Cooking my legs on an RT

I just had my 83 RT out for a highway ride of a few miles. The heat coming back at my lower legs was equivalent to running a nice 150,000 btu torpedo heater at full blast a few inches from both legs. I have searched the forum but found nothing except that K100s seem to be pretty bad also. Not much help. I know the airheads can be called "heaters" but this is ridiculous. The engine is running fine, that is not the problem. Am I the only one to notice this design flaw? How in the world do people travel all day on these things? Your legs are just being cooked. I think I will look pretty dumb with hand made heat shields strapped to the front of my legs, or having to stuff newspapers down my pants every time I want to go for a ride. Any solution to this very real, and very irritating problem? Does a Goldwing do this? An ST 1300? Oilhead? F bike? Or is it just the.... "airheads"?

You will feel some heat on any motorcycle. It is a matter of how much you are able to tolerate in order to have the bike you want.

Maybe I have been numbed after all the years of riding an airhead in Texas. I feel some heat but I would rather put up with the airhead than many other bikes. The K100 I had for a while was like sitting on an oven. I couldn't wait to get off that bike. The seat, fuel tank, side covers, all got very hot, especially when the fan kicked in.

At least on an airhead the heat is more or less confined to the lower legs. I once took off the lowers, thinking this would make things more comfortable in the summer. It made things worse. The heat was directed upward without the lowers.

I have ridden the ST1300 on a warm (80 degree) day. I could feel heat and I could only imagine what it would be like in the middle of the summer when it would be 20 degrees hotter. One Harley rider I met recently said that the rear cylinder would cook his leg. He said it was intolerable and was selling it for that reason.

Are you sure that everything is in proper order? The engine is not running abnormally hot for some reason? If there is nothing wrong then the heat is something that comes with the territory.

Heat yes, 18k degrees, NO!

I ride an 84 R100RT, rode in very hot weather. For long distances and not once had my legs roast, some heat yes. Road both in town and on the road no real discomfort. (I guess you were not wearing shorts, say it ain't so for a Beemer rider.) If for some reason your pants were wet you could of gotten extra heat transfer. I once washed my bike and went for a ride on a very hot day and noticed more heat till they dried. I sometimes were bike jeans, but on longer trips it is always riding pants.

I think you must be getting extra hot air from someplace.

I rode both with the lowers off and on. Never once did I experience that much heat, unless I was at a traffic stop then the heat was all over during construction (just turned the bike off before it melted). I know this weather we are having in the Mid West is unusually hot and humid, that is a contributing factor.

Stop wearing shorts when you ride. Long pants for safety. That's my guess.

You've been numbed by Texas HEAT for sure...

No maybe about it. Me too. 103 today north of Dallas ~ again

fracture said:

You will feel some heat on any motorcycle....
Maybe I have been numbed after all the years of riding an airhead in Texas. I feel some heat but I would rather put up with the airhead than many other bikes. The K100 I had for a while was like sitting on an oven. I couldn't wait to get off that bike. The seat, fuel tank, side covers, all got very hot, especially when the fan kicked in.

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My friends who own K's cuss its heat in summer but no one complains in the winter. With that style of injection what fuel is not burned is returned to the tank bringing heat from the engine with it - which on a long trip can become uncomfortable I expect.

At least on an airhead the heat is more or less confined to the lower legs.

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The all-aluminum top ends cool more effectively than the older iron barrel bikes of the 70's. I noticed that right away when I got an 81 and later an 83 with full fairing. Real foot-warmers~! Some of the most miserable heat we deal with riding bikes comes from the road itself.

Oh, come on. No, I'm not wearing shorts. If I had been the hair on my legs would have been burned off. Am I reading this stuff correctly? Keep my clothes in an air conditioned room before I ride? Wear extra-extra protective pants? Learn to tolerate the extreme heat because the bike is so special? Guys, look down from the airhead seat. Your legs are positioned directly behind two very hot cylinders with fins put on them to suck the heat our of the engine. The air flow goes right across them into your legs. This isn't my imagination. It's hot. Would any of you drive a car where the heater was stuck on high all summer? I thought not. I can see that everyone knows this is a problem. And so far I haven't seen a realistic solution. Maybe I should buy bags of ice and tie them to my legs. I don't know about anyone else, but I need a bike I can ride in comfort, any weather. I don't figure I should have to suffer with my legs being bathed in 200 degree air just so that my motorcycle can be comfortably cool.

jconway607 said:

Oh, come on. No, I'm not wearing shorts. If I had been the hair on my legs would have been burned off. Am I reading this stuff correctly? Keep my clothes in an air conditioned room before I ride? Wear extra-extra protective pants? Learn to tolerate the extreme heat because the bike is so special? Guys, look down from the airhead seat. Your legs are positioned directly behind two very hot cylinders with fins put on them to suck the heat our of the engine. The air flow goes right across them into your legs. This isn't my imagination. It's hot. Would any of you drive a car where the heater was stuck on high all summer? I thought not. I can see that everyone knows this is a problem. And so far I haven't seen a realistic solution. Maybe I should buy bags of ice and tie them to my legs. I don't know about anyone else, but I need a bike I can ride in comfort, any weather. I don't figure I should have to suffer with my legs being bathed in 200 degree air just so that my motorcycle can be comfortably cool.

