Tire Pressure
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Squid
Joined: Sep 2009
Posts: 72
Tire Pressure
I have been riding Dunlop Qualifiers... have been using stock pressures 36/42. I ride hard (for the street) and am not concerned with mileage/wear, just want best performance. Please let me know if you have been riding with different pressures and what may be good for sporting rides... thanks in advance.
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SuperSport
Joined: Aug 2009
Posts: 684
From: Richmond, VA
i ride on about 32-36 on the street, and 28 on the track.
basically the lower pressure (to a certain point) makes the tires flex more, giving you a bigger contact patch and make the tire heat quicker and get hotter. And at the same time causing quicker wear
basically the lower pressure (to a certain point) makes the tires flex more, giving you a bigger contact patch and make the tire heat quicker and get hotter. And at the same time causing quicker wear
Last edited by jay956; Nov 15, 2009 at 07:38 PM.
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SuperBike
Joined: Mar 2007
Posts: 2,455
From: Williamsburg, VA
?????
Riding with your pressure to low does NOT help cornering. It may increase the contact patch but it also makes it inconsistent. Not to mention it makes turning the bike physically harder to accomplish. It's a bad idea all around, I can't see any positive aspect for doing that.
Riding with your pressure to low does NOT help cornering. It may increase the contact patch but it also makes it inconsistent. Not to mention it makes turning the bike physically harder to accomplish. It's a bad idea all around, I can't see any positive aspect for doing that.
Who are you?
SuperSport
Joined: Aug 2009
Posts: 731
From: Las Vegas, NV
?????
Riding with your pressure to low does NOT help cornering. It may increase the contact patch but it also makes it inconsistent. Not to mention it makes turning the bike physically harder to accomplish. It's a bad idea all around, I can't see any positive aspect for doing that.
Riding with your pressure to low does NOT help cornering. It may increase the contact patch but it also makes it inconsistent. Not to mention it makes turning the bike physically harder to accomplish. It's a bad idea all around, I can't see any positive aspect for doing that.
Or are the MotoGP guys dumb too?
Last edited by Just_Nick; Nov 15, 2009 at 08:53 PM.
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MotoGP
Joined: Aug 2006
Posts: 2,934
From: altoona, pa
It depends on how much you weigh and how hot it is. There is no need to run OEM recommended pressure unless you hauling a passenger and/or additional weight. I weigh 175lbs. and ride the twisties at a good pace and usually leave the house with 30lbs cold in the summer. If it's cold weather, usually 34lbs cold. I am running Q2s now.
Of course you know that the pressure will increase a few lbs as soon as they warm up. Stop and check your pressure with the same gauge and you'll see how much pressure rises when warmed up.
Of course you know that the pressure will increase a few lbs as soon as they warm up. Stop and check your pressure with the same gauge and you'll see how much pressure rises when warmed up.
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Superstock
Joined: Oct 2009
Posts: 344
From: Concord, NC
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MotoGP
Joined: Aug 2007
Posts: 2,547
From: Way Out West
But I'd guess that after a few fast laps those tires are hotter than our VTR tires ever get, and the actual tire pressure is then quite a bit higher than it was cold.
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Back Marker
Joined: Jun 2009
Posts: 155
From: Sudbury ON
Tire pressures at the track is always much lower than on the street. Read the article below and it will explain virtually everything you need to know. The tire vendors at the track will point set you up with the right tire pressure. Each manufacturer will have a different recommended pressure. My last tires were BT002 and I ran with 29 psi front and back. They were the bullocks. Of course, 2 days at the track and they were almost done for. I'm sure by noon on the third day, they would have started getting squirly. Tire life will also depend on how hard you ride i.e. breaking and corner speed and also track temperature, surface conditions, etc. If I ride 2 days in a row at the track, I can generally get another 2500 km on the street since there is plenty of rubber in the center.
This is the second discussion today about track days and it's starting to give me a hard one.
http://www.sportrider.com/tech/tires...ure/index.html
Cheers
This is the second discussion today about track days and it's starting to give me a hard one.
http://www.sportrider.com/tech/tires...ure/index.html
Cheers
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Superstock
Joined: Aug 2007
Posts: 293
yeah man, the lower tire pressures on the track are to compensate for when they heat up. my bt002rs' aim for 32 hot, which turns out to be like 31/29 depending on how cold it is outside. normally i check pressures immediately after coming off a session on the track, and will do it until maybe the 1-2pm session.
id shoot for a little bit firmer than that for the street, mainly to firm up the steering. 34-36 max hot? ive done the high pressure thing to make sure wear is good, but crap, i hate how bad the traction is (on my old dunlop d220's or whatever at least). felt like running on wet concrete with jack purcells. running high pressures on my bt002rs' is pretty pointless. the carcass construction is pretty stiff already, and to stiffen them to that point is just wasting the available traction.
as far as what are good tires, i like the bt002rs (and have heard good things about the bt003rs) for "sport/performance" riding. its a shame wasting them as commuter tires, use bt016's or bt021's for that (the bt016's corner great tho, but they die out pretty quick if pushed hard). anyways, the 00xrs' are the street version of their dot race tires, different compound thats not susceptible to heat cycles and require less heat to get warmed up. these tires id say are great for newer track riders. if you ride hard on the street maybe pp2ct or bt016, my experience is with the bt016--dont see a real need for the bt00x tires, but they do feel great though, very solid carcass that improves feel tremendously.
