Tyre wave pattern

[Gixxer 4 ever]

Oh yea the photographers name is Euan Cameron and his email is euan@cameronphoto.co.nz Good luck tracking down a photo or 2.

Thank you for the name and Email. You the man... ...Do you know Euan? I will send him mail now.

[R1madness]

Know him thru racing bikes. He is a decent guy but a little busy. If ya are nice to him he will look a bit harder. His pics are top quality and worth the price he charges.

[Gixxer 4 ever]

Know him thru racing bikes. He is a decent guy but a little busy. If ya are nice to him he will look a bit harder. His pics are top quality and worth the price he charges.

Cool. I will hunt for his race number over the weekend, for that year, and see what I can find. I have sent Euan mail.

[slob]

I've got a GSX-R750T ('96) with a 180 section Metzler Sportec M1 on the rear. Last time I was at Pukekohe on a trackday, I noticed the same pattern forming on my tyre. I'd say it was due to a combination of having the wrong suspension setup (damping was low - on road settings) and tyre pressure (released too much air in my haste to get on the track).

Basically, if your tyres are wallowing around while you're leaned over, you will get that pattern.

[TwoSeven]

So why wouldnt it be an incorrect tire pressure then ?

[slob]

So why wouldnt it be an incorrect tire pressure then ?

If the suspension isn't damping the spring action, then I imagine the tyre will be bouncing around excessively, thus forming the wavy wear pattern I imagine..

[DEATH_INC.]

A couple of things....
All the srad 750's run a 6" rear ,hence the 190.
Don't run the rebound too stiff,it'll pack down and make it real harsh feeling.....run it as light as you feel comfortable with.....alternately don't make the compression too light,it needs to be as firm as poss while still feeling compliant....

[Gixxer 4 ever]

Holy shit...............What a difference......I had to drop the rebound back a bit but what a ride.......
One more question.......I know I have asked enough but this advice has made this bike ride so much better, and I loved it before. Anyway I recon the front is less stable. That is it appears to lift a lot more under power. A bit off putting to start with when coming out of corners or opening the throttle to pass cars. She always unloaded the front but it lifted it twice in the first 3 ks as we headed up the Wairoa road. Why?
F#uk I love this bike
Will report after the weekend when I have had a chance to play some more.
Thanks people

[Gixxer 4 ever]

TWOSEVEN - What doesn't sound right? 5.5inch rims are designed for 180 tyres except for the single type of one that was fitted to the bike from new by the manufactures. .

I had a look at a mates Black bird today and what you said is correct. It has a 5.5" rim.
Amazing what you learn when people share information. Thanks R1

[Brian d marge]

Can I ask what wieght you are and if the bike has a standard shock ( as in unmodified)

Stephen

[R1madness]

Holy shit...............What a difference......I had to drop the rebound back a bit but what a ride.......
One more question.......I know I have asked enough but this advice has made this bike ride so much better, and I loved it before. Anyway I recon the front is less stable. That is it appears to lift a lot more under power. A bit off putting to start with when coming out of corners or opening the throttle to pass cars. She always unloaded the front but it lifted it twice in the first 3 ks as we headed up the Wairoa road. Why?
F#uk I love this bike
Will report after the weekend when I have had a chance to play some more.
Thanks people

Take a couple o clicks o rebound off the front (to allow the forks to extend a little quicker under acceleration) and take off 4 clicks o compression from the rear (to allow it to squat just a little). Just fiddle fiddle. Adjust one setting at a time and see the effect. SO many people are too nervous to play with their suspension settings and dont realise that they probibly have it all wrong anyway. Just keep playing mate.

[DEATH_INC.]

I'd suspect it's because the rear no longer squats that the c.o.g. is higher and that's why the wheelies.....like r1 sez, just experiment a little at a time,you can always go back. keep a written record of what you've done and what it does.

[Gixxer 4 ever]

Can I ask what wieght you are and if the bike has a standard shock ( as in unmodified)

Stephen

Hi Stephen. It is standard. I will check for the 5mm lift when I have this tyre off next. A mate added an 8mm lift to his Black Bird and it has made a massive difference to the turn in. 8 mm at the shock = 20mm at the back of the swing arm. So he told me. I have not done the maths but the tyre is now on the ground when he has the centre stand down.
I am 110 kg's and 6 1. I know I am a bit big for the 750 but I saw this bike on TradeMe and just wanted it. So I got it. I like the fact it had some history and Mary loved the colour. I have no problems keeping up with the big bikes and we tour from time to time on it. Pillion seat is very comfy for a sports bike.We have done a few trips to Auckland and Welly town and many places in between.

[Brian d marge]

I know that feeling about just wanting bikes ...Every bike I see I want !
Anyway suspension set up , I fel that the original problem is tyre squirm , wether caused by, supension or Tyre pressure I dont know.

What I would do is set the bike up for your wieght.
1 check the sags ( if you are not sure how to do this correctly I can send you document which explain in easy language ...as I am a bit slow so needed it in simple terms )
The sags will tell you if springs are to soft or hard ( I suspect to soft )

At this point if you dont correct the spring rate all other changes just mask the inherent problem,

Set clickers to the factory settings , or the middle

NOW go riding and as others have said change only ONE thing at a time and note the effect
( if you need a list of causes and effects again PM me )

make the changes untill the bike feel nice and holds the line through a bumpy sweeper

The most likely reason why its tending to wheely is you have jacked up the preload so as the bike accelarates and the wieght is transferred to the rear...... the shock is trying to extend but is being squashed by the wieght transfer by adding more preload you have given the shock more advantage ie empowered the shock to extend which will tend to lift the bike ie tend to wheely

That was a crap explaination try this... wieght transfer -( energy in spring + added preload given by preload ) equals wheely rate !

If that makes sence then cool , if not Pm me and I will scan a diagram with the maths which would probably make more sence!!

Finally when all that is done Then you go and start with adding /subtracting tyre pressures . clicker adjustments ..to see if the tyre wear pattern grows bigger or smaller

and when you get to rossis level and can constantly hold the same line through a turn all the above rubbish become Kawooshial ( sorry I am watching monty pythons life of brian on web tv while typing this and they are up to the Bigus Dickus scene ,,,thats a classic scene)

Anyways good luck

Stephen

[Gixxer 4 ever]

I know that feeling about just wanting bikes ...Every bike I see I want !
Anyways good luck

Stephen

Everything you say sounds good. I am working on the one click thing and I think I have it close to as good as I can get it. It appears the wave pattern has gone. I need a longer hard ride to see but it all feels good.
I like the lift in the front. I can dial it out, as you say, but I am enjoying it at the moment. Added value on a harder ride. I am just a boy at hart. When I say it lifts the front we are not doing the big wheelie thing just up off a little and the throttle controls it nicely.Thanks for your time and info.
Roll on tomorrow. Hope I have enough tyre to get to Paeroa and back