GL1800Riders Forums banner

1 - 16 of 16 Posts

·
Registered
Joined
·
4,310 Posts
Discussion Starter #1
I have noticed that the 200/55 rear tire on the Wing gets hotter than other rear tires (I had on Wings or other bikes) even during cool days.

Today is 80 deg. and I went on a 30 mi. ride. the PSI on the rear went up to 48 the front to 42.5 tested immediately upon getting off the bike.

I had the rear at 42 and the front at 39.5 last checked cold.
The book calls for 36/41. I think I better start abiding by the book and watch the tires carefully if I ever cross that dreadful desert--which right now it don't seem so bad, as it typically does.

The tires are pretty damn hot for a little ride like this. These tires really seem to heat up for some reason.

Tires are Dunlop 423/s front and back. off the show room, 4,888 miles on them

Anecdotal: Once crossing the desert a rear tire for a GT got up to 56psi on me...that was doing 90 in really hot temp. The tire was so hot you couldn't eve touch it. I always wondered how close I was to a blow out. I done some research on this but to no avail.

How would one know the max tire pressure/temp at which one would want to ride a Wing?
 

·
Registered
Joined
·
788 Posts
The tires are designed to get hot and have the pressure increases. That's why they tell you to check tire pressures when cold.
I have put at least 100,000 miles on my Goldwings and I live in the desert. I have never had an issue with delamination or anything else on my Goldwings. I am also a fairly aggressive rider and have pulled a loaded trailer for several thousand miles.
I think you are probably worrying about nothing.
 

·
Registered
Joined
·
1,879 Posts
wider tire = ,more surface area on the road at any given time = more friction potential = more heat buildup potential = hotter tire on the rear than front. Now the obvious and that defined by basic physics have been pointed out, I have a couple other potential causes. A hot engine is directly in front of the rear tire potentially causing it to "live" in a slightly hotter environment than the front tire, and if the engine is not enough, there are two hot mufflers going right past it helping to increase the surrounding air temperature the rear tire "lives" in. I have an added TPMS with internal sensors on my Suzuki M50, and that rear tire REALLY gets hotter with a steeper climb than the front. The only time I have seen a hotter front tire was with the bike sitting in the parking lot at work in the hot summer sun with the rear covered up by soft saddle bags.
 

·
Registered
Joined
·
4,310 Posts
Discussion Starter #4
Appreciate the comments!

The question that begs itself is What is the safe temperature range of our rear tire?

Most folks suggest to put it at recommended PSI and let it be. Well that is fine and dandy, but I would still like to know what is the temp red-line.

I read of a guy in Australia boasting of riding in 140 degree weather. Whether that was true or not, it would be interesting, if not useful, to find out what is the danger range temp on a bike tire.

My TPM measures tire temp as well as pressure.
 

·
Registered
Joined
·
1,055 Posts
I'd also like to know the max temp a tire would be considered safe. Having said that I ride and 02 with E-4s, fully loaded and often pulling a trailer and find tire pressures rising 8-10 psi regularly and haven't incurred any issues (I start at cold temp pressures of 41 & 42 psi). High heat road temps surely take a tola on the tread though; I routinely ride in 100+ temps (as high as 125 at times) and one time I did note faster tread wear. Perhaps slowing down and avoiding high stress, high speed long cornering (desert twisties) might be advisable.
 

·
Registered
Joined
·
1,879 Posts
The TPMS I put on my M50 and Tailwind trailer has a high temperature warning set to 212 degrees by default. Not knowing the answer to "what is too hot and should be warned?" I left it as default.
 

·
Registered
Joined
·
4,310 Posts
Discussion Starter #7
The TPMS I put on my M50 and Tailwind trailer has a high temperature warning set to 212 degrees by default. Not knowing the answer to "what is too hot and should be warned?" I left it as default.
...just in passing: while I was doing a lot of research on this a while back I came across some lit. that claimed the racing tires limits were about 120 F...now don't quote me on this cause I am not sure about the source I vaguely recall. But I would say off the top of my head that 212 deg F be awfully hot for a rubber tire.

I have been extremely frustrated about this inquiry cause no one seems to have data on this issue. Many opinions, but no data.
 

·
Vendor
Joined
·
21,574 Posts
Many factors influence tire temp, including carcass construction and tire compound. Softer tire compounds run hotter than harder compounds. I think the compound on the Dunlop 423s is a little on the soft side, so this could account for them running a little hotter. Load, speed, and road type also impact running temp. I've seen internal rear tire temps as high as 180 degrees on the previous generation Wing when I had a TPMS that would read temp. Higher temps will cause the tire to wear out faster. But I don't think you'll ever reach the danger point of blowing out a tire from heat unless it has a defect, the tire manufactures do pretty thorough endurance testing.

