• There has been a recent cluster of spammers accessing BARFer accounts and posting spam. To safeguard your account, please consider changing your password. It would be even better to take the additional step of enabling 2 Factor Authentication (2FA) on your BARF account. Read more here.

Tire warm-up procedure for trackdays: "Food for thought"

Gary J

Gary J

New member
Joined
Nov 29, 2002
Location
South Bay
Moto(s)
Street & Track
Name
Gary
This was originally a response to a post in the "GENERAL" area, but I figured it might do more future good to fellow BARFers if it appeared here in the "TRACKDAYS" area.

Perhaps the moderator of this section of the forum could "STICKY" it, to make it available longterm?

-------------------------------------------------------------------------

TRACKDAY TIRE WARM-UP PROCEDURE/CONSIDERATIONS

The problem of "cold tire crashes" at trackdays is one that seems to show up time and time again, regardless of whether the outside temperatures are in the 60's, or in the 90's+. From the observations that I've seen of trackday/track school crashes over the last 10 years, I'd conservatively estimate that at least 50% of these crashes are in some way related to tires not being fully up to temperature. In hoping that a little sharing of a bit of personal experience on this topic might potentially cut down on this statistic at future trackdays, I'm posting the following.


TRACKDAY WARM-UP SCENARIO #1
(NOT to do version)

Lap 1 of a trackday session (afternoon session):

Rider circulates the track at a moderate and gradually building pace, leaning the tires over off center by the following incremental amounts:

1st right turn: 20%
2nd right turn: 25%
1st left turn: 20%
2nd left turn: 25%
3rd left turn: 30%
4th left turn: 35%
3rd right turn: 30%
etc ..... etc. ...... etc. .......
last left turn for lap 1: 50%
------------------------------------------------------------

Lap 2 of session: (rider assumes after completing one full lap tires are warm)

1st left turn: 60%
1st right turn (Turn 3): 80% ................ (CRASH!!!!)

--------------------------------------------------------------

In this scenario, the problem is that despite the bike having completed a full lap, (or maybe even two laps, if traffic restricted speeds during that time and limited the maximum lean angle incrementally obtained), 50% of the sides of the tires have not yet made contact with the pavement. As such, despite the middle 50% of the tire being relatively "warmed up", the part of the tire that will be called upon to provide traction when leaning the bike that added 30% into the 1st righthand turn on the 2nd lap, will still be "cold". The outcome? The tires let loose just like the bike was starting on its very first corner, on its very first lap ...... because in the view of this previously untouched portion of the tread surface of the tire .... that's exactly how it sees things. Make sense?

The secret to avoid this situation is to recognize the fact that only the portion of the tire that has actually made contact with the pavement up to that point will have developed any heat (i.e "traction potential"). The rider must then make it a religious ritual to never adding in more than a couple of degrees of additional lean angle from one corner, to the next adjacent corner, regardless if it's the first lap of a session, or the second.


TRACKDAY WARM-UP SCENARIO #2
(RECOMMEDED version)
Lap 1 of session:

1st right turn: 10% lean
1st left turn: 10% lean
2nd right turn: 15% lean
2nd left turn: 15% lean
3rd right turn: 20% lean
3rd left turn: 20% lean
etc. ... etc. .... etc. ...

Lap 2:
1st left turn: 50% lean
1st right turn: 50% lean
2nd left turn: 55% lean
2nd right turn: 55% lean
etc. ... etc. ... etc. ...
Last corners of 2nd lap:
95% lean
100% lean

If for some reason (slower riders encountered, excessively cold or any dampness of conditions, etc.) I am not able to incrementally increase the lean angles in those very "baby step" increments in all corners along the way, I will simply make it a point to add another lap to the warmup process before committing to the more extreme lean angles.

Hopefully for those of you that have had the misfortune of experiencing a trackday crash where the lack of full traction being available across the entire width of the tread area of a bike's tires was a primary contributing cause, the application of the incremental lean, two-lap full warm-up procedure I've shared above might be helpful in preventing a future reoccurrence. For those of you fortunate enough to not yet have experienced this, perhaps reading this (and religiously following it in the future) will prevent a first time get-off from this cause ...... for some track-going BARFer(s).

Gary J
 
Last edited by a moderator:
Here's a little more food for thought;

At the AFM races, at Sears at least, they have a hot pit area where you can to warm up the bike,tires and rider. This just consist of riding a loop where you can acclerate, brake, weave back and forth.

I wonder if track day operators would be receptive to this idea.

Doing this and following Gary's advice might have some really good results.
 
ontherearwheel said:
Here's a little more food for thought;

At the AFM races, at Sears at least, they have a hot pit area where you can to warm up the bike,tires and rider. This just consist of riding a loop where you can acclerate, brake, weave back and forth.

