How Much Heat?

Byron

Byron

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Well, this morning I started my testing to see just how much heat the ST1300 rider may be subjected to. Here is how I'm going to do it: I have a small electronic thermometer with internal and external sensors. I ran the external lead down my pant leg to my right ankle. I velcro straped the sensor to the inside of my ankle (sensor exposed to airflow, not under velcro). The digital readout was put in my left front jacket pocket. Jacket is the Olympia Moto Sports Bushwacker in Black/Pewter. It has mesh construction at the pocket.

The air temperature this morning was running about 68 - 70 degrees. Most of the ride was on the freeway but I have about 5 blocks of road before arriving at work. I checked as soon as I parked and the external (ankle) temperature was reading 85 degrees, jacket pocket was at 75 degrees. In the time it took me to put the bike up on the center stand, stow the helment in the bags and put my windshield cover in place the temperatures had changed; external (ankle) temperature was now reading 80 degrees, jacket pocket was at 76 degrees.

Temperature are supposed to reach 90's today so I post more info as I collect it.
 
If you have time I'm also trying to figure out why in the winter time I set the heat for 68 degrees and my wife thinks its cold. But in the summer time if I set the ac for 68 its hot. :confused:

Just one more mystery. Well if you have time :)
 
billxp,

You kind of hit on some of why I'm doing this. Riders say "it's hot" but don't say what the temperature actually is. I know my comfort zones but wanted to see exactly how hot my bike got. Another factor that isn't really clear when they talk about "it's hot" is what the humidity level is. I was in N. Carolina for a bit years ago and temperatures that I was totally comfortable with in California were totally miserable there because of the humidity.

In answer to your problem; because it is :).
 
UPDATE

Well the trip home started out with the air temperature at 86 degrees. I varied the setup just slightly. I discovered that I could mount the thermometer display on the gas tank cap. I used the keyhole cover to hold the display in place so I could monitor temperature changes during the ride home.

Air temperatures ranged from 86 to 90 degrees. Temperatures at my ankle heated up to 102 degrees on surface streets while it was 86 degrees. Freeway temperatures even at surface street speeds was running only about 10 degrees hotter than the air temperature; 88 degrees for the air and low of 94 degrees at ankle. Back on surface steets for the last part of the trip it was 88 degrees for the air and my ankle temperature maxed out at 111 degrees.

It was warm and I was sweating but I would have been doing that simply standing in the sun at this temperature let alone wearing a motorcycle jacket over shirt, tie and slacks. This was only one days data so we will have to check it out further but so far the temperatures were not any higher than you would find in a hot tub. It's true you would normally be wearing less in the tub :D . I also want to check out how hot the faring pockets get so more testing to follow.

Later,
 
Engine heat

Well, the outside temp crossed over 100 today in Albuquerque. I tried to cool down by heading towards the mountains--to no avail.
Brought the ST home and got on the Ultra and it was even hotter behind that full fairing. Gave up on those two and took a spin on my VStrom. Amazingly, it was still too hot to be comfortable. Unless you absolutely have to, I'm going to recommend you leave them parked and possibly ride in a car with the air turned on.
 
Our riding season is way too short so we don't complain about heat up here.
Taking the cage is not an option for me when the weather is hot.
 
2nd UPDATE

Well I had to go pick up a part this afternoon about 2:00 PM and with the heat here (San Gabrial Valley, CA) I figured I do another check.

When I fired up the bike the air temperature indicated was 110 degrees. Temperature from my thermometer was reading 118 degrees in the sun on the gas cap, mounted where it was before. This time I just velcro'd the external sensor to the battery cable in the opening at the battery below the panel. Once I got moving the bike temperature dropped and held at 102 degrees. Temperature at the gas cap remained at 118 degrees, I think being heated by the metal gas cap itself. The external sensor was running about 110 degrees while moving and would climb to about 112 - 115 degrees when stopped in traffic.

After strapping my part to the back of the bike I fired it up. The air temperature was now FLASHING 122 DEGREES . What do you think the bike was trying to tell me?

The trip back was almost a repeat of except as I got closer to work it cooled to 97 degrees. Temperature for the external sensor at the battery was running about 105 degrees.

It was warm on my feet, dress slip-ons instead of my Sidi's, but not what I would call unbareable. I was wearing my Olympia mesh, helment and gloves though. By the time I got back to the office front was dry but my back looked like it just came out of the washer, not dryer.