id shoot for a little bit firmer than that for the street, mainly to firm up the steering. 34-36 max hot? ive done the high pressure thing to make sure wear is good, but crap, i hate how bad the traction is (on my old dunlop d220's or whatever at least). felt like running on wet concrete with jack purcells. running high pressures on my bt002rs' is pretty pointless. the carcass construction is pretty stiff already, and to stiffen them to that point is just wasting the available traction.
as far as what are good tires, i like the bt002rs (and have heard good things about the bt003rs) for "sport/performance" riding. its a shame wasting them as commuter tires, use bt016's or bt021's for that (the bt016's corner great tho, but they die out pretty quick if pushed hard). anyways, the 00xrs' are the street version of their dot race tires, different compound thats not susceptible to heat cycles and require less heat to get warmed up. these tires id say are great for newer track riders. if you ride hard on the street maybe pp2ct or bt016, my experience is with the bt016--dont see a real need for the bt00x tires, but they do feel great though, very solid carcass that improves feel tremendously.
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Superstock
Joined: Apr 2005
Posts: 371
From: No longer in 'The Suck'!!!
Here's what 10psi in a set of Pirelli Supercorsa SC2s looks like:
Oops! They felt a mite squidgy, so I pumped them up to 30psi when I came back in...
And here's what 32 psi in a set of BT016s looks like:
Oops! They felt a mite squidgy, so I pumped them up to 30psi when I came back in...
And here's what 32 psi in a set of BT016s looks like:
Thread Starter
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Squid
Joined: Sep 2009
Posts: 72
So, I asked Dunlop.. the recommend 36/42... and by the way... 42 is the MAXIMUM on the outside of the tire! Then track reps say to be in the 20's.... seems like manufacture manipulation.. why not just tell consumers the RANGES for best use of the tire?
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SuperBike
Joined: Jul 2005
Posts: 1,548
From: MN
I find the whole thing confusing - tire comp's have recs, bike mfctr. have a rec. As far as I can tell the best pressure to run is that which gives the proper temperature across the tread at operating conditions. that is likely to be quite a range depending on ambient temp, road temp, weight load, riding style. On the track you can measure tread temp and that is how pressures are often set, plus feel, or some will measure change in pressure from cold to hot and use that to be sure they aren't too underinflated and getting to much heat build up. Most of us aren't going to do that so we ask. and we get huge range of recs because tires differ and the guys in the know are usually very fast guys which may have no relevance to us.
On most street conditions, going too soft doesn't help as much because you don't need the absolute best grip as track. and going softer just means more heat increase while you spend 90% of your time straight up: thus more wear and less stability (just having more tread on the pavement and more flex). If you are curious, set them cold at a pressure and recheck while hot - and experiment with different pressures. You don't want more pressure increase than 2-4 pounds I believe (but you'd have to check that, I may be recollecting wrong and that is for track).
On most street conditions, going too soft doesn't help as much because you don't need the absolute best grip as track. and going softer just means more heat increase while you spend 90% of your time straight up: thus more wear and less stability (just having more tread on the pavement and more flex). If you are curious, set them cold at a pressure and recheck while hot - and experiment with different pressures. You don't want more pressure increase than 2-4 pounds I believe (but you'd have to check that, I may be recollecting wrong and that is for track).
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MotoGP
Joined: Aug 2006
Posts: 2,934
From: altoona, pa
I believe you just have to use a little common sense and look at max weight ratings as opposed to what you're carrying, be willing to experiment a bit, realize that if you lower pressure as I posted above, you're gonna suffer more wear for a little traction. I make this choice because of the type of riding I do and the fact that I minimize straight line riding as much as possible.
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MotoGP
Joined: May 2008
Posts: 3,452
From: San Clemente, CA
I imagine they are still doing it this way, but when I was in the pits at Riverside Raceway for the Superbike races in the mid '80s, the Honda techs (5 Japanese guys in white jump suits and an American team manager) used a pyrometer to measure tire temperature as soon as Fred Merkel or Sam McDonald came off a practice lap. They would then adjust the pressure up slightly if the tire was too hot. The temp was climbing rapidly on this April morning.
We were selling Michelin tires to the privateers, and we were located right next to the Honda Team. When the privateers asked what pressure to run, we just said, "Honda is running.......".
When I asked him, the team manager gave me one of Flying Fred Merkel's practice tires (Michelin racing slick rear, the last year before the radials) to take back to my Auto classroom in Garden Grove. I left it there when I retired last January. It turned hard as a rock in the last 25 years.
We were selling Michelin tires to the privateers, and we were located right next to the Honda Team. When the privateers asked what pressure to run, we just said, "Honda is running.......".
When I asked him, the team manager gave me one of Flying Fred Merkel's practice tires (Michelin racing slick rear, the last year before the radials) to take back to my Auto classroom in Garden Grove. I left it there when I retired last January. It turned hard as a rock in the last 25 years.
Last edited by VTRsurfer; Nov 22, 2009 at 09:58 PM.
Thread Starter
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Squid
Joined: Sep 2009
Posts: 72
thanks for the help guys - after getting no tire recommendations from Dunlop, they sent me a book of stickers and some advertisements in the mail... let the experiments begin soon with pressures... my buddy has a tire temp gage too... i may now start obsessing on this...
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