Tyres, Pressures and Backing it in..

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Kwackerz
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#1 Post by Kwackerz » Wed Aug 08, 2007 7:54 pm

Next they sent us to the Pirelli tyre service to have our pressures set … letting about 15 psi out of the rear and 10 psi out of the front (me having set them to the manufacturers road settings the evening before).

Was there the option to refuse their 'help'?
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#2 Post by D-Rider » Wed Aug 08, 2007 8:11 pm

Kwackerz wrote:
Was there the option to refuse their 'help'?
Well, no one was actually checking that you went to the tyre service guys - I guess I could have just gone straight down pit lane - maybe have ended up past the cones and not have had to turn around ..... avoiding my little tumble. There again, based on Pierre's experience, I may then have had a bigger tumble!

Perhaps some compromise pressure is worth a try - but it's probably just that I need to get used to the lower pressures. Mind you, I did notice that not everyone's tyres ripped up in the same way - I wondered whether they were overheating and would not get so hot if the pressures were higher.
There again, I'm running Stradas which aren't really track focussed ......

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#3 Post by Kwackerz » Wed Aug 08, 2007 8:14 pm

I was thinking more of safe but excess wear, tyre guys there.. reduced price tyres... captive audience...

OOPS! Tinfoil hat time! :smt002
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#4 Post by Gio » Wed Aug 08, 2007 8:33 pm

Kwackerz wrote:I was thinking more of safe but excess wear, tyre guys there.. reduced price tyres... captive audience...

OOPS! Tinfoil hat time! :smt002
Must admit if it'd been me I'd not let that amount of air out, as the Falco is a lightweight after the BB which I used to have at 12lbs and 10lbs lighter than road, also ther fact that the Falco turns in faster which must have a bearing on tyre temps.

What do you think?

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#5 Post by Kwackerz » Wed Aug 08, 2007 8:43 pm

The fact it's a V twin'd have a bearing on the temp of the rear at least. all that power snapping out of the bends like Haga used to.. well.. ok..this was DR we're on about. :smt002

I wouldve took em down to about 28 front and.... fks what rear. 32 possibly?

Ive got a book somewhere with the advised pressures for road n track for various bikes. I'll go have a look in the shed... tomorrow..

I'd say Pierre would be the best marker point to go off though.




* but that would be with tyre warmers before it went out on track
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#6 Post by D-Rider » Wed Aug 08, 2007 8:50 pm

Kwackerz wrote:I was thinking more of safe but excess wear, tyre guys there.. reduced price tyres... captive audience...

OOPS! Tinfoil hat time! :smt002
.... the thought had crossed my mind .......

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#7 Post by D-Rider » Wed Aug 08, 2007 8:52 pm

Kwackerz wrote: I wouldve took em down to about 28 front and.... fks what rear. 32 possibly?
That's about where they were - think it was 29 / 31.

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#8 Post by Kwackerz » Wed Aug 08, 2007 8:58 pm

Which'd sit right with them not feeling right. They'd be more proper track pressures, with tyre warmers before you went out on session (the heat obviously raising the pressures from those cold pressures)

Just dug the book out. RSv, Cadwell, on dragon corsas they went for 32 front / 35 rear
I wouldnt see the falco being too far from that to be honest, it's not too far off being a fire breathing racebike really!
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#9 Post by Aladinsaneuk » Wed Aug 08, 2007 9:22 pm

You do most definately need to reduce tyre pressures be fore going on track, it's always debatable as to how much however.
actually, there is a debate about lowering the pressures AT ALL

road tyres are not race tyres - they warm up differently, and are designed differently. Recently I spoke to a knowledgable chap - a professional tyre fitter, and he stated that unless you are going to do a full race type track session - and by that he meant really working the tyres hard, you should leave the tyres set as for the road - think on it, riding on a track is similar to fast road riding for say 30 minutes - and you are running the tyres at the wrong pressure so of course they will bugger up.

I have not checked this, but it makes sense for me - but i WOULD WELCOME OTHERS VIEWS ON THIS please :)

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#10 Post by Kwackerz » Wed Aug 08, 2007 9:39 pm

I found with the TT that I completely trashed my tyres at Brands. it wasnt a really hot day and I didnt ride like Haga (until the end :smt002 )

I did an Inters and wasnt the fastest out there although I did have a moderate shuffle on. Sam will vouch for the fact my rear tyre was completely fkked. It had changed compound to all intents and purposes. I had road pressures in them. They werent knackered thru suspension, purely thru the fact the pressures were set for road, they were too high.

I suppose it depends on how youre going to ride (and how youre going to cool your tyres down) as well.

A road ride is fast and slow, lights, junctions and traffic causing you to slow, keeping the temp and pressures down, on a track youre only doing one thing, riding. corners are smoother, track is better than the road and the average spoeed compared to on a road is liable to be higher, and with it, the amount of heat in the tyres. Youre going to circulate and those temps (and the resultant pressure) is going to be higher.

Dropping the pressure when cold by a bit will help the tyre to cope with that.

If you keep it on road pressures (higher than track pressures) when they get hot, the pressure will rise above normal. That im sure of.

Most superbike / sportsbike / sports tourer tyres are now track orientated. theyre designed partly with the track in mind and as such will expect (if a tyre can expect?) to be lowered for track use. Thats why the R6 cup run lower pressures yet use road tyres.. as do other cups.. They tend to only run 10 mile races (dunno about R6 cup) and take less time than 30 mins. I guess juggling one against the other.. time versus 'thrashedness', they equate to about the same.

..This could be interesting! :smt005

Put me in the 'Lower the pressures' camp.

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#11 Post by Aladinsaneuk » Wed Aug 08, 2007 10:01 pm

may be lower the pressures a little - but not as much as was done here - that was too much i feel - especially for novices....

i think when i take the falco on the track i will drop from 36/42 to maybe 32/38 at the most.. but then I am a slow rider....

it would also depend on the ambient temperature and the distance/time to be covered

perhaps the secret would be to take the pressures AFTER each session - and to use that as a mark to titrate against?

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#12 Post by Kwackerz » Wed Aug 08, 2007 10:06 pm

After a session when theyre hot?

Wouldnt work. The tyre starts cooling as soon as youre into the paddock. That's why you use 'cold' pressures to determine what's right. If you use hot pressures there's too many variables

or are you on about something different?.
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#13 Post by Kwackerz » Wed Aug 08, 2007 10:10 pm

Aladinsaneuk wrote:may be lower the pressures a little - but not as much as was done here - that was too much i feel - especially for novices....
Ithink i;d have to agree.. as I said before, I'd consider that the pressures to run with tyre warmers.

Novice doesnt really come into it. I was a slow absolute novice when i did the inters at Brands. I'd say with hindsight i was the only one using road pressures... mainly cos I forgot to lower 'em.
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#14 Post by Pierre » Wed Aug 08, 2007 10:15 pm

road tyres are not race tyres
doh , I forgot I run (2nd hand) Metzler racetec's and aladinsanes right. Road tyres warm up quicker and offer better grip at lower temeratures. The racer I buy them off says the racetecs can be 4-6psi harder after 8 laps and 'twas him that recommended the 30/30

edit: i know they cool kwakz, but when i was talking to him he said his warmers take the tyres to 75o and when checked after 8 laps with an infrared thermometer in the paddock they were just under 100o but was a hot day though :smt003

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#15 Post by Kwackerz » Wed Aug 08, 2007 10:20 pm

Road tyres warm up quicker and offer better grip at lower temeratures

Which is why you lower the pressures for when the temp rises?

Just batting ideas round..

Wait til Gio comes in with his stopwatch for doing tyre pressures... :smt005
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