Tires slipping on wheel

I have a 2019 Panigale V4 that I use for the track only.
I usually run rear 200/60 SC1 or SC2, set to 25-27 PSI out of the warmers, and front 120/70 SC2, set to 34 PSI on OEM 2018 V4S forged aluminum Marchesini wheels.
Thus far, my Ducati dealer has been mounting and balancing all my tires and I have no complaints with them.

Recently, I started marking the tires to monitor any slippage on the wheels and was surprised to see that my new SC1 rear tire had slipped half way around the wheel after 1 day at Willow Springs.
The front slips also, but only a few degrees. I may also be experiencing some bumpy vibrations now on these used tires, but that could also be due to some new screwy suspension settings I was trying.

My question: Are there generally accepted do's and don'ts for tire mounting on powerful track-bikes like these? Lubed mounting, dry mounting, buying wheels with anti-slip surface, not worrying about it...?
Thanks!

The only thing that was really effective for me was spraying hairspray on the bead of the rim. Ultimately, I sent them off to have anti-slip painted on which is the best solution.

a bit of slip is normal. half a rotation after a whole day of riding, youre not going to notice that in your lap times. With the powerful bikes and excellent tire tech something has to give

Are you loosing any air pressure measuring cold before, cold after?

Keith197 said:

The only thing that was really effective for me was spraying hairspray on the bead of the rim. Ultimately, I sent them off to have anti-slip painted on which is the best solution.

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Thanks for this info! Do you recall where you sent your wheels or the details of the anti-slip paint? Also, did you ever feel any imbalance issues? I'm not convinced I'm feeling anything adverse related to wheel-slip but I have a fresh set of balanced tires and will pay better attention and try to better correlate slip with any odd feel or vibrations. Thanks again!

Vbreeze said:

Are you loosing any air pressure measuring cold before, cold after?

Click to expand...

I haven't measured any loss of pressure.

Fry said:

I haven't measured any loss of pressure.

Click to expand...

Just out of curiosity how do you know the tyre only moved half a turn? Was it moving small amounts during the day and finished at halfway. The reason i ask is most tyres move on stock rims on track but usually small amounts but if they slip a lot more they usually slip a lot ans actually spin

the tire has a red weight dot.

i moved both front and rear a few degrees on my V2 and never run below 30 psi. i don't use the brakes that much but obviously hard enough

Bruce Wayne said:

Just out of curiosity how do you know the tyre only moved half a turn? Was it moving small amounts during the day and finished at halfway. The reason i ask is most tyres move on stock rims on track but usually small amounts but if they slip a lot more they usually slip a lot ans actually spin

Click to expand...

Hi, thanks for the question. I marked the rim and new tire with a paint pen. For some reason, I don't remember checking for movement session to session, but after I was done for the day (5 sessions), I saw that the marks had moved about 180 degrees apart. I reasoned that it was unlikely they moved a full 1.5 revolutions, so probably about 30-40 degrees per session.
It may be hard to see in this picture, but the white marks were lined up at the start of the day on the new tire. This is an SC1 from one day at Big Willow.



I don't really care that the tire slips, so long as it doesn't create an imbalance that I can feel. I've only just started marking my tires (out of curiosity), so I reason that I must have been experiencing similar slippage (and imbalance) for ~20 prior track days without knowing it or feeling anything. Once even, the wheel weights on my front flew off, despite being taped down, and I didn't notice any strange feel or vibration. I'm starting to conclude that yeah, tires will slip a bit on these powerful bikes, and yeah, it imbalances the wheels, but the effects are not noticeable while riding. I found this video from Dave Moss Tuning that seems to indicate the same:



I plan to pay more attention and note any effcts of tire slip/imbalance separately from suspension/setup changes. Thanks!

Keith197 said:

The only thing that was really effective for me was spraying hairspray on the bead of the rim. Ultimately, I sent them off to have anti-slip painted on which is the best solution.

Click to expand...

I don't know if that matters, but Bio Hairspray contains no silicone but shellac. maybe its worth a try.

Fry said:

Thanks for this info! Do you recall where you sent your wheels or the details of the anti-slip paint? Also, did you ever feel any imbalance issues? I'm not convinced I'm feeling anything adverse related to wheel-slip but I have a fresh set of balanced tires and will pay better attention and try to better correlate slip with any odd feel or vibrations. Thanks again!

Click to expand...

I sent mine to superbike unlimited but I know Brocks also does it. I never noticed any imbalance.