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No, I do not consider an airhead to be a special bike. I tolerate its quirks because it has advantages I value, just as a sport bike rider tolerates what I consider to be a painful riding position because he likes the performance. Yes, heat is a problem for some. It is not a trivial complaint. Bike riding should be enjoyable, not an exercise in pain endurance.

The guys are right about wearing proper gear. I once tried riding with shorts and no socks to see if that would help. Big mistake. My ankles and calves were burning in short order. With socks, jeans, and proper footwear the heat is not that much of a problem for me. I have ridden bikes that were much more uncomfortable.

The best fully faired bike I have been on so far was a Triumph Trophy 900. The heat management was very good. Heat was ducted away to the sides and never reached the rider. Triumph is rumored to introduce a new 1200 Trophy soon. Maybe the heat management on this one will be just as good.

Although you say it is running fine, can you make some checks to determine if the engine is running abnormally hot for some reason? Maybe install one of those oil temp dipsticks. It is not the most accurate instrument but it may point to a problem. Also, is your passive air injection system still operating? This may cause more heat to be generated in the exhaust and thus you may feel more heat because of it. It may be a small difference but every little bit helps.

I assume your bike has an oil cooler and that it is functioning? The thermostat may be stuck. After a few miles on the freeway on a summer day the cooler should be hot to the touch.

jconway607 said:

I just had my 83 RT out for a highway ride of a few miles. The heat coming back at my lower legs was equivalent to running a nice 150,000 btu torpedo heater at full blast a few inches from both legs. I have searched the forum but found nothing except that K100s seem to be pretty bad also. Not much help. I know the airheads can be called "heaters" but this is ridiculous. The engine is running fine, that is not the problem. Am I the only one to notice this design flaw? How in the world do people travel all day on these things? Your legs are just being cooked. I think I will look pretty dumb with hand made heat shields strapped to the front of my legs, or having to stuff newspapers down my pants every time I want to go for a ride. Any solution to this very real, and very irritating problem? Does a Goldwing do this? An ST 1300? Oilhead? F bike? Or is it just the.... "airheads"?

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I agree with you, it seems to me to be more to do with humidity than temperature. When we lived in West Texas we rode all day long at 100+ temperatures with no problem. Once back in St. Louis it feels like we are going to cook, not fun at all which is why the RS sits on hot days and I ride my Triumph. When the humidity is near 100 percent no amount of air, even with the lowers off, will cool you.

Wayne

jconway607 said:

I just had my 83 RT out for a highway ride of a few miles. The heat coming back at my lower legs was equivalent to running a nice 150,000 btu torpedo heater at full blast a few inches from both legs...Am I the only one to notice this design flaw?

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Design flaw? I guess you would be the very first one to call it that...

How in the world do people travel all day on these things?

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I sometimes hook my heels over the passenger pegs to get my feet away from the cylinders and farther away from the exhaust pipes and heat radiating off the road.

It's not all that bad, but there is more heat than a nekkid bike. I cut my lowers before painting to allow more flow. There is still heat, but the flow pulls it away much quicker than the stocker lowers.

Are your headers more bluish than darkish/black? Any chance you are still running with the emissions gear or leaner than you may realize? If you do still have the emissions gear, Bob's BMW used to sell a kit for about $12 to remove it and plug it up (assuming your state allows for that).

I've thought about dremelling a 2 or 3 horizontal slots about 50-70mm right at the curved surface corner but haven't felt the need--and I live in HOTlanta now.

Here's a picture prior, if you can make out the lower cuts to the back side. That was in April, on a 2000 mile trip from ATL to Wash/Balt and surround, not the coolest. That backside of the lowers has been completely removed both above and below the cylinder, to it gets better airflow. More important to me, because its not a REAL R100RT, I made it one, but skipped the oil-cooler. Not sure it'd be worth the expense.

ATGATT gets hot, just keep moving.

Design flaw? I guess you would be the very first one to call it that...

When you are roasting your extremities on an open air vehicle meant for warm weather use, I don't know how else you can phrase it so as not to hurt BMW's engineering staff's delicate feelings.
I have always had the highest regard for BMW , but I am beginning to see some chinks in the armor. No, my bike doesn't have an oil cooler. Sounds like it should, though. I don't believe BMW put them on all airheads out of the factory. Why not, if they needed it? Yes, I have all the emissions stuff. Stock bike, just like BMW designed it. I"m hearing that is another BMW engineered problem making it run hot. Fairing lowers are original. I guess they need some redesigning also to work better, although they probably won't ever be as good as the Triumph set up from what is said here.

