• Welcome, Guest! We hope you enjoy the excellent technical knowledge, event information and discussions that the BMW MOA forum provides. Some forum content will be hidden from you if you remain logged out. If you want to view all content, please click the 'Log in' button above and enter your BMW MOA username and password.

    If you are not an MOA member, why not take the time to join the club, so you can enjoy posting on the forum, the BMW Owners News magazine, and all of the discounts and benefits the BMW MOA offers?

  • Beginning April 1st, and running through April 30th, there is a new 2024 BMW MOA Election discussion area within The Club section of the forum. Within this forum area is also a sticky post that provides the ground rules for participating in the Election forum area. Also, the candidates statements are provided. Please read before joining the conversation, because the rules are very specific to maintain civility.

    The Election forum is here: Election Forum

Low temps = lower traction, and a low side!

ANDYVH

New member
I work part time at the local BMW dealer in the Green Bay area, Nick's BMW. One of the best parts of working there is I am the main demo lead rider. When customers come in for a demo ride, I lead them on a preset route in the area around the shop. We do demo rides late into the season as long as the roads are clean. Saturday, at about 3pm a customer came in to test ride a used K1200LT. Rather than get out one of the other demo bikes to ride, I told the shop owner I'd ride my own bike since I rode in that day anyway.

The demo route I do has a few turns so the test rider can at least get some idea of how the bike ridden handles. Some of the turns are simply 90 degree county highway to county highway, others are two-lane backroads with moderate easy turns. The temps were low, about 35 degrees, and the following rider was riding slow and very cautiously, so I backed off my pace to match his. About four miles from the shop was the first 90 degree turn, one I had taken MANY times through the season, sometimes at "enthusiastic" levels because I know the turn and bikes so well. So I backed off what I thought was enough. Wrongo!!

I entered a right hand 90 degree turn, braking done, in 2nd gear and setup for the turn/steady throttle, pressed firm on the right grip to set the bike into the turn, and the front tire totally washed out into a lowside! I'm sliding briefly on the pavement, maybe rolled once, watching my bike slide and spin on the RH saddlebag and valve cover. DAMN! Everything came to a stop quickly, riding gear scuffed, bike still runnning on its side, I'm fine. It was maybe a 30mph lowside at most. I got up and ran to my bike, shut it off, then picked it up. The following rider caught up to me saying "Wow! I just saw you go down! You ok!!??" Yeah.

I briefly looked over the bike, checked myself, looked over the turn, and found nothing to cause the lowside. Got the bike started and we completed the demo ride, while in my head I am trying to figure out what I did wrong. I had taken that same turn MANY times in the past FAR more spirited than I had just done. All I could think was, cold tires. After about an hour back at the shop, I rode back out to the turn, with a infrared thermal reader with me. Before I left the shop I checked the front tire, 20 degrees (center of the tread) on 27 degree pavement (oh by the way, NO frost or moisture involved). I rode the four miles to that turn and stopped there, checked the tire again. Center of the tread was already at 55 degrees, not bad. BUT!! The RH side of tread, just 1.5" off center, that I had leaned into was ONLY 25 degrees! 30 degrees cooler!! As I suspected, cold tire with less grip. The rear tire was at 55 degrees, and 45 degrees off center.

I rode back to the shop, another four miles. Got off the bike and the front tire was already at 75 degrees in the center of the tread. But 1.5" off center it read only 54 degrees, still at least 20 degrees cooler. If I had more time I would have ridden 10 miles, then 15 miles, then 20 miles, and each time taken readings on the tread center and off center to see how the front tire builds heat. My tires are new Avon Storm sport-touring tires with maybe 2,000 miles on them. Good tires, well rated for grip, with variable compounds in the material for better grip off center. But, I did not get enough heat into the WHOLE tread to take that corner like I did. So what was learned from this?
1. If you ride in cold weather, ride conservatively for at LEAST ten miles before expecting ANY normal grip.
2. Even after ten miles, off center of your front tire may be considerably cooler than the center.
3. BACK IT OFF, until your brain is "warmed up" for the ride as much as your tires. Or perhaps, COOL your brain and actions until your tires have warmed up.