I wonder if track day operators would be receptive to this idea.
Click to expand...
It's good to be looking for any methods that might be added to improve the "cold tire crash" situation Ontherearwheel, but unfortunately the "Hot-Pit" area that exists at some AFM race venues, doesn't really provide much help in that area.

This "Hot-Pit" area is really intended (by the AFM) to be used for riders to go slowly while assessing little functional details of their bike (if the brakes feel OK, the steering OK, the tires and wheels OK, everything flows and nothing is coming loose on the bike). The act of "weaving from side to side" is NOT a prescribed behavior in this area to be encouraged by the AFM officials, for riders. Granted you'll still see some racers doing this from time to time ....... but it's usually the less experienced ones.

Roadracing World magazine did a really excellent report/test article some time back, in determining what effect the various methods used by riders had on actual warming of the tire's tread surface temperature.

The test showed that the "weaving from side to side" that riders are sometimes seen doing (mostly novices, that haven't been educated on the various tire warming concepts yet), had almost ZERO effect in actually adding any heat to the tread surface of the tires!

The bike sitting parked in direct sunlight, actually had a very significant impact on the measured tire tread surface temperature ....... especially on clear, warm days of course. Obviously "tire warmers" were the ideal solution for getting temps up in the tires ...... but this isn't practical for most riders to use ..... especially for trackdays or track school events.

Bottom line is that using a smart plan for incrementally leaning the bike over in "baby steps", during the first 2 laps of each and every session back out on track (even if it's the 4th or 5th session of the day, on well scrubbed in tires), is the only real foolproof method that I've found over the years, for minimizing the chances of a "cold tire" crash.

Gary J
 
Good Stuff. Don't forget that lean angle is only one of the factors in warming up. Another is the amount of acceleration out of the turn. If you are still at all on the side of the tire and give it a moderate but safe amount of gas and increase that acceleration throughout the lap then that will also help your tires warm substantially. Especially on any of the larger bikes. Just food for thought.
 
Hey Gary

Are tire warmers a reasonable investment for someone who is only going to run 3 or 4 track days a season?

AND, do you know what they go for??

Thanx
 
Re: Hey Gary

Harpo said:
Are tire warmers a reasonable investment for someone who is only going to run 3 or 4 track days a season?

AND, do you know what they go for??
Click to expand...
Honestly Harpo, unless a person really had a lot of money that was just sitting around, I don't think that the major investment that's involved in making tire warmers part of your arsenal of trackday gear is best choice.

I raced for about 8 years before I finally decided to make the investment into tire warmers, and the required generator to provide power to run them. By simply making it a point of religiously applying the incremental tire warm-up procedure that I described as the start of this thread, I never had any problems with cold-tire crashing.

Regarding the cost ...... I ended up with a set of the "Chicken Hawk" brand of tire warmers .... which I feel are some of the best (and easiest to install/remove) on the market. These warmers run around $425 for the set.

As that AC power to run the warmers is not readily available at the track, adding a generator (that puts out at least 1500-2000 Watts to the list of items needed, really raises the cost. The HONDA "EU-2000" generator is an awesome unit, being very small in size, and whisper quiet (everyone appreciates that at the track, including the owner of the generator) . The list price for it, is over $1,000 ..... but if one does some shopping around, can likely acquire one for around $875-$925.

So doing the math ....... that's about a $1,400-1,500 investment to be ready to go with tire warmers at the track. A nice tool that does make life good for roadracing .... but a bit much for those of us that are "financially challenged" ..... when considering this setup for use at a few trackdays/year.

Your call of course Harpo ..... but that's my take on it ... FWIW.

Gary J
 
And tire warmers aren't a clear silver bullet either.

In last month's RoadRacing World they evaluated several brands of warmers and discussed tire warmer use with several manufacturers and track folks.

Like all things motorcycle related; the variety of opinions was significant (amount of time on warmers, best temp to raise to, etc.) and no clear conclusion could be drawn- except using tire warmers was better than not using them...
 
Re: Re: Hey Gary

Gary J said:
Honestly Harpo, unless a person really had a lot of money that was just sitting around, I don't think that the major investment that's involved in making tire warmers part of your arsenal of trackday gear is best choice.

So doing the math ....... that's about a $1,400-1,500 investment to be ready to go with tire warmers at the track. A nice tool that does make life good for roadracing .... but a bit much for those of us that are "financially challenged" ..... when considering this setup for use at a few trackdays/year.

Your call of course Harpo ..... but that's my take on it ... FWIW.

Gary J
Click to expand...
Just call me Harpo "Financially Challenged" Horowitz.:laughing :laughing
Thanx for the input. I also raced for several years in the late '80's early '90's and no one, but the "big guys" had tire warmers and some how we all survived. And tires are even soo much better now.Then I went to the track this summer after a MANY year hiatus (not racing again but just to watch) to see that almost everyone had them but I didn't realize how much it took to run them. Didn't take the whole generator thing into account.

