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Author Topic: tank slappers at 40mph  (Read 2039 times)

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#20

Offline HeavyRain

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Re: tank slappers at 40mph
Reply #20 on: 19 Jul 21, 07:52:31
Have you tried riding on the negative camber of the wrong side of the road? I wonder if you'd get a different result? Other than a head-on with on-coming traffic, obviously!

#21

Offline aljaxon

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Re: tank slappers at 40mph
Reply #21 on: 19 Jul 21, 08:36:43
*Originally Posted by HeavyRain [+]
Have you tried riding on the negative camber of the wrong side of the road? I wonder if you'd get a different result? Other than a head-on with on-coming traffic, obviously!

I havent but i will have a go. when i rode down my street on the video i am in the middle of the road at the top of the camber

a pal told me honda vfr's  all waggle when the tyres get down to 3/4 worn.
just googled this from a vfr forum back in 2005

headshake on decel has been an on/off issue with VFRs since the 4th gen came out. I'd try a different brand front tire. I had headshake on Dunlops, but not on Metzlers, Avons or Michelins.

and then i spotted this

Please note that most bikes will experience a normal deceleration wobble if you let go of the bars... most noticeable as speed drops in the 40 to 30 range... if you grip the bars back and it should go away...

Bike manufactures spend huge sums of money working directly with tire manufactures in designing special tires specifically for each model that quills this natural tendency...


very interesting. as i say the bike handles perfect for me all the time apart from this decelleration wobble. i might not rush to change the tyres and only do so when they are virtually worn out. like i normally do.
im a yorkshireman .....


Last Edit: 19 Jul 21, 08:43:12 by aljaxon
Z1000SX 2018   ZX9R 1998    RD350A 1974
PUCH M50 SPORTS  MOBYLETTE 50V 1974 
PALOMA D.A.S.L 1960

#22

Offline aljaxon

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Re: tank slappers at 40mph
Reply #22 on: 19 Jul 21, 08:38:30
forgot to mention due to my riding style my front tyres usually wear down to a v shape and the rears just go square like most riders

this is the link

just about everyone got this decell head shake

https://www.vfrdiscussion.com/index.php?/forums/topic/14706-front-end-shake-help/
Last Edit: 19 Jul 21, 08:41:16 by aljaxon
Z1000SX 2018   ZX9R 1998    RD350A 1974
PUCH M50 SPORTS  MOBYLETTE 50V 1974 
PALOMA D.A.S.L 1960

#23

Offline aljaxon

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Re: tank slappers at 40mph
Reply #23 on: 23 Jul 21, 11:48:45
*Originally Posted by KD [+]
Change the tyres, Thats a good start..  :028: Now-a-days you don't get the 2 rear to 1 front anymore.

Now .. Put a cable tie (Ty-wrap) around your front right fork stanchion and it push up to the fork seal. Next time you ride , see how far your front dives under braking. if your close to 1cm from the bottom, You will find you need more preload at the front as well as with rebound and compression adjustments ..

Same for the rear .. As the SX is a Sports/Tourer (and not a Sports bike) You should do a sag check with you on the bike and then with you and your misses on the bike and try to get to the max sag setting of 40mm. Anything above that and its sagging too much and you need a stiffer spring.

The standard spring on the SX is 95N. I replaced mine with a K-Tech 110N spring.

just did a sag check with the aid of my missus and a pal. with just me on my rear sag with max preload is 46mm. cant get it any less.
with me and my missus on its 75mm!!!!
im trying to imagine what it would be with my two panniers and topbox crammed tight with clothing we didnt need. no wonder my side stand wouldnt go down.

yet the bike didnt feel as if it was bottoming out and handled great.
in my luddite opinion.

so KD if ive got 46mm with preload fully wound clockwise and 73 mm 2 up is a 110N spring such as yours gonna by stiff enough?

i measured  vertically ie from allen bolt at swing arm rear to indicator/numberplate bracket thing
Z1000SX 2018   ZX9R 1998    RD350A 1974
PUCH M50 SPORTS  MOBYLETTE 50V 1974 
PALOMA D.A.S.L 1960

#24

Offline aljaxon

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Re: tank slappers at 40mph
Reply #24 on: 23 Jul 21, 03:13:21
Z1000SX 2018   ZX9R 1998    RD350A 1974
PUCH M50 SPORTS  MOBYLETTE 50V 1974 
PALOMA D.A.S.L 1960

#25

Offline KD

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Re: tank slappers at 40mph
Reply #25 on: 23 Jul 21, 04:55:18
Hi Aljaxon.

All I know is that the 110N spring works for me and I have 9 clicks spare with 45mm sag. So i'm presuming it can only going to help your situation.
Regards David.

2018 Kawasaki Z1000SX WJF.
2018 Triumph Tiger 1200 XRT.

#26

Offline aljaxon

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Re: tank slappers at 40mph
Reply #26 on: 23 Jul 21, 04:59:56
ok cheers kd

now to look for some yellow paint to make the ktech spring look like its ohlins
Z1000SX 2018   ZX9R 1998    RD350A 1974
PUCH M50 SPORTS  MOBYLETTE 50V 1974 
PALOMA D.A.S.L 1960

 



expletive