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"tire scrub in a myth'?


gig

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That's the opinion of a "race manager", whatever that is.  If you've ever had a brand new tire slip in a turn once, you'll be careful to scrub them in next time.  They definitely do contain a release agent and anyone that thinks the surface of a new tire isn't smoother (less grip) than a tire with 200 miles on it has never seen and compared the surface of a new and used motorcycle tire.  Obviously, I think the guy is wrong.  When my life depends on it, I'll be conservative with a new tire every time. Knoche doesn't care whether we live or die by publishing crap like this.      

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1 hour ago, Bent said:

They definitely do contain a release agent...

 

Most high quality tire brands do not use a release agent today except maybe on the lettering. Michelin does, which happens to be very popular among the sport bikers, so that is important for this group to know, but it is an exception among its competitors.

The Pirelli guy should be concise and state that "Pirelli does not use a release agent", or "race-grade tires" rather than talk in generalities. I suspect cheaper brands may continue to use release agents because it is less expensive then teflon coating the molds, but that admittedly is a guess and reflection of anecdotes I have read.

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I'll continue to be very careful with brand new tires.  Nobody cares about my ass more than I do especially article writers.   

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So, they want you to cook your tires in the warmers up to 165 degrees.

Hey, that's when my chicken on the grill is done too. Easy to remember, LOL.

Having spun a new tire leaving the tire shop with minimal throttle, I'll vote with my right wrist for going easy on a new tire.

Also a cold tire, having spun it up and dropped it, starting out with a right turn from a red light.

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A "race engineers" advice for those who are using "race" tires in track environments. Exactly the thing a street rider does NOT need to follow. I spent 20+ years in motorcycle dealerships/shops and saw more than one fool ignore the advice to be careful for that first 100 miles. 

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22 hours ago, Bent said:

and anyone that thinks the surface of a new tire isn't smoother (less grip) than a tire with 200 miles on it has never seen and compared the surface of a new and used motorcycle tire. 

I don't think the surface of a new tyre being smooth makes any difference when it comes to grip.

I also have never seen traces of mold release agent on brand new tyres. I think what makes new tyres slippery is mechanics handling the new tyres with greasy hands  and tyre mounting lubricant getting on the tread due to carelessness.

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I would agree  that tires today do not need to be 'scrubbed'.  Have mounted and run MANY and never an issue.   However, since they have never been through a heat cycle, it is more critical that they come up to operating temperature before being asked for substantial grip.  Several miles is all it can take to usually get it done.

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Before you know it,

it goes WHAM.......

"But you're here
And you're there
Well there's guys like you just everywhere
Looking back on the good old days?
Well this young old gun says CAUTION PAYS! "

 

:-)

 

 

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Some tires has silicone layer on them that is slippery until it wears off (mould relase), you might not feel it in dry but in wet its risky for sure. The fact that V4Rosso say, dirty hands hold the tires, also help. I have crazy slippery tires as tires I can trust from first meter. The one that was most slippery was a Dunlop Arrowax rear tire I had on my RC24. I went for a short spin after mounting it (dry roads), felt like rear wheel was loose, and as made it to first crossing I made a u-turn just pulling the throttle a little.....ended up taking the wax like coating off the tire whit a knife. After that the tire was ok, but never trusted it 100%!

The one I trusted from first meter was Continentals RoadAttack2 whit its traction skin! Works briliant! Had them on my 5th gen, and the next set was  Michelins PR2 whitch front wheel felt unstable in turns for 50-60 km, then it was 100% trustable.

 

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one way or the other when I hand the keys to a customer that I just put tires on, they all get the "take it easy for 100 mile" speech. at least that way they are far enough away so I don't see them die.

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Have you seen this video from this guy taking delivery of his brand new bike, with new tires (and new gear) ?

I guess I'll remain careful with my new tires for a few km ...

 

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  • 3 weeks later...
On 27 April 2016 at 1:05 PM, V4 Rosso said:

I don't think the surface of a new tyre being smooth makes any difference when it comes to grip.

I also have never seen traces of mold release agent on brand new tyres. I think what makes new tyres slippery is mechanics handling the new tyres with greasy hands  and tyre mounting lubricant getting on the tread due to carelessness.

 

I doubt the cleanliness, or otherwise, of a mechanics hand would have much to do with it, unless they were dripping with oil.

 

I didn't read that original report, but if it's a race mechanic talking about track tyres, on a track, with tyre warmers etc, then it has no relevance to road riding.

 

I was always told by the manufacturers that tyres do definitely need to be 'scrubbed in', i.e. worn in gently until they provide optimum grip and that has also been my experience. Many years ago I collected my new VFR750 and as I left the first roundabout I encountered, without undue provocation the rear tyre let go and caused quite a wobble, but I saved it and was more fortunate than the guy in the video collecting his new bike. Ouch, that's got to hurt, in more ways than one.