If you're worried about the rising air pressure in your tires due to heat, there are a couple things you can do to reduce it. Air pressure rises because of water vapor, so if you use dryer air to fill them, the pressure won't rise as much as the tires heat up. You can do this by putting a desiccant snake on the air hose you fill them with to try to trap any moisture in the air before it gets into the tire. Or you could switch to nitrogen, because one of the main benifets of nitrogen is that it has zero water vapor in it, thus your pressures will stay more constant over a wider range of temps. There are some claims that nitrogen filled tires run cooler because of the reduction in water vapor in them, but I can't say for sure if this really is true. It is true that the pressure won't rise as much, because the expansion of the water vapor is the main cause of the rise in pressure.
 

·
Registered
Joined
·
1,879 Posts
Tire temp limits of 120 F? I should have torn apart my rear M50 tire several times since I had the TPMS.... I have hit 140 on the rear on a longer freeway rides on a 90-100 degree summer day I have often had over 110F on the rear. 120C is 248F, so maybe that was C instead of F? 120F is just way too low to be a dangerous tempurature.
 

·
Registered
Joined
·
4,310 Posts
Discussion Starter #10
Thanks Fred
Thanks DDL

This puts me at peace a little more. I cross that desert between Diego and TX just about every Summer and I always wondered...
 

·
Registered
Joined
·
685 Posts
When asphalt gets hot enough to fry eggs on its obvious tire temps are going up accordingly. 150*F and higher wouldn't surprise me much and can probably figure tire temps on racetrack bikes get higher yet. Front will always be cooler. It is generally narrower, carries less weight, is leading into the wind, not behind the hot engine/exhaust/etc. Other than accelerate wear, I don't think there is much to worry about tire temp. I'm sure the tire manufacturer has tested them beyond what most of us ever see.
 

·
Registered
Joined
·
4,823 Posts
That could explain why DDL mentioned that a temp sensor warning was set at 212F, the boiling point of water. There is always water in compressed air. If that water were to vaporize, the sudden pressure increase could be catastrophic. Of course the pressure inside the tire will raise the boiling point of the water droplets making 212 a pretty good warning point.
The pavement surface can get up to 140-150 degrees in summer...add to that an underinflated, loaded tire running at 70-80 mph right next to the exhausts and rear tire temp could easily get into the high 100s.
I stopped for gas once and a guy had just pulled in in front of me. Ambient temperature was about 104F. He was in a truck pulling a trailer. When I walked by his trailer I smelled smoke. One of his trailer tires was obviously low on pressure and was smoking it was so hot...but it had not yet blown! I'm guessing that tire was hotter than 212.

(This post was meant to quote Fred H. but somehow I failed to get the quote to take.)
 

·
Registered
Joined
·
1,236 Posts
Sometimes, I think that too much information is a bad thing. Most of us rode for years without knowing what our tire temperatures were, and didn't give it a second thought. Now that we have the information, it just gives us another factor to (unnecessarily?) think about.
 

·
Vendor
Joined
·
21,574 Posts
Here is some more food for thought.

The main cause of heat in a tire is from the carcass flexing. This causes frictional heat within the belts that makes the whole tire heat up. As the air in the tire gets hot and expands, it increases the tire pressure. As tire pressure increases, the sidewalls are less able to flex. So maybe it is a good thing that the pressure in your tire increases with tire temp, since it makes the tire firmer which help prevent even more heat build up.
 

·
Registered
Joined
·
788 Posts
Here is some more food for thought.

The main cause of heat in a tire is from the carcass flexing. This causes frictional heat within the belts that makes the whole tire heat up. As the air in the tire gets hot and expands, it increases the tire pressure. As tire pressure increases, the sidewalls are less able to flex. So maybe it is a good thing that the pressure in your tire increases with tire temp, since it makes the tire firmer which help prevent even more heat build up.
I agree Fred. From what I have always heard is that tire failure is usually associated with under inflation. That's why truckers go around hitting their tires with a steel bar to check for low pressures or flats.
 

·
Vendor
Joined
·
21,574 Posts
I agree Fred. From what I have always heard is that tire failure is usually associated with under inflation. That's why truckers go around hitting their tires with a steel bar to check for low pressures or flats.
Yes, its a well known fact that underinflation causes tire failures due to overheating.
 
1 - 16 of 16 Posts
Top