If it is below 40 deg F, should I have the middle cowl open or closed
- Thread starter kurtfriedrich
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daddysbike
Well-known member
Hot weather = open vents, keeps heat off legs.
Colder weather = close vents.
I rode my '07 for the first couple months with the vents closed (didn't think about 'em).
I then rode with a couple other FJR riders and mentioned that I like my FJR but like all the other fully faired bikes I owned it blows heat on my legs (though not as hot as ST1300). One of the other riders said to open the vents which I did and was amazed that I could not feel any heat blowing on legs and have ridden the last 10,000 miles like that.
Steve
Colder weather = close vents.
I rode my '07 for the first couple months with the vents closed (didn't think about 'em).
I then rode with a couple other FJR riders and mentioned that I like my FJR but like all the other fully faired bikes I owned it blows heat on my legs (though not as hot as ST1300). One of the other riders said to open the vents which I did and was amazed that I could not feel any heat blowing on legs and have ridden the last 10,000 miles like that.
Steve
JohnB
Well-known member
This is exactly the opposite of what Yamaha claims. They say:
Vent open = warmer for the rider because cool air is deflected away from the rider.
Vent closed = cooler for the rider because cool air is NOT deflected away from the rider.
Pie is running a close second. Mmmm pie...
Lake Powell
Well-known member
My unofficial, totally sober, take on this is with the panels away from the frame my legs were a little warmer. Or maybe not as cold.
It was 55F today.
It was 55F today.
Midlifefjr
Well-known member
Long winter, very long winter. Groundhog not see shadow.
EXPDSGT
Well-known member
Here's my take on the science, my opinion, and an EASY way to test on your own.
My take on the science:
I think that motorcyclists and skydivers are very keenly aware of what Wind Chill Factor is all about. If I'm in 30F air that isn't moving it doesn't feel all that cold - I could easily survive with a light jacket and light gloves. But bust out a fan and blow that same 30F air at me at 30MPH and suddenly I'll be wanting to put on a thicker layer of insulation, preferably something wind-resistant. The colder moving air pulls heat from a warmer object faster than still air does.
Along the same lines, a convection oven will heat up food way faster than a regular oven since the warmer moving air transfers heat into a cooler object faster than the still air of a standard oven does.
When the air rushes past the FJR's radiator and engine it picks up heat, and then that heated air gets directed somewhere. If you have the side vents closed (in the inward position) then air that's been heated is hitting the legs moreso than if the vents were in the open (outward) position.
I think that we all can understand the above. The point of contention is whether having the air that's been heated blowing on the shins is preferable to deflecting it away (somewhat) from the shins.
My body is supposed to be running at a constant 98.6F. However, air temps that high feel hot to me since my metabolism requires that I be able to release heat from my body at all times. So I prefer the feeling of air that's in the mid to lower 70's while at rest, or the mid to upper 70's at higher wind speeds. We're all different so your comfort range may be different from mine. Air warmer than that feels warm since it's not wicking heat from my body as quickly as I'd like. And at 99F and up the air is actually warmer than I am, so the air tries to put warmth into me - yuck! At that point I'm surviving due to the cooling effects of perspiration.
I don't know how much the air that comes off the engine heats the air. For the purposes of this discussion that would be helpful to know (anyone have a thermometer that they can strap to their leg?). But if I had to guess I'd say that when the FJR is moving the air that goes out the vents has been raised in temp somewhere between 5F and 15F, depending on speed. So, if it's 40F outside and the air gets raised 5F to 15F, then the air coming out the vents is around 45F to 55F, and that's still a might chilly for my tastes. If it's 95F outside and it gets raised 5F to 15F then the air coming out of there is higher than my core temp, and so therefore it's trying hard to put heat into my body (like the convection oven).
My opinions about the vents:
1) If the temp is above about 80F degrees or so I definitely prefer them in the outboard position. I don't want the hot air hitting my shins.
2) If the temp is below about 60F degrees or so I definitely prefer them in the outboard position. I don't want the cold air hitting my shins.
3) If the temp is between about 60F and 80F I kinda don't care so I leave them in the outboard position since it's less work.
So, mine are in the outboard (open) position at all times. (In spite of those fugly exposed screw-holes.)
The EASY way to test on your own:
One problem with testing how something feels (or sounds, or tastes, or practically anything to do with our senses) is reproducibility. If there's too much time between 2 tests we tend to not be as able to accurately gauge the difference between 2 samples (some people are good at it (e.g. people with perfect pitch), but they're outside the bell curve). If someone replaced the light bulb in your garage with one that was 50 lumens brighter or dimmer while you were on vacation, would you notice? Almost certainly not, even if they told. But if you switched back and forth between the 2 lights in a very short period of time (e.g. less than a few seconds) then you almost certainly could tell the difference. The same is true for temps. If you let a few minutes go by, your perception of a previous temperature becomes less reliable to compare a new sample against. (I won't even go into the whole "power of suggestion" thing, which can throw some amazing monkey wrenches into experiments in which people are the sensors.)
It's been suggested to have one side vent be out and one side in. However, using 2 different limbs to measure a temperature isn't necessarily very reliable. That's easily testable: Filled a pan with 80F water and set it aside. Fill 2 other pans with water, one icy cold (full of chunks of ice) and the other fairly hot (105F to 110F). Put one hand into each of those extremes and let them sit there for a minute and then put both of them into the 80F water. Each hand will report to your brain a different story - the hand from the cold water will say that it's been put into very warm water, whereas the hand from the hot water will report that it's in rather cool water. Same water but measured by different hands with different experiences, yields different feelings.
