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Discussion Starter #1
i see a lot about bike set up and other things that are good for track days or racing, but nothing on tire pressure....tire pressure is a key to keep your tires at the best temperature for adheason to the track....we use to have a dunlop rep at all the loudon races and the best rule of thumb i ever had on tire pressure was the 10% number..

after a session out on the track, immediately check your tire pressure..it should be 10% higher than when u started..if its higher, than your starting pressure is too low and the tire is heating up too much.....if its lower than 10% than your starting pressure is too high and the tire isnt heating up enough

example, before practice or track day..check both pressures..it your at 30 in the front and 36 in the rear then after a practice session your front should be 33-34 and the rear 39-40...if its higher than those numbers then add more air (go up 2 psi) if its lower then go down 2 psi...and check them again before and after the session...

just some 2 cents from gsxrjack
 

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Thanks jack for the info. I have never heard this before. Thanks. :dthumb:
 

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Thanks. I've always wondered how guys know what pressure to select for their tires. But here's a question on that subject. Does the length of the session have anything to do with the percentage increase. Say, a 20 minute session vs. a 30 minute session, etc.
 

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Discussion Starter #4 (Edited)
Captain Morgan said:
Thanks. I've always wondered how guys know what pressure to select for their tires. But here's a question on that subject. Does the length of the session have anything to do with the percentage increase. Say, a 20 minute session vs. a 30 minute session, etc.
no, not for a 20-30 minute session...on our sprint races it was only 10 laps, (around 13 minutes on the 1.6 mile track) at loudon, bridgehampton was a 3.0 mile track and the same rule applie,,also our endurance races ran 3-6 hours and we each rode for 30 minute stints on the bike, only adding fuel and staying on the same tires and never even checked the air pressure...we checked the tires at the end of a practice session and set the pressure according to that......

plus the tires were gone by the 2nd hour anyways so air pressure was the least of our worries :crazy:

also, the Pro;s have temperature readers that can tell the temp of the tire rubber and the pro's will set their pressure according to that, but for us normal privateer riders, the 10% rule works great
 

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Two of the guys I ride with told me to lower the pressure in front and rear about 3 lbs from factory spec. At the speeds we run they were saying it makes the tires last longer and better grip. I can understand the grip part, but would underinflating make them last longer? I know I am ready to try anything, I'm finishing off 3rd set of tires since I bought my f4i in June. And tires ain't cheap!
 

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GsxrJack said:
no, not for a 20-30 minute session...on our sprint races it was only 10 laps, (around 13 minutes on the 1.6 mile track) at loudon, bridgehampton was a 3.0 mile track and the same rule applie,,also our endurance races ran 3-6 hours and we each rode for 30 minute stints on the bike, only adding fuel and staying on the same tires and never even checked the air pressure...we checked the tires at the end of a practice session and set the pressure according to that......

plus the tires were gone by the 2nd hour anyways so air pressure was the least of our worries :crazy:

also, the Pro;s have temperature readers that can tell the temp of the tire rubber and the pro's will set their pressure according to that, but for us normal privateer riders, the 10% rule works great

In the old days they were 10. But Wera and AMA both have gone to a 12 to 15 format.
 

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Discussion Starter #7 (Edited)
twisty said:
In the old days they were 10. But Wera and AMA both have gone to a 12 to 15 format.
well since tire gauges have a 2% error in them , unless your using a tire gauge that costs over $100.00 (1/2% error) stick to 10% cause if your getting a 17% air pressure rise.(15% +2% error) your taking a good chance of over heating your tires and have them get real greasy after 5 or 6 laps...again just my 2 cents from an old fart :rolleyes: ..

and i also should have said a 10% is a good starting point, if you feel there going away due to heat, then add a few pounds, and if you feel there not hooking up due to not getting warm enough then by all means lose a pound or too...your riding ability and style will dictate how much heat your gonna generate in the tires also....10% is just a nice safe starting point to get going on without getting into a lot of trouble..
 