Fry said:

Hi, thanks for the question. I marked the rim and new tire with a paint pen. For some reason, I don't remember checking for movement session to session, but after I was done for the day (5 sessions), I saw that the marks had moved about 180 degrees apart. I reasoned that it was unlikely they moved a full 1.5 revolutions, so probably about 30-40 degrees per session.
It may be hard to see in this picture, but the white marks were lined up at the start of the day on the new tire. This is an SC1 from one day at Big Willow.

View attachment 35049

I don't really care that the tire slips, so long as it doesn't create an imbalance that I can feel. I've only just started marking my tires (out of curiosity), so I reason that I must have been experiencing similar slippage (and imbalance) for ~20 prior track days without knowing it or feeling anything. Once even, the wheel weights on my front flew off, despite being taped down, and I didn't notice any strange feel or vibration. I'm starting to conclude that yeah, tires will slip a bit on these powerful bikes, and yeah, it imbalances the wheels, but the effects are not noticeable while riding. I found this video from Dave Moss Tuning that seems to indicate the same:



I plan to pay more attention and note any effcts of tire slip/imbalance separately from suspension/setup changes. Thanks!

Click to expand...

Ok makes sense, i wouldnt worry about imbalance as even a perfectly balanced rear tyre will be out of balance after one session and you really wont notice it.

Fry said:

I have a 2019 Panigale V4 that I use for the track only.
I usually run rear 200/60 SC1 or SC2, set to 25-27 PSI out of the warmers, and front 120/70 SC2, set to 34 PSI on OEM 2018 V4S forged aluminum Marchesini wheels.
Thus far, my Ducati dealer has been mounting and balancing all my tires and I have no complaints with them.

Recently, I started marking the tires to monitor any slippage on the wheels and was surprised to see that my new SC1 rear tire had slipped half way around the wheel after 1 day at Willow Springs.
The front slips also, but only a few degrees. I may also be experiencing some bumpy vibrations now on these used tires, but that could also be due to some new screwy suspension settings I was trying.

My question: Are there generally accepted do's and don'ts for tire mounting on powerful track-bikes like these? Lubed mounting, dry mounting, buying wheels with anti-slip surface, not worrying about it...?
Thanks!

Click to expand...

I mount and balance my tires at home. I noticed a 90 degree tire slippage after a day at VIR this past August. I blamed it on the soap I was using. I plan to use hair spray next time I change tires. I don't notice anything during the day but I'm not very fast anymore. I doubt that I would notice any vibrations at the rear. I will start looking at the front tire for slippage going forward. I've thrown a wheel weight on the front before (it was taped) I got a very noticeable front tire vibration with speeds over 160MPH on my Tuono. I have a 2018 V4S and have had to make a lot of suspension and ride height changes to finally get the front tire feel I need to feel comfortable. I would hate to have unwanted front tire vibrations.

Interesting enough I jsut got some new wheels last night and immediately though of this thread. These are OZs that came off of a Chaz Davies bike. Note the inside where the tire beads up is finished with a gritty texture to help prevent tire slippage.

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KarlKani said:

Interesting enough I jsut got some new wheels last night and immediately though of this thread. These are OZs that came off of a Chaz Davies bike. Note the inside where the tire beads up is finished with a gritty texture to help prevent tire slippage.

Click to expand...

Thanks! Do you suppose those wheels came like that from the OZ factory, or was the finish was applied as a mod by his racing team? Did they add material as in patin, ro take some away as in grinding? I have a new tire guy who's an expert machinist and he suggested he could pretty easily grind off the smooth-finished surface paint to create more friction. I also found this as an option: UHS Anti-Slip Coating Installed on BST Wheel

By the way, your Winter Mode build thread is some seriously inspiring bike porn. I love it!

They came from OZ like this, I am not too sure what process they used.


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I change my own tires and actually I've often done this without any balancing (front and rear). I only use my V4 for trackdays and I've never feld any vibration when doing this, even on very fast (300+kmh) tracks like Spa, Catalunya and Mugello.
So I'm not convienced that balancing is that important on bikes. But that's just my personal opinion.

on the front always.
But the marcesinis are very good (if new/ok), last time with sc3 i "needed" 5gr.

I'm not sure if this is only a balancing problem, or has a balancing aspect.
not sure if its really better with a rough surface or maybe gluing with hairspray makes less work on the long run.
i found a lot of rubber on the rough inside of a pair of sumo wheels few days ago.

btw.
I've made this sumo tubeless.
today i found the rear wheel flat, f***.
flat, again! incontinent at the same spot!
?strange.
reason was, I think, the little barcode sticker at the tire. it is very hard compared to the rubber and can't go smooth into the file like rim surface.
sandpaper did the job, i hope.