Thanx for the input and you'll see me out there. I'll be the one running 2 good warm-up laps.
Thanx again,
Joe
 
Question for Dr Jahne

Gary,
Often times I will set the air pressure when it is 40F out like, at ThunderHill, then by 10 AM it is a sunny 65F, I have noticed that even cold the tire pressure tends to rise a reasonable amount--Do you recommend resetting the presure--like after lunch(if it warms up appreciably)---I am wondering if alot of folks are really closer to 35psi when they set the tires at 30psi---on an early/cold morning
 
Re: Question for Dr Jahne

Trackho said:
Gary,
Often times I will set the air pressure when it is 40F out like, at ThunderHill, then by 10 AM it is a sunny 65F, I have noticed that even cold the tire pressure tends to rise a reasonable amount--Do you recommend resetting the presure--like after lunch(if it warms up appreciably)---I am wondering if alot of folks are really closer to 35psi when they set the tires at 30psi---on an early/cold morning
Click to expand...
Good question to ask Trackho, as taking into consideration extremes in ambient temperature at the time one is setting the initial "cold" tire pressure, is something that I feel is appropriate (my opinion only, FWIW, of course).

By "extremes", I guess I view anything below about 50 degrees, and anything above about 90 degrees, as ambient outside temperature where the bike is parked ..... as meeting that "extreme" criteria.

Personally, if I'm setting my tire pressures in the morning, and the outside temperature is say ...... in the 40's, I'll usually set the pressure about 1 PSI (or maybe 2 if it feels really cold) HIGHER than the normal "cold" tire pressures that I normally would run (31PSI front, 29PSI rear, with the Dunlop D208GP's). If possible, I prefer to wait until as close to the moment that the first on-track session is to begin (rather than doing it first thing in the morning), before setting my tire pressures on these colder days .... to maximize the chances of having the warmest of available temperatures present at the time they're being adjusted.

On the other extreme, if for some reason I arrived at the track later in the day, and the outside temperature was already up in the 90's+, I'd likely chose to set my "cold" tire pressures the same variable of 1 PSI (or maybe 2 on an extremely hot day) only setting them LOWER in this case, than the normal target "cold" pressures.

It may not be the "official" correct way, to slightly alter the "cold" tire pressures used for setting one's tires based upon extremes in ambient temperature, if one were to ask the actual Tire Reps ...... but if it isn't ...... that's OK too ..... as it's always worked well for me ...... so I'll stick with it. :)

Disclaimer goes here ......... "YMMV"" ("your mileage may vary") :laughing

Gary J
 
Last edited:
T-ho,

using a very rough approximation (using ideal gas law)...

going from 40F to 65F will yield ~5% change in pressure -- assuming that there is no change in volume.

so if your initial pressure was 30psi at 40F, your looking at closer to 31.5psi at 65F ambient.

of course, it's been a long time...and I'm too lazy to verify my numbers and approach
 
daslowguy 110 said:
hey gary i think that article also stated tha hard braking added more heat than anything on the first lap
Click to expand...
Right on the money Vaughn! I believe that's exactly what the article had noted, based upon their actual pyrometer based temperature testing of the tires.

Anything that makes the rubber surface of the tread flex and move in relation to the pavement surface, creates the friction that results in generating heat into the tire. The flexing of the tire carcass under braking, and the resultant transfer of weight onto the tire (front mostly), certainly serves to produce this form of tread surface to pavement flex.

Gary J
 
nine said:
T-ho,

using a very rough approximation (using ideal gas law)...

going from 40F to 65F will yield ~5% change in pressure -- assuming that there is no change in volume.

so if your initial pressure was 30psi at 40F, your looking at closer to 31.5psi at 65F ambient.

of course, it's been a long time...and I'm too lazy to verify my numbers and approach
Click to expand...

:nerd x10

:twofinger
 
My method of warming the tires is based on generating heat through carcass flex. For most of the first lap, I'm all the way off of the bike, keeping it upright and gassing through turns (no trailbraking) with my foot planted on the outside peg.

I'm at around 30-40% of full lean in my first turn, gradually bringing the bike up to speed.

Second turn, I'm 50-60% of full lean, still babying the throttle.

I keep it at around 50-60% all the way until a part of the track where I can really dial on the throttle. At Infineon, it's Turn 5. Thunderhill, the exit of Turn 6. I use the faster turns to dial on the gas, pile on speed, flex the carcass and generate heat.

I'm at around 80% for the rest of that first lap, taking care to still be cautious on whichever side is colder for the next half lap.
 
You must log in or register to reply here.
Back
Top