MotoHouston.com MotoHouston.com
Register Members List Member Map Media Calendar Garage Forum Home Mark Forums Read

Go Back   MotoHouston.com > General Discussion > General Discussion (Moto Related)
Forgot info?

Welcome to MotoHouston.com! You are currently viewing our forums as a guest which gives you limited access to the community. By joining our free community you will have access to great discounts from our sponsors, the ability to post topics, communicate privately with other members, respond to polls, upload content, free email, classifieds, and access many other special features. Registration is fast, simple and absolutely free, join our community!

Register Today!

If you have any problems with the registration process or your account login, please contact us.


Like us on Facebook! Regular shirt GIVEAWAYS and more

Advertisement

Reply
Share This Thread: 
Subscribe to this Thread Thread Tools
Old 01-19-2013, 12:58 PM   #21
Bald 'n Gimpy
What?
 
Bald 'n Gimpy's Avatar
 
Join Date: Jun 2012
Location: SW side
Feedback Rating: (4)
Posts: 961

Experience: 10+ years
Trackdays: 10+











Good post! ^^^


And thanks for re-explaining the "greasy" feel
Bald 'n Gimpy is offline   Reply With Quote
Similar Topics
Thread Thread Starter Forum Replies Last Post
Temperature? flipstyledsm22 How To's and Q & A's 4 10-23-2011 10:46 PM
Temperature sensor issues? Phiber General Discussion (Moto Related) 1 08-09-2010 01:14 PM
Air Temperature vs. Tire Grip Bevo General Discussion (Moto Related) 33 10-30-2009 02:52 PM
Temperature on bike lnghrn4lif General Discussion (Moto Related) 6 06-09-2009 09:00 AM
temperature stickers Mad Max Dirtbikes, Mini's, ATV's..... 0 08-11-2007 03:19 AM
Advertisement
Old 01-19-2013, 03:25 PM   #22
Volfy
Fava Beans & a Chianti
 
Volfy's Avatar
 
Join Date: Dec 2011
Location: SW Houston
Feedback Rating: (0)
Posts: 3,504

Experience: 10+ years
Trackdays: 1

Bike(s):
'15 300RR
'15 250XCF-W
'14 Trophy SE
'10 VFR1200F
'05 GSXR600 (track)

Member Garage





Quote:
Originally Posted by Bevo View Post
img battlax s20 03

This is why you don't want your tires to get too hot. The lower the PSI, the higher the temperature.

http://www.bridgestone.com/products/...ttlax/s20.html
I am guessing some of you may be misinterpreting the graph here. All that Bridgestone is illustrating is that s20 offers higher grip vs. 016 over a widerange of tire temps. It's a qualitative illustrating, not a quantitative one. Besides, it only shows the upper part of the tire temp range. The actual full spectrum graph would resemble a bell curve, as "grip" decreases towards the low temp end. All tires exhibit similar characteristics.

Not shown, however, is the grip vs. Slip angle curve, which is actually more telling of the tire's feel to a sport rider who can exploit its limits. Tract and race tires typically yield high grip right up to the limits, but breaks traction sharply at the limits. Street tires typically gives up grip gradually, giving the less experienced rider plenty of warning to back off.

Food for thought next time you go tire shopping. Better equip yourself according to your honest ability than to buy instant "street cred".
Volfy is offline   Reply With Quote
Old 01-19-2013, 04:28 PM   #23
Bevo
Hook 'em!
 
Bevo's Avatar
 
Join Date: Mar 2009
Location: Houston-The South Loop
Feedback Rating: (0)
Posts: 24,295

Experience: 10+ years
Trackdays: 3

Bike(s):
'12 CBR1000RR Red/Black
'14 CB1000R Matte Gray
'10 CBR1000RR (destroyed)
'09 CBR1000RR C-ABS (sold)
'09 CBR600RR C-ABS (sold)

Member Garage





Quote:
Originally Posted by Bald 'n Gimpy View Post
I'm surprised YOU, Bevo of all people, would start yet another thread for this. There's even been a discussion about the "oils in tires" coming up to surface making tires seem slippery.
Point me to a thread where someone has posted a graphic from a tire manufacturer. I was just passing on info that I already knew, and you know good and well there's a noob born everyday.
__________________
Quote:
Originally Posted by bumblebee View Post
"I lack skillz"
Bevo is offline   Reply With Quote
Old 01-19-2013, 04:28 PM   #24
Bevo
Hook 'em!
 