So now I have to do some ebay shopping for a used RH valve cover. New winter project also to repair the RH saddlebag. Spend some bucks on getting my scuffed jacket and riding pants repaired. Reset my ego, perhaps do a little reality check in my noggin. And say "thanks, Lord" for the protection of riding gear that let me learn from a low-side witout even a scrath or bruise. Rememer, learn from EVERY ride. good and bad.
 
Glad your OK. Your info is a good reminder of everything needs a warm-up. Gary
 
A buddy went down in NH a couple of weeks ago, frost on the road. Warm tires don't help that.
 
Yeah, this is the time of year when low temps and humidity in the air can put that layer of frost on the surface. No big deal in a car for the most part, but even a small patch of frost in the wrong place can wreak havoc on a bike.

If you are a cold weather rider you have to be aware of all these factors. Even last night, in east central Wisconsin the temps got up over 40 degrees. But it was a somewhat humid day, and when the temp dropped there was a heavy layer of frost on many lighter travelled roads. I was in my car for that drive though.
 
Good info for cold weather riding. Thanks for sharing to allow some of us to learn from your misfortune. Glad your OK.
 
Thanks, Andy, for your careful and useful observations. Glad you weren't hurt.

It's been cold (relatively speaking!) around here the last week; 41?? when I left home today, 35?? when I got to work. And it wasn't ten miles, either: my bike's tires were surely not ready for anything beyond tiptoeing along.
 
Very interesting! Any explanation how the "cold" tire could register only 20 degrees when the pavement was 27 and the air temp about 35? I would have thought that tire temp, after sitting long enough, would equal the air temp.

Anyone know what "ideal" temp is for street rubber? My guess is that in cold weather we NEVER have as much traction for cornering or stopping as in summer heat because we never reach that ideal temperature, even if we drop tire pressure 2-3 psi.

Further food for thought: what is your traction equation when riding on roads which are both cold and wet? My guess, again, is that it is a LOT less than when riding on a warm wet road.

Pure conjecture on my part. I do think this thread opened up a safety issue which has not received the print discussion it deserves. If there is scientific data on these questions (and I bet there is) it deserves wider circulation.

Thanks to the OP for sharing his experience and observations. Hope this thread will garner more information on an important but often overlooked topic.
 
My hope is to present my findings to Avon tire and see if they have any supporting data. But, in this lawsuit happy land of ours I bet they will be hesitant to share. I was not harmed in any way, in fact I am far more sore from raking/gathering the leaves on my 1/2 lot here in Green Bay than from my little get-off. That was three days past I feel nothing and have no bruising.

If I can get any corrobative data from Avon to go with my results then it would be good info for many riders on this forum. At first I was really ticked that I missed something and goofed on my riding. Actually I still am, but if we all can learn something from this its not all a loss.

As to your question, on wet roads I concentrate on smooth actions and limit any control input that destabilizes the bike, even on throttle, clutch, shifting and braking actions. That is one reason why this caught me, because I have ridden on wet roads in high 30's temps many times. This turn was not wet, the day and the air was dry (low humidity), there was no film of dust on the road (that I could find), no obvious debris or winter car droppings (common in these parts), the sun had been shining on the road all day. So to me that leaves cold tires as the traction limiter.

Yeah, that temperature differential was very curious. I would have assumed the tire tread surface would have been the same temp as the air or the surface it was on. Now, my bike was on the centerstand before I took off. I took a tire temp reading at the leading (front) point of the tire, not just above where it contacted the surface. I may check that again when I get another go at this.
 
I have been running tire pressures in the 40 front and 42 rear range for years now, with no other adverse affects prior to this event. So I won't consider tire pressure to be at fault. At the lowest, my tire pressures "may" get down to the low 30's at worst.
 
