Re: Rear Chatter - Suspension Issue or Riding Style

Post by Wattie »

bjn_42 wrote:Just did some research and found out the CBR doesnt have a slipper clutch however the ZX6R does. This may explain why it has never been a problem for me in the past.
Doh!
Wattie #55
ZX10R "The Crim"
ZX10R "Gumby"
Proudly Supported by Allfixed Automotive 9634 1455
sam & srt, survived
RGM, left a message
User avatar
paulsj
KSRC Member
KSRC Member
Posts: 224
Joined: Thu Jun 03, 2004 3:37 pm
Bike: ZX9R
State: Victoria
Location: melbourne

Re: Rear Chatter - Suspension Issue or Riding Style

Post by paulsj »

How high do guys turn the idle to reduce locking the rear under brakes I had mine at about 2700rpm which helped but made me cringe everytime clicking from neutral to first. Seemed to help but just rebuilt my calipers so hoping the stoppers are going to be working even better this time
User avatar
MadKaw
Administrator
Administrator
Posts: 9671
Joined: Tue Apr 20, 2004 4:33 pm
Bike: ZX10R
State: New South Wales
Location: Windsor or the Creek..
Contact:

Re: Rear Chatter - Suspension Issue or Riding Style

Post by MadKaw »

I had the idle on my old zx9 race bike at about 2000 to 2200 rpm, It was fine and you could back it in a little on down shift. I also had the zx10r at about 2000 as the higher idle also makes getting on the gas a little smoother mid corner.. Not sure I'd go as high as 2700 though, but if it works, do it...... Maybe start in 2nd.. ;)
Dave
2010 Z1000
ex bikes
05 ZX-10R Race Bike - No.77
95 ZXR750R M Race Bike - No. 75
98 ZX9R Race Bike - No. 000
zx6r, zx7r, GPX750, GPX500, lots of KX's.
Image
I ride way too fast to worry about cholesterol
s man
KSRC Regular
KSRC Regular
Posts: 809
Joined: Sun Mar 14, 2010 7:58 am
Bike: Z1000
State: New South Wales
Location: Lake Mac NSW

Re: Rear Chatter - Suspension Issue or Riding Style

Post by s man »

My GSXR did the same thing when we went to superbike spec engine
Increase idle to 3000/3500 rpm,
Shaffer the rear pads, so you dont get as much bite,
Dont down shift to high in the rev range.
Fit slipper clutch.
Feather the clutch.
Dont use the rear brake until you get more experience.
ʎɐqǝ uo pɹɐoqʎǝʞ ɐ ʎnq ı ǝɯıʇ ʇsɐן ǝɥʇ sı sıɥʇ
User avatar
bjn_42
KSRC Member
KSRC Member
Posts: 174
Joined: Tue Dec 27, 2011 7:19 pm
Bike: ZX6R
State: Queensland
Location: Qld

Re: Rear Chatter - Suspension Issue or Riding Style

Post by bjn_42 »

Just as a conformation it was definitely a riding style issue. I tried changing down gears later in braking and that smoothed everything out. Took a few sessions to get used to but i had down pat by lunch time. Thanks for the information guys!
Your ambition outweighed your talent
Post Reply