Scrubbing in tyres

[dern]

In my understanding scrubbing a tyre is about getting a tyre hot so that the tyre release agent is in effect sweated out... is that right? If so how can I achieve that this time of year?

Had to put a new 014 on the back of the blade and it's pretty slippery although not as bad as driving it in icy conditions with only 1 psi in it due to a puncture.

Cheers,

Mark

[s2ooz]

blast it down a motorway for 10 minutes.

[Vitesse39]

I believe it needs to be scrubbed/used across the whole surface so an upright blast will only do part of it. Think it will just take longer to scrub the surface on the shoulders as you can't go so much at this time of year.

[Mad Dave]

Vitesse39 said:

I believe it needs to be scrubbed/used across the whole surface so an upright blast will only do part of it.

I thought this, but tyre fitter told me that it's more to do with heat cycles.

[dern]

s2ooz said:

blast it down a motorway for 10 minutes.

Honestly? I don't want to try this and find I've got no grip as I negotiate a roundabout filled with myopic car drivers.

Cheers,

Mark

[Davel]

Winding 'A' roads and 'B' roads for about 40 miles?

[s2ooz]

Vitesse39 said:

I believe it needs to be scrubbed/used across the whole surface so an upright blast will only do part of it. Think it will just take longer to scrub the surface on the shoulders as you can't go so much at this time of year.

You'd be wrong.

Its purely a heat issue. time x temperature.
Scrubbing is a bad word to describe whats going on.

If sides needed scrubbing you would fall off on every first corner after fitting.

blast down the motorway, then stop and look at the tyre. you will note a "scrubbed" centre line where its been on the tarmac, and it maybe a lighter grey/black than the rest of the tyre and matt in appearance.

However, further across there should appear a sort of greasy blue line and the rest of the tyre will be shiney.
thats the release agent burning off. blast again, and the line will fade or move outward.

The warmer the tyre, the less distance you need to cover.

So in effect, 300 miles that has been done by going down the corner shop in 1 mile stints won't be safe for knee down next outing.
BUT: 2 stinking laps at silverstone will have it 'scrubbed' in ready - just 7 miles.
The heat a tyre gets to on a track is quiet suprising. It should feel like chewing gum after a session.

Hence, you are going to struggle to get the outsides warm in todays conditions, but even some heat will reduce the ratio of agent to rubber, making corners safer with each ride.

[dern]

s2ooz said:

Its purely a heat issue. time x temperature. Scrubbing is a bad word to describe whats going on. If sides needed scrubbing you would fall off on every first corner after fitting. blast down the motorway, then stop and look at the tyre. you will note a "scrubbed" centre line where its been on the tarmac, and it maybe a lighter grey/black than the rest of the tyre and matt in appearance. However, further across there should appear a sort of greasy blue line and the rest of the tyre will be shiney. thats the release agent burning off. blast again, and the line will fade or move outward. The warmer the tyre, the less distance you need to cover. So in effect, 300 miles that has been done by going down the corner shop in 1 mile stints won't be safe for knee down next outing. BUT: 2 stinking laps at silverstone will have it 'scrubbed' in ready - just 7 miles. The heat a tyre gets to on a track is quiet suprising. It should feel like chewing gum after a session. Hence, you are going to struggle to get the outsides warm in todays conditions, but even some heat will reduce the ratio of agent to rubber, making corners safer with each ride.

Good explanation - thanks

The guy fitting the tyre had a hell of a job getting the tyre on the rim. His workshop had got down to -4 or something like that overnight and the tyre just did not want to flex at all when I arrived late for work at 9.30.

[veetwin]

Scrubbed my last rear Diablo Corsa in on Donington, as S2ooz says, fit for full-on attack after 3 laps. Felt great all day long and was told of darkies being laid leaving Coppice in the afternoon. Air temp was 30°C though which probably helped a great deal.

Im sure a good burn out on some of the slippery roads may get the required heat into your fresh rubber.

[rumpelstiltskin]

I just about lost my Busa with a new tyre on it,scared the beejeesus out of me,since then i stick bike with new tyre on rear paddock stand,stick bike in first,let the clutch out slowly,jump of said motorcycle,just let the back wheel spin and hold a piece of sandpaper against the surface of the tyre,going from side to side,especially at the sides,everyone probably thinks im a numptie for doing this but it just gives me piece of mind:-)

>> Edited by rumpelstiltskin on Thursday 8th December 17:08

[nords]

If it is just heat cycles to scrub it in, then why do some bike owners have massive chicken strips? There must be a scrubbing in factor by leaning it over too?

Agreed on the temperature on trackdays, Donnington trashed my diablo corsa. I'm on 4-5mm in the centre and about 2mm at the 45 degree angle on the right hand side, left hand side was trashed too but the only lefthanders are Craners and the corner before the start/finish straight.

[dern]

nords said:

If it is just heat cycles to scrub it in, then why do some bike owners have massive chicken strips? There must be a scrubbing in factor by leaning it over too?

Getting rid of the releasing agent is a different thing from leaving a bit of the tyre unused - I think.

[catso]

Don't know the science but I just take it easy for the first 50 miles or so, gradually building up cornerspeed.

[nords]

Just about scrubbed!!!