Net-Moto :: Community :: Racing :: Thefts :: Racing Videos Sponsor :: Contact
 Forums   Features   Trackdays   Net-Moto   Race Team   CMSP Training   Sponsors   BARF Store   Donate   Terms of Service 
BARF - Bay Area Riders Forum  Home   UserCP   Register   Calendar   Members   FAQ   Search  AMA

Go Back   BARF - Bay Area Riders Forum > Club House > Racers Corner > AFM Forum


Reply
 
Thread Tools Display Modes
Old 06-13-2017, 09:42 PM   #46
Nick
.
 
Nick's Avatar
 
BARF Moderator
Founding Member
Contributor +

Join Date: May 2002
Location: ¯\_(ツ)_/¯
Motorcycles: make vroom noises
Name: .
I like the Michelin slicks if we're talking tires.

I know people complain about front tire grip on the Michelins, but I don't trail brake very hard so it's never been an issue for me at a mid-pack 450 pace (best lap at Round 3 was a low 2:04 and was my first race weekend since 2014).

The rear Michelin grip is excellent IMO.
__________________
BARF Terms of Service: Don't be a jerk.

Last edited by Nick; 06-13-2017 at 09:43 PM..
Nick is offline   Reply With Quote
Old 06-14-2017, 02:21 AM   #47
dangeranger
Rookie
 
Contributor +1%

Join Date: Sep 2012
Location: Sonoma
Motorcycles: '00 SV650 '05 ZX6R '07 R6 '09 DRZ400
Name:
Quote:
Originally Posted by Nick View Post
The 2:00pm session yesterday destroyed the left side of my tire. It was the ONLY session of the day with the sun out and the track actually absorbed some heat about half way through the session.

Did you check/adjust your pressures throughout the day? A lot of people were tearing tires, but I stayed ontop of my pressures and didn't have any issues.
dangeranger is offline   Reply With Quote
Old 06-14-2017, 10:27 AM   #48
Nick
.
 
Nick's Avatar
 
BARF Moderator
Founding Member
Contributor +

Join Date: May 2002
Location: ¯\_(ツ)_/¯
Motorcycles: make vroom noises
Name: .
Quote:
Originally Posted by dangeranger View Post
Did you check/adjust your pressures throughout the day? A lot of people were tearing tires, but I stayed ontop of my pressures and didn't have any issues.
I check them every session before heading out. That session in particular started off cool and overcast, but the cloud cover baked off after being on the track, which resulted in a spike in track temperature.

I still want to hear about the temp gun usage.
__________________
BARF Terms of Service: Don't be a jerk.
Nick is offline   Reply With Quote
Old 06-14-2017, 10:33 AM   #49
Smash Allen
a comedy of errors
 
Smash Allen's Avatar
 
AMA #: 3283336
Contributor ++

Join Date: Dec 2013
Location: Concord
Motorcycles: S1000RR, FZ09, SV650, YZ250F
Name: Chris
Quote:
Originally Posted by Nick View Post
I check them every session before heading out. That session in particular started off cool and overcast, but the cloud cover baked off after being on the track, which resulted in a spike in track temperature.

I still want to hear about the temp gun usage.
What about right after every session? Not saying you could have saved the tire but I am under the impression that it's a good idea to check pressures fresh off the track when they are highest
Smash Allen is offline   Reply With Quote
Old 06-14-2017, 11:45 AM   #50
Nick
.
 
Nick's Avatar
 
BARF Moderator
Founding Member
Contributor +

Join Date: May 2002
Location: ¯\_(ツ)_/¯
Motorcycles: make vroom noises
Name: .
Yeah.... but I have no idea how to use that information to set pressures before heading out. Knowing the hot off the track pressure is great, but how do you use that to set the pressure before putting heat in the tire?

Also, I don't have any pit crew to help check pressures right as I roll into the pit. If I did it myself, the tire would cool considerably after I rolled into the pit, put the bike on the stands, and then took my gloves off to manipulate the pressure gauge.

