Noticing heat after mirror deflectors

Joined
Nov 10, 2016
Messages
48
Location
South Central PA above the Mason Dixon line
Bike
2012 ST1300
I have read about all there is to read here about the heat issue. I finally noticed the heat yesterday on an extended ride. Nothing abnormal about about the seat or tank getting hots just shins and feet. We have had a rather cool spring but I have ridden in some warm (80s) with no notice of heat until yesterday.

I have a National Cycle V-Stream shield. The real change happened when I installed the mirror deflectors. The shield/deflectors were immediately noticeable even on short rides at lower speeds. At Hwy speeds the envelope just seemed to get bigger or at least stay the same.

Along with that pocket of protection I finally notice the heat on my lower legs. Should I get the lower fairing deflectors?
 

pumper316

SaTx Speed Demon!
Joined
Feb 22, 2017
Messages
121
Location
San Antonio, TX
Bike
'04 ST1300A
I have the mirror deflectors with Baker Air wings. The only time I've ever been bothered by the heat is in stop-n-go traffic. The Bakers do a great job of keeping the heat away from my legs.
 
Joined
Sep 22, 2015
Messages
1,282
Location
Wasaga Beach, Ont. Canada
Bike
'04 ST1300 Blue STar
I have the mirror deflectors only (did not want/need the lower deflectors),,, in combination with a Clearview GT medium. The mirror deflectors and CV screen work together to smooth out the airflow (less turbulent) over the rider. I also raked my CV a bit to accelerate airflow up the back of the screen,, which reduces back pressure to a low level. I typically look over the screen,, and get bugs on my helmet and visor,, and get some smearing on inside of the screen too. This is relevant to the heat issues, because you have to recognise that if you create a low pressure bubble in the drivers space,,, it will draw heated air into that bubble/zone via any available route. The ST13 does heat saturate on longer rides,,, making it more difficult to shed heat. There are many steps you can take to accomplish this,,, which are well documented in the many posts on the topic. Some will be right for your particular situation,,, and others will not be. Overall,,, I am happy with the upper wind deflectors,,, and so so with the CV windscreen. But generally,,, the combination is working well enough for me,,, Cat'
 

Dave.David

Rider
Joined
Dec 9, 2016
Messages
716
Location
SB California USA
Bike
05,ST1300-04VTX1800R
STOC #
8938
Thanks Catmandu2,
Even though there is little to no back pressure on me with the present setup there seems to be reduced flow behind the V-Steam windshield than before the mirror deflectors.
Are you wearing boots? Not wearing shoes I hope. Will make a difference of course.
 
Joined
Sep 4, 2013
Messages
8,115
Location
Cleveland
Bike
2010 ST1300
One of the nice features of the ST is the protection from the elements that the fairing and windscreen provide. The downside of course, is the heat buildup. Installing an aftermarket screen and the rubber deflector kit cuts down on (cooling) air flow compared to the OEM, bare bike. I never felt heat on my ST with the Calsci shield and delfectors on the slab. When I started aggressive riding w/ the ST crowd or BMW club guys then the heat kicked in. I believe Mark said that it takes around 15 hp to maintain highway speeds - that figure might have been for a car - and heat production really increases when we brake for corners and accelerate out of them, again and again.

No real solutions, though Cat's baker air wings might do the trick. I saw a friend's Wunderlicht air deflectors and made a couple to experiment with on my bike. I clipped them to the windshield, and then saw this knockoff on ebay LINKY . Its too soon to know how they work. If the ad is expired search for 'motorcycle wind deflector'. The Wunderlicht item sold for around $160, and they have quite a few variations. The ebay k.o.'s are much much cheaper.
 
Joined
Sep 22, 2015
Messages
1,282
Location
Wasaga Beach, Ont. Canada
Bike
'04 ST1300 Blue STar
Not my Baker wings,,, those belong to Thumper. I did not want any lower deflectors,, as most of my heat build up was cured by removing my inner cowls. It was easily done,, and actually I had all my tupperware off for a valve shim inspection, and so I just left the inner cowls out for a test trial. Cold air dilution was so effective that I never re-installed them. Adding any lower deflectors (for me) was not needed,, and would have only increased drag, turbulence and back (negative) pressure in the driver zone. The upper deflectors I wanted to smooth out the airflow,, which they did for both the oem screen and the Clearview. Both screens I used raked,, which increases backside airflow (diluting heat),, and reduced back pressure (which also reduces heat being drawn into the drivers zone). Deflectors also increase noise,, which for some may be a consideration. I have a 1000 mile rally coming up this weekend,,, so I will report my findings on Monday,,, Cat'

One of the nice features of the ST is the protection from the elements that the fairing and windscreen provide. The downside of course, is the heat buildup. Installing an aftermarket screen and the rubber deflector kit cuts down on (cooling) air flow compared to the OEM, bare bike. I never felt heat on my ST with the Calsci shield and delfectors on the slab. When I started aggressive riding w/ the ST crowd or BMW club guys then the heat kicked in. I believe Mark said that it takes around 15 hp to maintain highway speeds - that figure might have been for a car - and heat production really increases when we brake for corners and accelerate out of them, again and again.

No real solutions, though Cat's baker air wings might do the trick. I saw a friend's Wunderlicht air deflectors and made a couple to experiment with on my bike. I clipped them to the windshield, and then saw this knockoff on ebay LINKY . Its too soon to know how they work. If the ad is expired search for 'motorcycle wind deflector'. The Wunderlicht item sold for around $160, and they have quite a few variations. The ebay k.o.'s are much much cheaper.
 
Last edited:
OP
OP
Joined
Nov 10, 2016
Messages
48
Location
South Central PA above the Mason Dixon line
Bike
2012 ST1300
I just tried using the V-Steam shield in the upper position and it seems to have worked. I notice alot more air on the backside of the shield and smoother air flow at side and behind me. At best of all if I move my feet to outer edge of the pegs I can feel cool air flow on my inner sides of my feet. 90% of the time I use boots but I did not today just to see if any difference could be felt. Thanks all for prompting me to think outside the box. I love this bike!
 
Joined
Mar 31, 2016
Messages
256
Location
Grand Rapids, Mn
Bike
2004 ST1300
It doesn't get "hot" too often in MN, but when my legs/feet get uncomfortably warm, I find it helps a lot to tip my boot toes down below the pegs. Even a few inches scoops quite a bit of cool(er) air up past my legs and delivers some substantial relief.
 
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