 

Also, quite co-incidentally, about 2 weeks ago I put some new tyres on my FireFighter (2012 FireBlade without fairings) and after about 5 miles, while negotiating a roundabout, quite carefully as I was fully aware these were new tyres (I just put them on myself) and with a merest whiff of throttle the rear stepped out, I recovered but it was a typical high-side and as the bike snapped back it threw me in the air, right off the seat. However with a wobble and a prayer I managed to stay on, very surprised by what had just occurred, although probably not as surprised as the cars ahead of me waiting to enter the roundabout and probably in fear of me falling and sliding into them.

 

So both incidents involved new tyres sliding even when taking it quite steadily, on totally dry roads. These are both bikes capable of dragging their hardware along the road with good properly scrubbed in tyres. So yes, with the 'experts' telling me it is so, backed up by my own personal experiences, I would definitely encourage anyone to take it steady on new tyres.

 

As for that race manager? I'd like to see him on a pair of new street tyres, on the road and following his own advice. I think he'd soon change his mind.

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I was at a lecture by the then Director of Racing at Dunlop. The short of it is that when tyres leave the moulds the process is not over. The tyres need to be heat cycled to normalise the internal stresses and finish the "vulcanising" process. As a matter of habit I always wipe over new tyres with a petrol wetted cloth whether it is needed or not.

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Watch the last minute of this video.

My buddy made it 1/4 mile from my house when he lost the front end.

New tires, morning dew on the road surface.

The road goes right curve up the hill, at the top it turns left curve downhill off camber to the right.

His new front tire slid then gripped and high-sided the bike.

14K in damages. It doesn't look bad in the trailer. I wish I had a camera when his baby was on her side.

 

Yes... There are VFRD members who have crashed on my road during a TexasMAC meet.

 

These were Q3's with a current date code.

 

 

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  • 11 months later...

The only part of all this that I can't wrap my head around is, how do you scrub the outsides?  When the bike is leaned at 45 degrees, there is 1G lateral force being applied.  How do you scrub that off ever?

 

If it's a question of a "coating" coming off because the tire was heated up, I get that, but you will only get so far over before you are applying 1G or better against brand new, untouched tire.

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The only part of all this that I can't wrap my head around is, how do you scrub the outsides?  When the bike is leaned at 45 degrees, there is 1G lateral force being applied.  How do you scrub that off ever?
 
If it's a question of a "coating" coming off because the tire was heated up, I get that, but you will only get so far over before you are applying 1G or better against brand new, untouched tire.


Gradually
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I recall MCN (U.S.) did a test where they physically scrubbed tires with abrasives to see if they could break them in before use, results were inconclusive.

 

Kevin Cameron, who I usually believe on faith, stated that new rubber simply needs a few cycles of heating and cooling as they are being used, that it is a chemical process (as Egg commented in this thread a year ago) that gets them to normal performance levels. It's not a matter of scuffing them up.

 

Either way, I take two separate rides of 20 miles or more before really pushing them. Seems to work. 

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Once upon a time I took my R6 out on the track with completely new Dunlop Q2 tires. I went around the first session in second gear until the last two laps, and the tires stuck like glue as soon as I started to push them.

With Avon Ultrasports they felt slippery at first but felt like glue in about 20 miles of street riding.

With Michelin Pilot Power 2CTs they feel like they're good and grippy in 20 miles of normal riding with normal leaning (not "sport mode").

To me it seems like its more an issue of heating them up to operating temperature.

 

Your mileage may vary and an ounce of prevention is better than a pound of cure.

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Having seen a sportsbike leave the local dealer and then go down as the obviously new (you could see the red line on the tread) let go I have always taken it easy.

 

For me it is a case of getting used to a different feel to the tyre profile. For me as a high miler my tyre profile significantly changes, unfortunately motorway use flattens the middle down on the rear.

 

I used to wipe tyres with a thing called "Platten Cleaner", a fluid used to revive the rubber drive wheels on laser printers. you could feel the tackiness of the surface with your finger after that. I can no longer get it so I just wipe over with contact t cleaner and drive carefully for the first 20 - 30 miles, my first commute normally sees to that.  

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All this talk about slippage due to mold release, and temperature with barely a mention of road surface conditions? That's probably a much bigger factor. Areas with high volumes of slow traffic tend to be smoother than backroads. If you like to whack the throttle & lean in parking lots/city streets you are likely gonna go down regardless of how "scrubbed in" your tires are. 

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On 19/5/2016 at 2:28 AM, Egg on Leggs said:

I was at a lecture by the then Director of Racing at Dunlop. The short of it is that when tyres leave the moulds the process is not over. The tyres need to be heat cycled to normalise the internal stresses and finish the "vulcanising" process.

That might explain a weird slow fall over crash a mate had on new Metzeler M5s a few years ago....The tires had only been fitted that morning an we were about 50 miles into a ride up a dry but cold mountain pass when not going at all fast around a tight corner his bike just sort of slowly slipped over mid bend. Confused by the weirdness the fall we felt the tires and found they had a slippery buttery like residue on their surface sort of like the oil in the rubber was rising to the surface....  

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I always scrub them in and take it easy for the first 100 miles or so, regardless of whether it is really needed or not.

It's cheaper than the alternative and doesn't hurt as much.

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