The tire isn't so bad that I can't heal it. Plus, I'll need a new front and rear before Round 4 anyway so I'm not too worried about it. Tires are a consumable good and won't last forever.
__________________
BARF Terms of Service: Don't be a jerk.

Last edited by Nick; 06-14-2017 at 11:46 AM..
Nick is offline   Reply With Quote
Old 06-14-2017, 12:18 PM   #51
stangmx13
not Stan
 
stangmx13's Avatar
 
Contributor
BrotoGP

Join Date: Feb 2005
Location: San Diego CA
Motorcycles: 04' 600RR, 09' 600RR, 15' R6
Name: Robert
theres nothing that can be said for certain to correlate track temp and tire pressure. everyone rider/bike/track combo is different and will "work" in a diff range of conditions. until u tabulate data for yourself and see what actually works, itd be hard to correctly predict any necessary changes.

Quote:
Originally Posted by Smash Allen View Post
What about right after every session? Not saying you could have saved the tire but I am under the impression that it's a good idea to check pressures fresh off the track when they are highest
for most, theres no point in check hot-off-the-track pressure. most ppl dont have a probe to check carcass temp. manufacturers dont publish operating temps and dont correlate that with pressures. a lot of riders cant generate 100% of the required heat. riders are lazy when it comes to checking and get bad readings. hot pressures should change w/ conditions. the list goes on and on as to why it doesnt work.

at least with tire warmers, u know your tire is within 20F of a temp & pressure combo that the manufacture recommends so that u can actually set the pressure. but surprise... sometimes even those pressure recommendations are wrong. Dunlop tells all their trackday vendors that tire-warmer pressure should be 23psi. but that isnt anywhere close to what anyone races nor what the Dunlop race techs at MA events tell ppl to run.
__________________
BrotoGP Podcast and on Youtube
WERA #513 / AFM #513R / MotoAmerica #513
Follow me on IG @rwpierce13
Thanks to: RiderzLaw Vortex OptimalRacing
stangmx13 is offline   Reply With Quote
Old 06-14-2017, 12:43 PM   #52
Smash Allen
a comedy of errors
 
Smash Allen's Avatar
 
AMA #: 3283336
Contributor ++

Join Date: Dec 2013
Location: Concord
Motorcycles: S1000RR, FZ09, SV650, YZ250F
Name: Chris
Quote:
Originally Posted by Nick View Post
Yeah.... but I have no idea how to use that information to set pressures before heading out. Knowing the hot off the track pressure is great, but how do you use that to set the pressure before putting heat in the tire?

Also, I don't have any pit crew to help check pressures right as I roll into the pit. If I did it myself, the tire would cool considerably after I rolled into the pit, put the bike on the stands, and then took my gloves off to manipulate the pressure gauge.

The tire isn't so bad that I can't heal it. Plus, I'll need a new front and rear before Round 4 anyway so I'm not too worried about it. Tires are a consumable good and won't last forever.


Quote:
Originally Posted by stangmx13 View Post
theres nothing that can be said for certain to correlate track temp and tire pressure. everyone rider/bike/track combo is different and will "work" in a diff range of conditions. until u tabulate data for yourself and see what actually works, itd be hard to correctly predict any necessary changes.



for most, theres no point in check hot-off-the-track pressure. most ppl dont have a probe to check carcass temp. manufacturers dont publish operating temps and dont correlate that with pressures. a lot of riders cant generate 100% of the required heat. riders are lazy when it comes to checking and get bad readings. hot pressures should change w/ conditions. the list goes on and on as to why it doesnt work.

at least with tire warmers, u know your tire is within 20F of a temp & pressure combo that the manufacture recommends so that u can actually set the pressure. but surprise... sometimes even those pressure recommendations are wrong. Dunlop tells all their trackday vendors that tire-warmer pressure should be 23psi. but that isnt anywhere close to what anyone races nor what the Dunlop race techs at MA events tell ppl to run.
Since I am on my first set of take offs I don't have much of any experience
but watching Dave Moss videos on youtube and asking the vendor at the track has helped me fix my tire wear issues

https://www.youtube.com/channel/UCYm...-UeV7U10_48rqw
Smash Allen is offline   Reply With Quote
Old 06-14-2017, 01:26 PM   #53
Nick
.
 