Bevo's Avatar
 
Join Date: Mar 2009
Location: Houston-The South Loop
Feedback Rating: (0)
Posts: 24,295

Experience: 10+ years
Trackdays: 3

Bike(s):
'12 CBR1000RR Red/Black
'14 CB1000R Matte Gray
'10 CBR1000RR (destroyed)
'09 CBR1000RR C-ABS (sold)
'09 CBR600RR C-ABS (sold)

Member Garage





Quote:
Originally Posted by Volfy View Post
I am guessing some of you may be misinterpreting the graph here. All that Bridgestone is illustrating is that s20 offers higher grip vs. 016 over a widerange of tire temps. It's a qualitative illustrating, not a quantitative one. Besides, it only shows the upper part of the tire temp range. The actual full spectrum graph would resemble a bell curve, as "grip" decreases towards the low temp end. All tires exhibit similar characteristics.

Not shown, however, is the grip vs. Slip angle curve, which is actually more telling of the tire's feel to a sport rider who can exploit its limits. Tract and race tires typically yield high grip right up to the limits, but breaks traction sharply at the limits. Street tires typically gives up grip gradually, giving the less experienced rider plenty of warning to back off.

Food for thought next time you go tire shopping. Better equip yourself according to your honest ability than to buy instant "street cred".
Bingo
__________________
Quote:
Originally Posted by bumblebee View Post
"I lack skillz"
Bevo is offline   Reply With Quote
Old 01-19-2013, 04:42 PM   #25
Bald 'n Gimpy
What?
 
Bald 'n Gimpy's Avatar
 
Join Date: Jun 2012
Location: SW side
Feedback Rating: (4)
Posts: 961

Experience: 10+ years
Trackdays: 10+











Quote:
Originally Posted by Bevo View Post
Point me to a thread where someone has posted a graphic from a tire manufacturer. I was just passing on info that I already knew, and you know good and well there's a noob born everyday.
Word!!!





I'm on same side, Bevo
Bald 'n Gimpy is offline   Reply With Quote
Old 01-19-2013, 09:17 PM   #26
brian1570
Incognito
 
brian1570's Avatar
 
Join Date: Jul 2012
Feedback Rating: (0)
Posts: 1,159

Experience: 10+ years

Bike(s):
07 Dynasaur
09 GSXR600(sold)
06 CBR600RR(wrecked)
04 Buell lightning(sold)
08 nightster(sold)






Quote:
Originally Posted by Bevo View Post
Point me to a thread where someone has posted a graphic from a tire manufacturer. I was just passing on info that I already knew, and you know good and well there's a noob born everyday.
hence the newbie title.








yeah. i know. i'm smart as .
brian1570 is offline   Reply With Quote
Old 01-22-2013, 07:20 PM   #27
r6racer
track
 
r6racer's Avatar
 
Join Date: Dec 2012
Location: Houston
Feedback Rating: (4)
Posts: 8,582

Experience: 2 years
Trackdays: 10+

Bike(s):
2008 Yamaha R6 Race/track
2012 Yamaha WGP R6
2004 Kawasaki KLx250 2-stroke
2008 Yamaha R6 Street *Sold*
2005 Yamaha R6 Track *Sold*

Member Garage





dang i have 30 rear and 20 front
__________________
r6racer is offline   Reply With Quote
Old 01-22-2013, 07:25 PM   #28
Neon Samurai
3090 MotoGP Champion
 
Neon Samurai's Avatar
 
Join Date: Mar 2012
Location: Kings Landing
Feedback Rating: (0)
Posts: 3,221

Experience: 10+ years

Bike(s):
2010 Ducati Streetfighter (sold)
2012 Triumph Speed Triple R
2008 Triumph Sprint ST (Sold)
2014 BMW s1000R
2012 Aprilia Tuono (sold)






i road with a guy whos tire was at 12 PSI
__________________
ASSASSINO
Neon Samurai is offline   Reply With Quote
Old 01-23-2013, 06:08 AM   #29
Bevo
Hook 'em!
 
