Cold Weather 211's

[Saltman]

Saw a post on the R10s in cold weather and it made me wonder about the 211s. I have 2 TD weekends left for this year and as of now the weather in the mornings have been around 40 degrees. In case it gets colder as my trackdays approach, I want to be prepared with the info needed.

I am running the 211 GPA DOT tires and I'm curious as to whether I need to change the pressure for the rear to be higher than 23 hot if the track temp is about 40-50 degrees? Also, should I lower the warmers from the 180 high setting to about 140 low to preserve the tire life?

 

[some guy #2]

By the time you get out of the pits and turn the wheel/brake in anger your tire is going to lose a lot of heat. I'd run the warmers lower than normal and work into the first lap or two. No idea on what temp. or pressure though. I guess you could set them hot from the warmers then check them when you come in to see how much it's changed.

 

[Saltman]

Thanks Joe

 

[sobottka]

run your warmers at normal temp and expect cold tearing. do not drop the temp setting on your warmers, this will guarentee cold tearing and a lack of grip untill they come up to temp. run increased pressure to compensate (up to 25 psi hot)

 

[some guy #2]

^There won't be much grip anyway in the first few laps on a cold track. From sitting on the grid until you can start flexing the tire carcass around the track it's going to be slick.

 

[borislav]

In Sept.I destroyed brand new 211GP in medium+ compound in two track days and that incloude fliping it!
I menaged to make 5 track days with 211GP in 6680 (medium) compound and to destroy medium+ in two days was very bad in my opinion,keep in mind I changed nothing but air and track temp.was a lot lower!I called Mr. Steve Brubaker from Dunlop and basicaly he said that cold weather is to blame for!

 

[DUNLOP-RTS]

Saltman;220089 wrote: Saw a post on the R10s in cold weather and it made me wonder about the 211s. I have 2 TD weekends left for this year and as of now the weather in the mornings have been around 40 degrees. In case it gets colder as my trackdays approach, I want to be prepared with the info needed.

I am running the 211 GPA DOT tires and I'm curious as to whether I need to change the pressure for the rear to be higher than 23 hot if the track temp is about 40-50 degrees? Also, should I lower the warmers from the 180 high setting to about 140 low to preserve the tire life?

If it very cold, there is not much you can do to guarantee not to tear. Changing the warmer temp is not going to be effective, simply because the temp of the tire will settle out within the first lap or 2.

Keep in mind that its colder in the morning, and thus more tearing in the AM than in the afternoon. Quite often riders will start to tear a tire in the AM, then make a change (temp, PSI or suspension), then go out later in the day when its warmer and have no tearing issues. Unfortunately they attribute the improvement to their changes (temp, PSI or suspension), when the higher temperature of the afternoon is what is effecting the tearing (or lack of) more than any other factor.

Also, using tires on the harder end of the spectrum are better on colder conditions to reduce tearing. I would not recommend using a softer compound in the cold, better to use a hard. If hard is not available go with the next softer (med).

Cold tracks do not have the same grip level as a hot track, regardless of tire compound choice. Don't complain if things are not as grippy in the cold as in the hot summer. Its a fact of life that every rider must deal with.

 

[Woodcraft]

Just to pitch in with my experience here....Steve is correct. Cold temperatures tear tires....it's not a setup or tire pressure thing. I would run warmers longer in the cold just to be sure that the tire carcass is as heat soaked as possible. We will sometimes wrap blankets around them to help the rim retain heat if it is below 50 degrees.

Harder tires do better in the cold temperatures when it comes to tearing....Steve also mentioned this, and is correct. Even in warmer temperatures there are cases where if it is 70 deg I'll choose a meduim hard and if it's 90 I'll chose a meduim, particularly in a longer race. Of course, different tracks make for different situations, but I only point this out to bring to light that tire compound choice is not always intuitive.

A last note when it is cold out.....get your tires good and hot on the warmers and then get right out and ride. Sitting around will suck the heat right out of them. At some tracks, the worst thing that you can do is to ride easy. I'm certainly not advocating to go out there and ride like a maniac in the cold, but ride smooth and fast...I give myself about 1 second a lap cushion in the cold by trying to be a little smoother than normal and leaving that last bit of margin that perhaps I might not normally leave. Slowing down and cruising around 3-4 seconds off the pace can actually make the tires cool off quicker. I once almost learned this lesson the hard way at a cool night qualifying session Daytona by doing 3-4 laps hard in and then riding around 10-12 seconds off the pace for a lap to wait for a drafting partner. I almost fell off twice trying to go hard on the next lap because my tires had cooled of so much when I started to take it easy. Do your warm up laps at 90% in the cold, and that will help.

Eric Wood

 

[Saltman]

Woodcraft;221503 wrote: Just to pitch in with my experience here....Steve is correct. Cold temperatures tear tires....it's not a setup or tire pressure thing. I would run warmers longer in the cold just to be sure that the tire carcass is as heat soaked as possible. We will sometimes wrap blankets around them to help the rim retain heat if it is below 50 degrees.

Harder tires do better in the cold temperatures when it comes to tearing....Steve also mentioned this, and is correct. Even in warmer temperatures there are cases where if it is 70 deg I'll choose a meduim hard and if it's 90 I'll chose a meduim, particularly in a longer race. Of course, different tracks make for different situations, but I only point this out to bring to light that tire compound choice is not always intuitive.

A last note when it is cold out.....get your tires good and hot on the warmers and then get right out and ride. Sitting around will suck the heat right out of them. At some tracks, the worst thing that you can do is to ride easy. I'm certainly not advocating to go out there and ride like a maniac in the cold, but ride smooth and fast...I give myself about 1 second a lap cushion in the cold by trying to be a little smoother than normal and leaving that last bit of margin that perhaps I might not normally leave. Slowing down and cruising around 3-4 seconds off the pace can actually make the tires cool off quicker. I once almost learned this lesson the hard way at a cool night qualifying session Daytona by doing 3-4 laps hard in and then riding around 10-12 seconds off the pace for a lap to wait for a drafting partner. I almost fell off twice trying to go hard on the next lap because my tires had cooled of so much when I started to take it easy. Do your warm up laps at 90% in the cold, and that will help.

Eric Wood

Thanks for the feedback and advice Steve and Eric. I was riding this past weekend in sub 50 degree weather and found out exactly what you did, Eric, that riding off pace for a while takes the heat right out of them. Unlike in hot weather, due to the track being a much hotter temp, riding off pace won't really take that much heat out of them. But this weekend, in the morning sessions on a cold track, I came around to turn 5 and felt the front push on me two times. Scared me half to death both times and I ran wide trying to keep the bike up. Next week, temps are looking somewhat better for the final trackday at Barber with Nesba. I'm running Mediums and experienced some tearing, but it taught me alot about feel and track temps and heat in tires. I will keep all this useful info in mind. Thanks.