Nick's Avatar
 
BARF Moderator
Founding Member
Contributor +

Join Date: May 2002
Location: ¯\_(ツ)_/¯
Motorcycles: make vroom noises
Name: .
Quote:
Originally Posted by stangmx13 View Post
Dunlop tells all their trackday vendors that tire-warmer pressure should be 23psi. but that isnt anywhere close to what anyone races nor what the Dunlop race techs at MA events tell ppl to run.
Curious what Dunlop techs recommend. I run my Michelins at 30/21.5 and Michelin recommends 30/22.
__________________
BARF Terms of Service: Don't be a jerk.
Nick is offline   Reply With Quote
Old 06-14-2017, 02:58 PM   #54
stangmx13
not Stan
 
stangmx13's Avatar
 
Contributor
BrotoGP

Join Date: Feb 2005
Location: San Diego CA
Motorcycles: 04' 600RR, 09' 600RR, 15' R6
Name: Robert
Quote:
Originally Posted by Nick View Post
Curious what Dunlop techs recommend. I run my Michelins at 30/21.5 and Michelin recommends 30/22.
Dunlop trackday vendors usually recommend 33/23

Dunlop techs at MA events are cagey, hehe. they try to be helpful without giving u the answer, or rather without telling u what your competitors are running. the range ive gotten from them is 34-42 front for everyone and 18-21 rear for 600s. i race on 36/19 90% of the time.
__________________
BrotoGP Podcast and on Youtube
WERA #513 / AFM #513R / MotoAmerica #513
Follow me on IG @rwpierce13
Thanks to: RiderzLaw Vortex OptimalRacing
stangmx13 is offline   Reply With Quote
Old 06-15-2017, 08:15 AM   #55
Daredevil
Modest Max
 
Daredevil's Avatar
 

Join Date: Sep 2005
Location: petaluma, ca
Motorcycles: 08 r4.5 race, 01 ninja 250 street
Name:
Quote:
Originally Posted by stangmx13 View Post
theres nothing that can be said for certain to correlate track temp and tire pressure. everyone rider/bike/track combo is different and will "work" in a diff range of conditions. until u tabulate data for yourself and see what actually works, itd be hard to correctly predict any necessary changes.



for most, theres no point in check hot-off-the-track pressure. most ppl dont have a probe to check carcass temp. manufacturers dont publish operating temps and dont correlate that with pressures. a lot of riders cant generate 100% of the required heat. riders are lazy when it comes to checking and get bad readings. hot pressures should change w/ conditions. the list goes on and on as to why it doesnt work.

at least with tire warmers, u know your tire is within 20F of a temp & pressure combo that the manufacture recommends so that u can actually set the pressure. but surprise... sometimes even those pressure recommendations are wrong. Dunlop tells all their trackday vendors that tire-warmer pressure should be 23psi. but that isnt anywhere close to what anyone races nor what the Dunlop race techs at MA events tell ppl to run.
i half way agree.
I think having more information can dramatically increase you're tire longevity and reduce wear, and avoid issues.

i have a laser thermometer to test the temp of the ground, and a heat guage for the tire carcass to check rubber temp if needed. this cost about 120 dollars for both. by working with Scott with bridgestone, i've accumulated more than enough data to know what my preasures should be on the warmers.