Bevo's Avatar
 
Join Date: Mar 2009
Location: Houston-The South Loop
Feedback Rating: (0)
Posts: 24,295

Experience: 10+ years
Trackdays: 3

Bike(s):
'12 CBR1000RR Red/Black
'14 CB1000R Matte Gray
'10 CBR1000RR (destroyed)
'09 CBR1000RR C-ABS (sold)
'09 CBR600RR C-ABS (sold)

Member Garage





Quote:
Originally Posted by brian1570 View Post
hence the newbie title.








yeah. i know. i'm smart as .
Do you have a link or graph with street tire operating temps?
__________________
Quote:
Originally Posted by bumblebee View Post
"I lack skillz"
Bevo is offline   Reply With Quote
Old 01-23-2013, 07:06 AM   #30
BYRDMAN
WX MAN
 
BYRDMAN's Avatar
 
Join Date: Apr 2006
Location: Houston
Feedback Rating: (8)
Posts: 9,311

Trackdays: 10+

Bike(s):
2015 KTM Adventure 1190
2007 KTM 300 XC smoker
2007 KTM 300 XC smoker


Member Garage





Quote:
Originally Posted by Bevo View Post
Do you have a link or graph with street tire operating temps?
Man u r really passionate about this shitty graph arent u?
__________________
If you can read this, thank a teacher, because its in English, thank a soldier"

AMERICAN MADE WITH MEXICAN PARTS
BYRDMAN is offline   Reply With Quote
Old 01-23-2013, 07:07 AM   #31
Bevo
Hook 'em!
 
Bevo's Avatar
 
Join Date: Mar 2009
Location: Houston-The South Loop
Feedback Rating: (0)
Posts: 24,295

Experience: 10+ years
Trackdays: 3

Bike(s):
'12 CBR1000RR Red/Black
'14 CB1000R Matte Gray
'10 CBR1000RR (destroyed)
'09 CBR1000RR C-ABS (sold)
'09 CBR600RR C-ABS (sold)

Member Garage





Quote:
Originally Posted by BYRDMAN View Post
Man u r really passionate about this shitty graph arent u?
Thanks for the info
__________________
Quote:
Originally Posted by bumblebee View Post
"I lack skillz"
Bevo is offline   Reply With Quote
Old 01-23-2013, 07:20 AM   #32
SeksualTorture
The left hand path
 
SeksualTorture's Avatar
 
Join Date: Oct 2012
Location: Kingwood
Feedback Rating: (0)
Posts: 108

Experience: 9-12 months

Bike(s):
2003 HD VRSCA V-Rod
1996 GT Pro series Team








img battlax s20 03

^ According to this graph I should consider freezing my tires before racing or figure out some sort of active tire cooling to maximize grip
__________________
15th sig - Pro Patria Vigilans
SeksualTorture is offline   Reply With Quote
Old 01-23-2013, 07:44 AM   #33
BYRDMAN
WX MAN
 
BYRDMAN's Avatar
 
Join Date: Apr 2006
Location: Houston
Feedback Rating: (8)
Posts: 9,311

Trackdays: 10+

Bike(s):
2015 KTM Adventure 1190
2007 KTM 300 XC smoker
2007 KTM 300 XC smoker


Member Garage





Quote:
Originally Posted by SeksualTorture View Post
img battlax s20 03

^ According to this graph I should consider freezing my tires before racing or figure out some sort of active tire cooling to maximize grip


You could fill your tires with LOX or LIN...that should keep em cool
__________________
If you can read this, thank a teacher, because its in English, thank a soldier"

AMERICAN MADE WITH MEXICAN PARTS
BYRDMAN is offline   Reply With Quote
Old 01-23-2013, 07:54 AM   #34
RayBusa
Live Full & Die Empty
 
RayBusa's Avatar
 
Join Date: Feb 2011
Location: Porter & Gunspoint
Feedback Rating: (1)
Posts: 420

Experience: 1-3 months
Trackdays: 1

Bike(s):
06 Busa Street & Track
09 Yammy R1 Track
04 Gsx-r 600 in progress







FYI i use nitrogen air in my tires so i can save weight b/c regular air is lame im fat so i need all the weight reduction help i can find
__________________
RayBusa is offline   Reply With Quote
Old 01-23-2013, 07:55 AM   #35
Bevo
Hook 'em!
 