I entered a right hand 90 degree turn, braking done, in 2nd gear and setup for the turn/steady throttle, pressed firm on the right grip to set the bike into the turn, and the front tire totally washed out into a lowside! I'm sliding briefly on the pavement, maybe rolled once, watching my bike slide and spin on the RH saddlebag and valve cover. DAMN! Everything came to a stop quickly, riding gear scuffed, bike still runnning on its side, I'm fine. It was maybe a 30mph lowside at most. I got up and ran to my bike, shut it off, then picked it up. The following rider caught up to me saying "Wow! I just saw you go down! You ok!!??" Yeah.

That is NOT approved R1100RS riding style. 10 demerits, and go to your room. :)
 
Very interesting post, I'm glad you are okay! Since I got a BMW I have been riding much later in the year and I have lately been thinking a lot about how cold weather affects traction. Thanks for the info.
 
Yes, I had recently thought of the calcium chloride as a new possible danger to motorcyclists. Last week, with an expected sudden drop in temps, both Green Bay and Depere (directly south of Green Bay) road crews were wetting the streets down with the liquid calcium chloride applied behind a sprayer truck.

I came across the stuff in my car, about two blocks behind the truck. At first I thought "what the heck, they're spraying water on the streets and bridges!?" Then it dawned on me its that new application. But this instance of my recent lowside, being on a county two lane highway, it was not the case of anything that I could tell had been applied to the road. It looked clea and normal to me.

But it does bring up a new aspect of possible low traction issues when you don't expect it. The application of calcium chloride applied wet, on dry roads, on days when you would not expect a sudden decrease in traction. Something new we all have to watch for if your riding season extends into late fall/early winter in locales where road crews are trying alternatives to road salt.
 
Very glad to hear that you are OK and providing us with all this information. This really has the makings of a good article for next fall's ON. Great stuff - tire temps, road temps etc...
 
Very glad to hear that you are OK and providing us with all this information. This really has the makings of a good article for next fall's ON. Great stuff - tire temps, road temps etc...


I agree! As I said in responding to your PM to me the other day on this subject, this is great material for a MotoSafe article.

Especially when you consider that right now, your information is only exposed to this subterranian world we call 'The Forum.'

After all, with around 1,700 registered users, that's less than 5% of the MOA membership; 95%+ are still waiting to hear your story.

Stop posting and start writing - I am looking forward to picking up a future issue of ON and reading about your incident and research in detail! :type
 
Last edited:
Very interesting! Any explanation how the "cold" tire could register only 20 degrees when the pavement was 27 and the air temp about 35? I would have thought that tire temp, after sitting long enough, would equal the air temp.

This was exactly my thought too. Weird.
 
Hopefully I can get some tire temperature explanations from the tire makers. Maybe they can explain that weird temperature differential from the surface, air temp and tire surface temp. I would think that being black, the tire would naturally have the same or even slightly higher temperature than the air temp.

Next time I'm in the shop I'll point that same infrared temp reader at the underside of my tongue and see if it calibrates to 98.6 degrees. I should have done that before checking any other values just to see if the gauge was accurate to begin with.
 
I would think that being black, the tire would naturally have the same or even slightly higher temperature than the air temp.

That's true. Our cars have TPM and when parked facing east or west on a sunny day, the tires on the south side of the cars will read several degrees higher than the north ones.
 
Temperature differences

I'm a product of the Tennessee public school system, so this could be all wrong.

Could the temperature differences between surface, air and tire be due to wind chill?

At an ambient air temp of 35 degrees with a 60 mph wind (or for a tire travelling down the road at 60 mph), the wind chill is 17. So, the tire surface is cooled from the "wind chill" affect. The tread in contact with the road (middle) starts to warm first from the friction, but the tread on the side could still be cold from the wind speed.

Just a guess.

piperjim
 
Back
Top