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Discussion Starter · #1 ·
Is it heat or simply mileage that scrubs in the tire? Heading to Fontana Speedway tomorrow with new Pilot Powers. Wondering if I should bother running the bike up the canyon first or just rely on the first few slow laps tomorrow. Thanks.
 
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Discussion Starter · #3 ·
Re: Scrubing New Tires (socal)

I found this to be informative:

Scrubbing in tyres is yet another one of those 'black arts' that riders seem to struggle with. Let's get down to basics. A tyre is made in a process known as injection moulding. Meaning a mould or mirror image of the tyre is formed by a tool called a 'die.'

This die is usually in two halves (left and right) and is put together to form the shape the tyre will attain. The rubber is then injected into the die under pressure, causing the rubber to expand and form the shape of the tyre. When the rubber has cooled sufficiently, the mould separates and the newly manufactured tyre is removed.

In order for the tyre to be taken from the mould and not stick to the surface of the die, a mould release agent is used. This agent is the shiny/slippery stuff on your tyre when it's brand new. It's this stuff we need to get rid of as quickly as possible, so we can actually get to the compound of the rubber which enables the tyre to grip to the road.

Racers often use a product called 'tyre buff' (a form of acetone) that when rubbed over the surface of the tyre, takes off the bulk of the mould release agent. This, combined with tyre warmers, makes scrubbing in a tyre a process that takes all of about a lap or so.

On the track, you simply build up the lean angles and the amount of force used progressively until you've used all of the tyre surface and it's up to optimum temperature. Once you've done that, the job is done.

For the road rider, it's a little harder to scrub a tyre in as you have all of the uncontrolled stuff in the environment to deal with as well as your new questionable traction situation. What often happens is the rider decides to 'take it easy' for a period of kilometres in the belief that this will handle it, which is not always true.
What this means to most riders is that they don't lean the bike over much and they are really gentle with the controls. Whilst there's no problem with this initially, if your use of lean angle and force doesn't progressively increase, then the only part of the tyre being scrubbed is the middle. This leaves the edges still with the slippery surface intact. Then, one day, you get into a corner a little too hot and have to lean it over further than you have before. Now you're on the part of the tyre that's not been touched to the road before and there is no grip. Next thing you know you're watching your bike and body parts disappear up the road in a shower of sparks and skin.

The key is in the progressive use of the tyre. When the tyre is new, you have to be very careful and gentle with the controls and how much force you put into it. What you will find is that once a particular part of the tyre has contacted the road, it loses its slippery feel.

If you can imagine the contact patch of your tyre as being an oval shape, then when the bike is upright and on the scrubbed part of the tyre that has been used, the total area has useable traction. When you lean it over just a few degrees for the first time, you will reach the edge of the scrubbed part of the tyre, and a small amount of 'new' tyre will contact the road. You'll no doubt find that this feels a little slippery and your survival instincts spark up, getting your attention a little bit or a lot (depending on just how slippery it felt).

Once that particular part of the tyre has contacted the road, you can go back to that lean angle and you will find that it no longer feels slippery. This is because the mould-release agent has been worn off and it is in essence, scrubbed. You can now lean it a little further so that once again you just contact the edge of the 'new' tyre, which is now further around it.

By doing this, the bulk of your contact patch is always scrubbed tyre that will give you grip. If on the other hand you decide to 'take it easy,' and then find you have to lean the bike over dramatically more than it has been leant before, the bulk of your new contact patch is now a part of the tyre that has never contacted the road before. Chances are, it will suddenly slide away from you.

This can be confusing to riders because they may have done several hundred kilometres of 'taking it easy' and believed that the tyre should be scrubbed in. The truth though, is that you will only wear off the mould-release agent when that part of the tyre contacts the road, and not before.

To scrub a tyre successfully, progressively build up the lean angle and force you place on the tyre until you have used what is available to you. Once you've done that, the tyre will grip well through the remainder of its life on the bike regardless (to a point) of lean angle and force.
 
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Discussion Starter · #4 ·
Re: Scrubing New Tires (socal)

What makes new tires slick, is the coating the use to make them not stick to the moulds. You have to wear that coating off.

What kind of tires are they?

