revtothelimit - motorbike forum

Any suspension guru’s have a definite answer as to what’s going on here? (Assuming the photos come out)
Second time out on the 5jj R1 and although we’re hardly setting the world on fire pace wise the rear Metzler TD slick has taken a bit of a beating. I know it’s not cold tear and pretty sure it’s not hot tear, thinking it’s more likely rebound related due to the jagged pattern on the inside. If that’s the case, too much or too little rebound, that’s the question?
Anyone come across similar wear patterns and managed to tune it out?
Thanks in advance, Paul.

You see a lot of slicks like that in novice and inters where the temp can’t be kept high enough for them. Whilst not cold it can be called cold tear. What track and what pace ?

Silverstone on Sunday, I know it’s not cold tear, it was a warm day, they were holding the correct pressure after each session and then straight back on the tyre warmers, and as mentioned, they are the TD slicks, supposedly designed to run without tyre warmers.
You don’t think the jagged wear line is indicative of a suspension issue then?

Bit late now, but usually there are tyre and suspension bods at trackdays they'd probably have been able to give a good idea. Personally I have no clue, sorry!

Do you like how it handles, if yes, you haven't got a problem, if no you have got a problem, staring at the tyres is looking for problems that aren't there, stop thinking about it, get out there and ride it.

singlesman wrote: Tue Jun 08, 2021 9:49 pm Silverstone on Sunday, I know it’s not cold tear, it was a warm day, they were holding the correct pressure after each session and then straight back on the tyre warmers, and as mentioned, they are the TD slicks, supposedly designed to run without tyre warmers.
You don’t think the jagged wear line is indicative of a suspension issue then?

Cold tear is the tyre not working at its optimum not necessarily cold. Keeping a slick at its temperature isn’t really doable at a novice pace. Another cause is again by lack of pace and waiting till it’s more upright before getting on the gas which can look like your tyre.

Which group are you in as novice or inters you’d be better off with a sports tyre and no need for warmers tbh.

Thanks for the replies but not really what I was hoping for!
The bike handles pretty well, the k-tech forks need a bit more fine tuning but the rear feels pretty good, the issue being I can’t afford to be putting a new tyre on for every track day.
I know we don’t know each other Couchy but I raced for many years pre- tyre warmers so am quite familiar with cold tear.
Would also argue that cold tear is more about the tyre surface overheating while the carcass/wheel rim are too cold.
This pattern is not deep enough for that, more akin to hot tear with the rubber rolling off the surface, just the unusual jagged pattern I’m trying to figure out and the noticeable concave wear issue.
And again, these are metzler track day slicks, effectively a hard sports compound tyre in slick format of designed for slow old ‘has beens’ like myself.
Supermofo, that would have been the smart thing to do, we’re out at Donington inJuly so I’ll take it along and get some feedback from the tyre guys there.
Thanks.

Its coz you're a big girls blouse and riding too slowly.




Well that's what they told me

Your probably right, Couchy seems fairly convinced that’s where the problem lies!

My 2ps worth
Wait for it —

Too much tyre grip when your rolling throttle on

Several different ways to fix / correct it but proper suspension guy is route to speak to or Payton get done overall cheaper and better as you can get in right muddle as your dialling a proportion of grip out which is harder to get right than adjusting yourself to gain grip

Just a quick update and a bit of ‘humble pie’ eating re -Couchy’s above posts.
It would appear my beloved, £60 racetec tyre pressure gauge, which admittedly I’ve owned for ever, is reading 5psi low!!!
The funny thing is, I’ve long known it read differently from other (cheap) gauges I’ve got, but always assumed they must be wrong, well, because they’re cheap.
So, in effect the tyre wear probably is cold tear, caused by the small, overheated contact patch, ( due to over inflation) differing in temperature to the rest of the tyre.
I didn’t recognise it as such probably because the tyre isn’t a proper race slick and hasn’t torn up like one.
Anyway, having said all that, and despite the tyres having at least 5psi too much in them at both ends, they seemed to perform really well at my mediocre pace, not a single moment despite my ‘ ring rusty’ throttle control and cack handed grabbing of brakes , missing braking markers etc.
Gratuitous picture of me negotiating inters traffic!

Google hot tear. That's under inflation.

Singlesman are you the one at front, just off vertical?

No, I’m on the old R1 in the middle, desperately trying to keep up with an old racer mate, who’s a ex-California super bike school and now a Silverstone instructor, who’s rapidly disappearing up the road on Pirelli Diablo Rosso 111’s

Yorick, the gauge was reading low by 5psi, so 25 hot in the rear would have been 30psi.

singlesman wrote: Fri Jun 11, 2021 10:00 pm No, I’m on the old R1 in the middle, desperately trying to keep up with an old racer mate, who’s a ex-California super bike school and now a Silverstone instructor, who’s rapidly disappearing up the road on Pirelli Diablo Rosso 111’s

I was joking, the guy at the front should be in Novice with slow plebs like me.

Le_Fromage_Grande wrote: Fri Jun 11, 2021 10:20 pm

singlesman wrote: Fri Jun 11, 2021 10:00 pm No, I’m on the old R1 in the middle, desperately trying to keep up with an old racer mate, who’s a ex-California super bike school and now a Silverstone instructor, who’s rapidly disappearing up the road on Pirelli Diablo Rosso 111’s

I was joking, the guy at the front should be in Novice with slow plebs like me.

You should be on the girls trackdays

Yorick wrote: Fri Jun 11, 2021 10:29 pm

Le_Fromage_Grande wrote: Fri Jun 11, 2021 10:20 pm

singlesman wrote: Fri Jun 11, 2021 10:00 pm No, I’m on the old R1 in the middle, desperately trying to keep up with an old racer mate, who’s a ex-California super bike school and now a Silverstone instructor, who’s rapidly disappearing up the road on Pirelli Diablo Rosso 111’s

I was joking, the guy at the front should be in Novice with slow plebs like me.

You should be on the girls trackdays

Most of them are faster than me, it's guys on Fireblades and similar bikes I'm passing.