now, to your point about somethings work for some and not for others, and being a range. This is true, but having data points takes a out a TON of guess work. Ya, i run pressures a lb less than guys who weigh 40 more pounds than me, but i can confirm what works better for me because of track temp and carcass temp. took me little less than a year (because we only run in good weather) to gather more than enough data to see what my pressures should be. my pressures range from 24lbs to 34lbs (so far) in the rear off the warmers. it completely depends on the track surface temp.

this is how my data looks
Pressures--------Track temp-----Time of day (this is somewhat a mute point)
24r 75* 8 am practice
26f

as the day heats up, i can constantly check surface temp and bump up, so by the time its 3 pm, and 95 degrees out side, with a track surface temp of 130degree's my tires pressures have gone up to 32-33lbs. i get even wear all day. so by the end of my day, i've logged almost every session depending on weather. it would look as follows. and all i do is keep it in a little binder note pad.

pressure------track temp-----------time of day
24r 75 8am
26f

26r 95 10am
27f

29r 110 11:30am
30f

31r 120 1pm
31f

i've collected data of what was recommended by Scott at bridgestone, and what has worked for me. If i'm suggested 30R pressure when its 130* track temp, and i come in after a session and use the probe to check tire carcass and its 200 degree's, thats way to hot, so I add a lb.

About half a year of personal data, plus the help of Scott at bridgestone and dave moss, i've it pretty damn narrowed down. Moss always recommends higher pressures than I use, but he's 40lbs more than me, so i've learned what works for him won't work for me.

hope this help.

*edit*

for my, i've learned its about a lb of pressure every 10-13 degree's difference in track surface temp. It is imperative to be checking pressures and increasing/decreasing them through out the day depending on temps if you want to be a)faster 2) better tire wear. You don't see fast guys just setting their pressure in the morning session and calling it day.

double edit*

then again, all this could be pointless as I'm not that fast lol

Last edited by Daredevil; 06-15-2017 at 08:38 AM..
Daredevil is offline   Reply With Quote
Old 06-15-2017, 08:55 AM   #56
stangmx13
not Stan
 
stangmx13's Avatar
 
Contributor
BrotoGP

Join Date: Feb 2005
Location: San Diego CA
Motorcycles: 04' 600RR, 09' 600RR, 15' R6
Name: Robert
Daredevil, who told u that 200F carcass temp was too hot? i know that MA SBK guys run >260F on hot days. ya Dunlops vs Bridgestones, but im surprised that your operating temp would be so low. perhaps im conflating carcass temp and surface temp.

are u purposefully trying to maximize tire wear? have u tried maximizing grip instead? are there 2 diff pressures for these and if so, how far apart are they on avg?

do u have data on what doesnt work? like, if its 120F track temp at THill, do u know that 26R tears but 27R wont?
__________________
BrotoGP Podcast and on Youtube
WERA #513 / AFM #513R / MotoAmerica #513
Follow me on IG @rwpierce13
Thanks to: RiderzLaw Vortex OptimalRacing

Last edited by stangmx13; 06-15-2017 at 08:59 AM..
stangmx13 is offline   Reply With Quote
Old 06-15-2017, 09:49 AM   #57
Nick
.
 
Nick's Avatar
 
BARF Moderator
Founding Member
Contributor +

Join Date: May 2002
Location: ¯\_(ツ)_/¯
Motorcycles: make vroom noises
Name: .
Adding pressure as the surface temp increases seems exactly the opposite of what you'd want to do.

__________________
BARF Terms of Service: Don't be a jerk.
Nick is offline   Reply With Quote
Old 06-15-2017, 09:52 AM   #58
Smash Allen
a comedy of errors
 
Smash Allen's Avatar
 
AMA #: 3283336
Contributor ++

Join Date: Dec 2013
Location: Concord
Motorcycles: S1000RR, FZ09, SV650, YZ250F
Name: Chris
Quote:
Originally Posted by Nick View Post
Adding pressure as the surface temp increases seems exactly the opposite of what you'd want to do.