**EDIT** looks like they beat me to it
 
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Discussion Starter · #5 ·
Re: Scrubing New Tires (hank)

Thanks guys for your timely and helpful replies!


Modified by socal at 4:02 PM 3/25/2005
 
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Discussion Starter · #6 ·
Re: Scrubing New Tires (socal)

Tire warmers and 2 turns, 1 left and 1 right and My tires are fine.
 
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Discussion Starter · #7 ·
Re: Scrubing New Tires (sp2pilot)

I usually head to an empty parking lot to scrub in new tires. Only takes a few minutes when it's hot out, and who doesn't love a little kneedraggin between track days


I've had so many people tell me it takes X # of kms' to break in new rubber.
I don't know where that one came from. Progressive leaning works for me.
 
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Discussion Starter · #8 ·
Re: Scrubing New Tires (sp2pilot)

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by sp2pilot »</TD></TR><TR><TD CLASS="quote">Tire warmers and 2 turns, 1 left and 1 right and My tires are fine.
</TD></TR></TABLE>

Yea, but you still have too much slack in your chain.

Ah, shite did I just type that?




Cheers,
D
 
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Discussion Starter · #12 ·
Re: (hearing8)

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by hearing8 »</TD></TR><TR><TD CLASS="quote">You don't see Mladin riding his bike around the parking lot. sp2pilot is right....buy warmers.</TD></TR></TABLE>

my day job isn't racing motorcycles either.

I was talking about new street tires as an example of how quick they break in.
 
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Discussion Starter · #13 ·
Re: ([email protected])

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by [email protected] »</TD></TR><TR><TD CLASS="quote">socal... where were you pitted Sat. @ Fontana?</TD></TR></TABLE>

Garage 79/80. Started the day in group 1 and finished in group 2. I won a giveaway at the 8:00am riders meeting. Where were you pitted?



Modified by socal at 1:49 PM 3/27/2005
 
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Discussion Starter · #14 ·
Re: Scrubing New Tires (hank)

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by hank »</TD></TR><TR><TD CLASS="quote">Racers often use a product called 'tyre buff' (a form of acetone) that when rubbed over the surface of the tyre, takes off the bulk of the mould release agent. This, combined with tyre warmers, makes scrubbing in a tyre a process that takes all of about a lap or so.</TD></TR></TABLE>

"Tire buff", eh? I've never heard of anyone using a chemical for this - with warmers and a warmup lap, it's scrubbed and ready to go.
 
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Discussion Starter · #15 ·
Re: (socal)

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by socal »</TD></TR><TR><TD CLASS="quote">

Garage 79/80. Started the day in group 1 and finished in group 2. I won a giveaway at the 8:00am riders meeting. Where were you pitted?
</TD></TR></TABLE>

Dont know the #, but was the 1st pit building once you drove into the complex.. If you rode level 2, I was the guy on a little Aprilia 250 put-putting down the front straight.
 
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Discussion Starter · #16 ·
Re: (hearing8)

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by hearing8 »</TD></TR><TR><TD CLASS="quote">You don't see Mladin riding his bike around the parking lot. sp2pilot is right....buy warmers.</TD></TR></TABLE>

+1 on the warmers
I did see Mladin driving hisTruck around the parking lot yesterday..
 
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Discussion Starter · #18 ·
Re: (socal)

Okay, I’ll let you race guys know what I got from several top riders with many British championships between them and many TT wins to boot. Scrubbing in a tire is really important, mainly because you want it done edge to edge without taking any life out of the tire. So the answer is relatively simple and if you’ve not done this before then take care…………..lower the pressure in the tyre.; you will not need to go all that fast and you will not need to lean the bike over all that much to get that edge to edge scrub in. The handling will be a little weird but it really does work.

As for tire warmers...get them on real early, get the rims warm and if any heat is lost from the tire, say on the warm up or on the grid, the warm rim will help transfer heat back to the tire. Don’t wait until ten minutes to go, get them on about an hour before.
 
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Discussion Starter · #19 ·
Re: (Harvey T.)

Most all RACE tires these days are cleaned at the factory. Dunlop REAL race slicks come out of a chrome mould and have no mould release compound on them and that is why they look so shinny. They just need to be warmed up to work correctly. As for street tires most brands these days are clean too.
 
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