A lot of people on this site seem to own a fleet of bikes. I gather this is so they can check the temperature, rain forecast, etc and leisurely select the best bike for the job that day. Maybe I'm just not cut out to be an airhead owner, as I don't want/can't afford to own three or four motorcycles with attending license, insurance fees, storage costs, maintenance costs, etc. One is enough for me. One good, practical, comfortable one.

Actually there are a number folks who own an airhead as their only bike and I suspect you may have hit a bit of a nerve using the term "Design flaw" which caused some to react as they did to this.

As for being unbearably hot, I guess that is pretty subjective but not something one normally associates with airheads esp. in regards to heating of your legs while moving. I've ridden other bikes/brands that can be much worse than an airhead, (other than being stuck in traffic where the heat rising off the engine can get quite noticeable). So maybe there could be a cooling issue with your bike since this in not a normal occurrence on an airhead. In fact they should stay quite cool (in comparison to other air cooled designs) because of the way the jugs are in the air stream, so rather than being a flaw it was specifically chosen to help keep the engine cool.

I'd check this out, or have it checked out or try to get with other airhead owners and have them look it over. This really should not be a major problem and certainly shouldn't be "cooking" your legs.

RM

you need two bikes: a naked airhead for summer and a faired one for winter, spring and fall. That would be ideal. I can ride my unfaired airhead with only shorts on (in the neighborhood for short errands) and no heat on the shins. Modern armored pants will ease the bake on the faired bikes.

jconway607 said:

When you are roasting your extremities on an open air vehicle meant for warm weather use, I don't know how else you can phrase it so as not to hurt BMW's engineering staff's delicate feelings.

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Guess you're not familiar enough with BMWs to realize this is a product of the 1981 switch to Nikasil cylinders. Perhaps you'd do better with one of the older iron-cylinder models, where all the heat is retained in the engine oil.

With my '84s, it's simply a formality to pull the dipstick to check oil level--with my previous iron bikes (I call them farm equipment) that would be problematic for sure.

And, of course, it was Nikasil that made the G/S possible.

Advice above is correct--wear the right clothing and put your feet on the passenger pegs.

lkchris said:

Guess you're not familiar enough with BMWs to realize this is a product of the 1981 switch to Nikasil cylinders. Perhaps you'd do better with one of the older iron-cylinder models, where all the heat is retained in the engine oil.

With my '84s, it's simply a formality to pull the dipstick to check oil level--with my previous iron bikes (I call them farm equipment) that would be problematic for sure.

And, of course, it was Nikasil that made the G/S possible.

Advice above is correct--wear the right clothing and put your feet on the passenger pegs.

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What does this have to do the the excess heat coming off the cylinder onto my legs? Actually, I think I am mighty familiar with BMWs. I've just spent two years completely rebuilding mine. Right down to the two little rubber O rings on the brake shaft. So your point is that by switching to Nikasil cylinders they solved one problem and created another? What does ease of checking the oil level, or the birth of the GS have do to with this discussion? Your final point is the best one. Put my feet on the passenger pegs. I guess I missed that directive in the Owners Handbook. Good idea. Right leg nice and far from the brake pedal for safety. And I guess the passenger (yes, rather oddly, I do demand that my bikes be able to carry passengers) kind of shoot her legs out into space for the trip. Yes, that will work. Problem solved.

I don't think there is anything wrong with your bike. It is 1980s technology. Here, in the 201X's, it still exists. FJRs were known to be hot, as well the Concours in earlier years, and I know my friend's F800ST is hot only on one leg! My R12RT is darn good with heat, but on a hot day, the heat from the oil cooler will rise at the handlebars and it's very warm.

So I guess what I'm saying is that your bike is likely "fine". Handling heat on hot days has been a struggle for motorcycle manufacturers for I guess as long as they've been made. Boxers especially since the jugs are right there by your legs.

If you can't handle the heat, I think you are stuck looking for a different machine. And liquid cooling may not be the answer (reference to my friend's F800). My R12RT handles the heat flow away from my body about as well as any bike I've owned or ridden.

Finally, I think you posted here to find an answer to your 'problem' and I don't think there is one. Those heat shields you mention may be the answer!

You have not experienced heat till you have rode a K1100LT in July. HOT!!!!!

kgadley01 said:

You have not experienced heat till you have rode a K1100LT in July. HOT!!!!!

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Agree, especially in Saint LouisGlad when I wrecked that bike. Got back to airheads.

Wayne

jconway607,
I have an '88 R100 RT. The first year I had the bike I rode around without the lowers. I noticed when I put the lowers back on the heat off the cylinders was directed more around my legs. I didn't think it was that bad unless it was really hot. I think it's a nature of the beast with regards to the RS/RT's. I would try removing the lowers and see if that helps. Unfortunately, these bikes are not perfect--especially by today's standards. Granted there are bikes out there with worse heat issues and others with less of an issue. I hope you can find a good work around for this issue.