it does seem counter intuitive...but adding pressure decreases tire flex which decreases carcass temps...or at least that is my current understanding
Smash Allen is offline   Reply With Quote
Old 06-15-2017, 06:54 PM   #59
Daredevil
Modest Max
 
Daredevil's Avatar
 

Join Date: Sep 2005
Location: petaluma, ca
Motorcycles: 08 r4.5 race, 01 ninja 250 street
Name:
Quote:
Originally Posted by stangmx13 View Post
Daredevil, who told u that 200F carcass temp was too hot? i know that MA SBK guys run >260F on hot days. ya Dunlops vs Bridgestones, but im surprised that your operating temp would be so low. perhaps im conflating carcass temp and surface temp.

are u purposefully trying to maximize tire wear? have u tried maximizing grip instead? are there 2 diff pressures for these and if so, how far apart are they on avg?

do u have data on what doesnt work? like, if its 120F track temp at THill, do u know that 26R tears but 27R wont?
I don't remember the exact #'s, maybe its over 200 i dont have my notes next to me, but im talking carcass temp, with a probe gauge. Not surface tire temp. the point is i know what things are too hot.

ya, i have data on what doesn't work. ill keep notes and lets say i have pressures too low for track temp, you can see the issues arise. i can see a difference in 1lb of pressure. 27 compared to 28lbs off the warmers will show on the tire. not in a HUGE portion. i.e. tearing compared to not tearing. but 1lb of pressure will see an effect in what the tire looks like.

i generally shoot for maximizing grip.


Quote:
Originally Posted by Nick View Post
Adding pressure as the surface temp increases seems exactly the opposite of what you'd want to do.

if you reverse the thought process, what is the reasoning behind dropping pressure as heat increases? less pressure woudl make the tire have a larger surface area, which would generate more heat into the tire, and too much of that means melting and slipping.

adding pressure allows the tire to expand its surface area, so it won't get as hot. too much pressure, and you won't generate enough heat, so you start slipping. you gotta find that middle area that gets you grip. you wouldn't leave your pit with 50 PSI in 55 degree weather right? Because it won't get hot enough to give you grip.


at least thats how i understand it
Quote:
Originally Posted by Smash Allen View Post
it does seem counter intuitive...but adding pressure decreases tire flex which decreases carcass temps...or at least that is my current understanding

Last edited by Daredevil; 06-15-2017 at 06:57 PM..
Daredevil is offline   Reply With Quote
Old 06-15-2017, 10:09 PM   #60
wanna be racer
Rookie
 
wanna be racer's Avatar
 
2% Contributor

Join Date: Nov 2013
Location: Patterson
Motorcycles: 2004 GSXR 1000 2004 ZRX 1200 2003 XR 100 1987 YSR 50
Name: Darnell
Bias ply tires flex the carcass and create heat. Lower pressure to raise the temp.

Radial tires are designed for the carcass to flex but not generate heat. By increasing pressure the contact patch is smaller. Thus the contact patch has to work harder (slip and/or flex at the surface) and creates heat.

Less pressure makes a bigger contact patch (less slip and/or flex at the surface) so the tire runs cooler. With that, as a tire wears it would need more pressure to maintain the same temp if all conditions stay the same. Less rubber to flex and build heat.

Someone can give you info on their pressure but that is just a ballpark starting point. If rider 1 is 5 seconds a lap faster than rider 2, rider 1 could run higher tire pressure in the rear because he is easy on the throttle and a demon on the brakes compared to rider 2.

Same for gearing, rider 1 could use the same gearing as rider 2 and be much faster.

I run endurance back in Texas. My teammate and I ran different lines, he ran a gear lower than me in most turns. I would use the edge of the tire with more corner speed and he would go in hard on the brakes, drop and turn then shoot off the turns. But our lap times only differed by tenths of a second from each other and we would ride the same bike.
wanna be racer is offline   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -8. The time now is 04:27 AM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2018, vBulletin Solutions, Inc.