Unless I get some hotter temperatures I think I call an end to this test. I hope some of this information was a little enlightening.
 
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it would be very interesting to see you do this test back-to-back with an ST1100 as well. I keep hearing that the 13's are hotter than 11's, but have no way to truly know. I also don't know how much of that heat is radiant verses direct contact. That is, at 6'2" my shins bump up against the fairing on my ST1100. I've measured the temps there (using a digital temp gun) at up to 150 degrees! Having temp sensors on one's legs, then doing identical runs on a ST1100 followed by a ST1300 would be very interesting...
 
Here's the morning update.

I mounted the external sensor to the zipper cover at the bottom of the jacket. That puts it in the crotch/seat/tank area. Ambient air temperature was 75 - 77 degrees on the ride to work. Indicated temperature on the external sensor was running 2 - 5 degrees warmer than ambient air temperature. Less will moving on the freeway at 55 mph or faster, higher on surface streets stuck in traffic.

It's supposed to be over 100 degrees this after noon so I will report back with the results from the ride home.
 
v908 said:
it would be very interesting to see you do this test back-to-back with an ST1100 as well. I keep hearing that the 13's are hotter than 11's, but have no way to truly know. I also don't know how much of that heat is radiant verses direct contact. That is, at 6'2" my shins bump up against the fairing on my ST1100. I've measured the temps there (using a digital temp gun) at up to 150 degrees! Having temp sensors on one's legs, then doing identical runs on a ST1100 followed by a ST1300 would be very interesting...
Click to expand...

My 94 was cooler in the ankle area, but the left side of the tank (shelter cover) was so damn hot (ambient temps over 85) I had to hold my leg away from the tank. This was a common problem with ST1100's and was cured by some with insulation under the shelter cover on the left side.

Phil
 
I wonder if anybody on this forum has access to a wind tunnel (I know it seems like a long shot, but what the heck)... I would like to know about the air flow around/through the ST13. And especially how the air flows around my legs in the pocket formed by the backs of my legs and the front of the saddle bags... Hhmmmm... I may take the bags off and see how it feels... Anyway, a wind tunnel analysis would be GREAT! :D
:cool:
 
ChipSTer said:
I wonder if anybody on this forum has access to a wind tunnel (I know it seems like a long shot, but what the heck)... I would like to know about the air flow around/through the ST13. And especially how the air flows around my legs in the pocket formed by the backs of my legs and the front of the saddle bags... Hhmmmm... I may take the bags off and see how it feels... Anyway, a wind tunnel analysis would be GREAT! :D
:cool:
Click to expand...
You can simulate a wind tunnel by using a large fan (rental) and some tracer material i.e. smoke. Place the bike and rider on the center stand, then blow a small stream of tracer gently from the front of the fan, over the bike's front. Raise and lower the smoke to see the results of various parts of the air stream on the bike.

You won't be able to calculate the coefficient of drag but you will see where the eddies and turbulent air are located.

With sufficient fan force, I'd bet that one could see the wind-screen flexing side-to-side as it loads, then unloads air trapped between the screen and the black plastic of the "dash". I'd further bet that the oscillating release of trapped air is what some riders see when they speak of a "wobble", noticed when passing some trucks. Moving the screen outward with spacers should eliminate this problem, as should cross-bracing the top of the shield to remove the flex.

This is an interesting question. Anyone in SoCal want to do some investigation with me?

Marshal
 
Sorry for taking so long to get back on this. Friday's ride home seemed to be more of the same. By that I mean that the temperature in the crotch/seat/tank area was running about 5 degrees warmer than the air temperature itself. At one point it got to 7 degrees warmer in slow, crawl traffic.
 
I have the seat set on the highest position to accomodate my long legs. That means the space between the seat and the tank is widest. The heat gets rowdy after a while riding. I have solved it somewhat by rolling up a terry cloth towel and putting it between the seat and the tank while riding. I don't bother with it during short runs, but it sure helps on long rides. I even tried it wet, but it dries out quickly and gets hot before it dries.
 
how much heat

got my first real ride in today 240 miles in florida's 93-96 heat........put on a pair of thin socks and then wrapped my legs up to the calf in aluminum foil ....only half way around.........put on regular socks and riding shoes and was really surprised by the difference in the heat on my bottom legs.......and am thinking of lining the right fairing storage area with foil to cut down on heat......
 
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