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I called Thompson Gauges and found there is .8% error in the .99 cent gauges you from Auto Zone. Just dont drop it. His name was Walter Davis. I can give you number if you like.Technolgy my friend. If you buy the Digi one, almost no error factor. He said that a 2% error factor was huge and highly doubts unless the gauge was dropped. I love google

My 2 cents from a smart guy
 

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Discussion Starter #10
twisty said:
Im sorry. I walt read the post and wanted to put the percentage as +/- 1%. Their gauge is call the Roadgear Digital Tire Pressure and it is 20 bucks not 100.
ok so the digital gauge u said had almost no error factor now has a +/-1% error, so what does that make the 99 cent one from autozone....besides a pos guage...I deal with transducers that measure pressure's that costs thousands of dollars and they are only guarenteed to +/- 1%...

enough of beating a dead horse...bottom line check your air pressure and make sure your getting a rise in pressure thats not through the roof, or not rising at all...enough from me on this subject
 

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Hungry for more tyre technical info .........

Hi, its the Pink Panther from the UK here, just joined up and searching for information on race tyre technology before taking my GSXR1000 04 to the tracks in April here in England. Does anyone know of any sources of reliable technical data etc on the black art of sticky tyres?

Any info to [email protected] would be most welcome.

Thanks folks,

Pink Panther
 

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Twisty has the same bike and both, he and I, will recommend the Michilin Pilot Powers!!!!!! Best street tire you can get!!
 

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Re: Tire gauges ... they can be off more than 1%. Depending on how you take care of it, it can be as much as 10% (3 lbs +/-) or more. Checking it against the tire vendor at the track is standard protocol, but at track days there may not be a vendor.

The art of reading your tires is more reliable, and not hard to learn. That way you just add or remove air using your gauge ... even if it's 10% off, adjusting 2 pounds with it is only going to have a .2lbs margin of error. If a tire isn't getting hot enough, you reduce pressure. If it's melting, you increase pressure.

Talk to someone who races on a regular basis, or isn't shagging their tires at a track day - they should be able to show you what you want the tire to look like when you come in off the track, and what are indicators of too much pressure, or too little pressure (It's hard to describe in workds, especially without pictures).

Once you know what you're looking for, it's easy to make minor adjustments in pressure to get optimum performance. We adjust pressure throughout the day as the track surface temp is radically different at 8am vs. 2pm, and you need to adjust accordingly if you want the most out of the tires.

- Brian Roach
SpeedWerks.com
 

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Discussion Starter #16
SpeedWerks.com said:
Re: Tire gauges ... they can be off more than 1%. Depending on how you take care of it, it can be as much as 10% (3 lbs +/-) or more. Checking it against the tire vendor at the track is standard protocol, but at track days there may not be a vendor.

The art of reading your tires is more reliable, and not hard to learn. That way you just add or remove air using your gauge ... even if it's 10% off, adjusting 2 pounds with it is only going to have a .2lbs margin of error. If a tire isn't getting hot enough, you reduce pressure. If it's melting, you increase pressure.

Talk to someone who races on a regular basis, or isn't shagging their tires at a track day - they should be able to show you what you want the tire to look like when you come in off the track, and what are indicators of too much pressure, or too little pressure (It's hard to describe in workds, especially without pictures).

Once you know what you're looking for, it's easy to make minor adjustments in pressure to get optimum performance. We adjust pressure throughout the day as the track surface temp is radically different at 8am vs. 2pm, and you need to adjust accordingly if you want the most out of the tires.

- Brian Roach
SpeedWerks.com
since temperature readers have become a lot less money now than when i was racing , (only the big 4 teams used them back then) i would think that would be the best way to check for correct tire pressure/temperature...do you guys use them when racing or just go by the visual look of the tire to see if pressure is correct...
 

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GsxrJack said:
since temperature readers have become a lot less money now than when i was racing , (only the big 4 teams used them back then) i would think that would be the best way to check for correct tire pressure/temperature...do you guys use them when racing or just go by the visual look of the tire to see if pressure is correct...
Maybe we're old-school (or just cheap) ... still go by visual inspection.

Plus ... with track days and amateur racing, most guys don't have a team that can have someone waiting on the hot pit to take a reading as soon as you pull off the track. By the time you've rolled through the paddock (worse if it's not paved, which at several tracks is the case), someone's dumped out cooler icewater, etc, etc ... the reading is not exactly scientific or repeatable.

If you do have someone who can wait for you to come in and get a good reading on the hot pit, absolutely the best thing is a pyrometer.

- Roach
 

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Laser Infared

Does anyone use a laser infared temperature gage? Some are pretty cheap now (aprox $75). If so, what brand and when/where do you check (tire or track surface)?

:bthorse:
 
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