Bevo's Avatar
 
Join Date: Mar 2009
Location: Houston-The South Loop
Feedback Rating: (0)
Posts: 24,295

Experience: 10+ years
Trackdays: 3

Bike(s):
'12 CBR1000RR Red/Black
'14 CB1000R Matte Gray
'10 CBR1000RR (destroyed)
'09 CBR1000RR C-ABS (sold)
'09 CBR600RR C-ABS (sold)

Member Garage





Quote:
Originally Posted by SeksualTorture View Post
img battlax s20 03

^ According to this graph I should consider freezing my tires before racing or figure out some sort of active tire cooling to maximize grip
Well, you are on a HD
__________________
Quote:
Originally Posted by bumblebee View Post
"I lack skillz"
Bevo is offline   Reply With Quote
Old 01-23-2013, 08:00 AM   #36
grsa
Senior Member
 
grsa's Avatar
 
Join Date: Sep 2010
Location: West Houston-Katy
Feedback Rating: (0)
Posts: 4,433

Experience: 5 years
Trackdays: 2

Bike(s):
V-Strom 650
Triumph Sprint ST 1050
Moto Guzzi Breva 750ie







I think this is the first time I have seen knuckleheads used in an MH post. .
I understood the graph that there is a point where tires get a certain temp the grip starts to decrease and as pointed out, the lower the psi, the temp will be higher and grip lost. Always a good reminder to check the psi before a ride.
grsa is offline   Reply With Quote
Old 01-23-2013, 08:05 AM   #37
SeksualTorture
The left hand path
 
SeksualTorture's Avatar
 
Join Date: Oct 2012
Location: Kingwood
Feedback Rating: (0)
Posts: 108

Experience: 9-12 months

Bike(s):
2003 HD VRSCA V-Rod
1996 GT Pro series Team








Quote:
Originally Posted by RayBusa View Post
FYI i use nitrogen air in my tires so i can save weight b/c regular air is lame im fat so i need all the weight reduction help i can find
As far as I am aware the main difference between nitro and regular air is that nitrogen molecules are bigger. That means air escapes faster from tires, and nitro stays in your tires longer. If there is a weight difference it would be so miniscule that there would be no discernable difference.

Quote:
Originally Posted by Bevo View Post
Well, you are on a HD
hello police, i think i just got trolled.
__________________
15th sig - Pro Patria Vigilans
SeksualTorture is offline   Reply With Quote
Old 01-23-2013, 08:46 AM   #38
Bevo
Hook 'em!
 
Bevo's Avatar
 
Join Date: Mar 2009
Location: Houston-The South Loop
Feedback Rating: (0)
Posts: 24,295

Experience: 10+ years
Trackdays: 3

Bike(s):
'12 CBR1000RR Red/Black
'14 CB1000R Matte Gray
'10 CBR1000RR (destroyed)
'09 CBR1000RR C-ABS (sold)
'09 CBR600RR C-ABS (sold)

Member Garage





Quote:
Originally Posted by SeksualTorture View Post
As far as I am aware the main difference between nitro and regular air is that nitrogen molecules are bigger.
Quote:
What are the effects of using pure nitrogen to inflate tires?

•Nitrogen is a gas and is still affected by changes in ambient temperature (about one psi for every 10° Fahrenheit). Nitrogen filled tires will require pressure be added during the fall/winter months as ambient temperatures and tire pressures drop. Nitrogen is good but can't change the laws of physics.

•Nitrogen reduces the loss of tire pressure due to permeation through rubber over time by about 1/3. This helps maintain the vehicle's required tire pressures a little longer, but doesn’t eliminate the need for monthly tire pressure checks. This is good for people who don’t maintain their vehicles well.

•Nitrogen is non-corrosive and will reduce oxidation and rust due to the absence of oxygen and moisture. This will help minimize wheel corrosion to promote better bead sealing. Tires that are used routinely will be replaced long before any life benefit would be received by using Nitrogen. This is most beneficial for drivers who drive their vehicles infrequently (car collectors, track drivers, snow tire users, motor home owners, etc).

•Nitrogen is a dry gas and will not support moisture that could contribute to corrosion of the tire’s steel components (bead, sidewall reinforcement and belts) due to the absence of moisture over extended periods of time. However it’s important to remember that atmospheric pressure is constantly pushing oxygen and moisture into the rubber from the outside of the tire. This is especially good for low mileage drivers who don't wear out their tires quickly or those that run average annual mileages but use long wearing radial (60K and 80K warranted) tires.