What you CAN do is this (and I've suggested this same thing in several posts on the subject, though not with as much background detail): Put the vents in the outward (open) position. Get the engine up to operating temps by riding around for at least 10 minutes or so. Then get up to the speed at which you want to test. Then test by extending your legs out into the air stream for a minute or so. It's the same air, blowing past the same radiator and engine, but there's far less time for your legs to forget the previous test. If it's 100F outside and your legs tell you that having that 100F air that's been heated by the engine feels cooler to you then by all means stop and move the vents inward. My legs tell me that the air is trying to put heat into them, so I leave them in the outward position on hot days.
When it's 40F outside, it feels *to me* that the engine doesn't heat up the air enough for it to be comfortable, so I leave the vents out on those days as well. On those days between the extremes it kinda doesn't matter, so why go through the hassle of moving.
Of course, your milage (er... senses) may vary, and I can think of a few other minor issues with the experiment, but I still think that it's basically a good valid test. If you notice a difference then cool - act on it. If you don't then by all means leave the vents closed - I think it looks better that way (again, your senses may vary on that point as well)! I put forth the above explanations and tests that you can do yourself so that you can at least make an informed decision and test for yourself.
Bunsen
What ??????????????????????????????
Joe2Lmaker
Well-known member
JohnB
Well-known member
Sorry, Doctor, but this link proves nothing since it doesn't indicate which way is warmer and which is cooler. My conversation with a Yamaha "product specialist" indicated that "out" is warmer because it deflects cool air away and "in" is cooler because it doesn't.
Personally, I leave mine in the closed ("in") position and have forgotten about it UNTIL NOW.
Captain B
Well-known member
Best answer yet! One vote.If you look carefully at those "doors", they do not allow any engine compartment air to escape between the open door and the frame, and onto your legs in either position. Their only purpose in the outward position is to deflect air (which is a combination of engine hot air and outside air) further away from the bike and your legs.
Some say, they are warmer in the open position because they reduce the total air blowing by on your legs.
Some say they are warmer in the closed position because you get more engine warm air on your legs.
My independent testing revealed the following:
The bike was riden with the deflectors closed on a very hot day, and my legs were hot. I then opened the deflectors and rode and my legs got even hotter. To make sure the test was valid I then closed the deflectors and rode some more and my legs got even hotter still! Confused at this point I then opened the deflectors and rode again and by now my legs were burning up to the point were I was unable to ride any further!! I stopped the bike, let it cool completely and closed the side deflectors and have never moved then since. The testing has concluded that each time you move them you will get hotter no matter which way you go!
Be carefull out there.
I gotta agree that it is best to keep those fugly screw holes covered. So I voted for Pie.
John
John
Captain B
Well-known member
OK, so let's - for the sake of arguement (this is the FJR Forum after all) - say that it does not make any difference - heat wise - whether they are open or closed. That the difference, if any, is in the mind of the befuddled. But, if the cowls are in the open position are you better protected in a crash? That is, is there sufficient support behind them to keep them in place and thus provide some added protection to legs?
odot
CC member # 17,----- DUP member # 7, mensa club m
DIEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEE THREAD, DIIIIIIIIIIIIIIIIIIEEEEEEEEEEEEEEEEEEEEEE!!!!!!!!!!!!!!!!!!!!!!!!!!!!
DrBunsen
Well-known member
At the very least it's clear that there's some confusing information on the issue even from Yamaha. We'd had pretty much this discussion 14 months ago and several of us thought that it'd been settled, but it still pops up.
Here's a link to a post where someone in the forum got the same information you did from a Yamaha tech: Clicky
Here's a link to a later post where someone checked back again to see if they might've made a mistake in the earlier advisement, and this 2nd tech reversed the advisement, stating that in (closed) blows more heated air on the rider's legs, and out (open) deflects it away: Clicky
But, really, the cool thing is that we can experiment and see what we like. Hell - I *prefer* the look of how the vents look in the closed position. So I applaud anyone who wants to leave them closed, regardless of the reason. But my feelings and experimentation on the subject, and my interpretation of this page is that closed means warmed air blows on you, and open deflects it away. You feel otherwise, and, well... OK. If everyone felt the same way about everything then everyone would be Southerners.
Bunsen
MrTwisty
Well-known member
I must admit, I feel like a dumb arse. I don't even know where the middle cowl is, nor how to adjust it. Therefore, I vote for pie...and leave poor Britney out of this, she has enough problems. :dribble:
Like others, I had completely forgotten about that adjustable cowl until this thread/poll was started. In the last week I've had 2 morning commutes with temps right at freezing. The first morning I had the cowl closed and my legs were cold. This morning I had the cowls open and my legs were noticeably warmer.
Because my built in leg thermometers have been calibrated to standards traceable to NIST, I can definitively state that cowls open are warmer. Dont' try to argue; I'm right and you're wrong :excl: :devilsmiley:
Because my built in leg thermometers have been calibrated to standards traceable to NIST, I can definitively state that cowls open are warmer. Dont' try to argue; I'm right and you're wrong :excl: :devilsmiley:
kurtfriedrich
Well-known member
I wonder if we are all adjusting them "out" the same amount. What is the total travel from full in to full out?
Kurt
FuzzyRider
esolc oot m'I siht dear nac uoy fI
I opened the cowls on my bike last week. Why? Well, because I thought it might be warmer that way. But, after careful consideration I'm decided that my legs must not be sensitive enough because I can't really tell a difference. If anything, I thought it might be a little cooler but not enough so to be sure.
Anyways, I really do like pie.
Anyways, I really do like pie.