•Nitrogen assures more consistent pressure increases due to increases in operating temperatures in a racing environment because of the absence of moisture. This is especially good for participants in track days, high-performance drivers education schools and road racing.

•Drivers should use standard air if pressure adjustments are required when a local source of nitrogen can’t be found during a trip. While this reduces the benefit of higher nitrogen content, it is far better than running the tires underinflated in search of a source. Often the original nitrogen provider will refill the tires for free or a nominal cost when the driver returns to his hometown.

Rather than pay extra for nitrogen, most drivers would be better off buying an accurate tire pressure gauge and checking and adjusting their tire pressures regularly.
http://www.tirerack.com/tires/tirete...|b|6698650813&
__________________
Quote:
Originally Posted by bumblebee View Post
"I lack skillz"
Bevo is offline   Reply With Quote
Old 01-23-2013, 10:07 AM   #39
clayp
Senior Member
 
clayp's Avatar
 
Join Date: May 2012
Location: Houston
Feedback Rating: (0)
Posts: 401

Experience: 3 years
Trackdays: 3

Bike(s):
2014 Brutale 800
2013 S1000rr
2006 CBR1000rr
2005 Ducati 749s
1993 CBR900rr project






PV = nRT is the ideal gas law. Any increase in temperature yields an increase in pressure, when Volume is kept constant. Also any increase in pressure yields an increase in temperature, when Volume is kept constant. Saying that low tire pressures cause higher temps is incorrect. Using the same tire, at 28psi hot vs 36psi hot the 28psi tire will be lower in temperature driving in the same conditions.

I use a contact pyrometer for my track cars to read temps in the hot pits - ideally you want the temps to be even across the tire from outer tread to central tread to inner tread. If the inner is higher then you bleed pressure. If the outer and inner are higher than the center then you can add pressure.

Tires for track will become loose when too hot or if they have been heat cycled out - too many heating and cooling cycles make the compound less sticky. Different tires have different recommendations for ideal pressures for track - for cars Hoosier tires recommend 40-44psi hot, whereas Michelin Pilot Cups recommend 30-32 hot. Usually this info can be found in the manufacturers white papers on the particular tire compound
clayp is offline   Reply With Quote
Old 01-23-2013, 10:50 AM   #40
Volfy
Fava Beans & a Chianti
 
Volfy's Avatar
 
Join Date: Dec 2011
Location: SW Houston
Feedback Rating: (0)
Posts: 3,504

Experience: 10+ years
Trackdays: 1

Bike(s):
'15 300RR
'15 250XCF-W
'14 Trophy SE
'10 VFR1200F
'05 GSXR600 (track)

Member Garage





Quote:
Originally Posted by clayp View Post
PV = nRT is the ideal gas law. Any increase in temperature yields an increase in pressure, when Volume is kept constant. Also any increase in pressure yields an increase in temperature, when Volume is kept constant. Saying that low tire pressures cause higher temps is incorrect. Using the same tire, at 28psi hot vs 36psi hot the 28psi tire will be lower in temperature driving in the same conditions.

I use a contact pyrometer for my track cars to read temps in the hot pits - ideally you want the temps to be even across the tire from outer tread to central tread to inner tread. If the inner is higher then you bleed pressure. If the outer and inner are higher than the center then you can add pressure.

Tires for track will become loose when too hot or if they have been heat cycled out - too many heating and cooling cycles make the compound less sticky. Different tires have different recommendations for ideal pressures for track - for cars Hoosier tires recommend 40-44psi hot, whereas Michelin Pilot Cups recommend 30-32 hot. Usually this info can be found in the manufacturers white papers on the particular tire compound
The ideal gas law your quoted is correct. The application is not. The temp increase when you pump up the tire - even to max allowable - will not raise the tire temp enough for you to notice. You can plug the numbers into PV = nRT to see.

The real reason tires get warmer with less tire pressure has to do with the tire flexing more. If you take a chunk of tire rubber and bend it back and forth quickly, that piece will heat up.

For example, I had picked up a nail driving our SUV one day. By the time I noticed the tail end feeling squirrely, the TPMS came on, so I stopped to check, the nailed tire was nearly flat and HOT to the touch. And that day I had been driving local at no more than 50mph.
Volfy is offline   Reply With Quote
Reply


Thread Tools

Advertisement


All times are GMT -5. The time now is 07:11 PM.


MotoHouston.com is not responsible for the content posted by users.
Privacy Policy