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Working with heat transfer. Something I observed is bikes with crotch coolers. Interesting people install them and comment it helps keep your leg and body cooler. Cylinder still create same amount of heat so where did heat go......... It's in the cylinder. Crotch cooler slowes air flow therefore heat transfer. Remember rear cylinder air. Temp already raised by front cylinder therefore slowed transfer to 2nd. Cylinder. Newer cylinder deactivation only occurs at low air flow or idle.
 

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Bought a Captain Itch crotch cooler and it sits on my parts shelf.
Up here in the great white north its slow cooked prairie oysters unlike you southern boys in AZ for example, flash fried.
So going to one day gut the Cat, no rush. Keeps them warm on a morning like today where it's 30F or - 1
I don't want to mess with the air flow.
 

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My wife put one of these on her '19 Chieftain Classic.
I can see how it would restrict the air flow, but has anyone had any issue with long term use causing rear cylinder damage?
 

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Discussion Starter #6
Not sure it restricts it so much as redirects the air flow. If you put your hand down while riding you can still feel just as much heat, it is just going past the side covers instead of your inner thigh.
Look at engine design rear cylinder is set back behind leg so your leg can't restrict. Cooler or killer
 

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This is exactly why i have not pulled the trigger on a CC. Understanding that thermodynamics has a HUGE play on an air cooled engine, i just cant bring myself to change the dynamics that much and just hope for the best. Thermodynamics has such a large impact that Indian has moved the horn from behind the horn cover to out front to help increase the air flow. And there is no way the horn was blocking that much air, but enough to warrant moving it i guess. The crotch cooler affects the thermodynamics much more than the horn.

There are plenty of bikes out there with them and don't have any obvious or apparent issues so far. Maybe it will have some effect on longevity, and maybe not, but that would gnaw on my mind every time i ride my bike if it had a CC, and with my luck it would burn up the rear valve stem seals. That worry would have the potential to immensely diminish my enjoyment. If i was in the habit of getting a new bike every 30k or 40k miles then i would probably put one on and enjoy the cooling affect. But i keep mine until much closer to 100k and more so i just dont want to chance it.
 

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Discussion Starter #8
This is exactly why i have not pulled the trigger on a CC. Understanding that thermodynamics has a HUGE play on an air cooled engine, i just cant bring myself to change the dynamics that much and just hope for the best. Thermodynamics has such a large impact that Indian has moved the horn from behind the horn cover to out front to help increase the air flow. And there is no way the horn was blocking that much air, but enough to warrant moving it i guess. The crotch cooler affects the thermodynamics much more than the horn.

There are plenty of bikes out there with them and don't have any obvious or apparent issues so far. Maybe it will have some effect on longevity, and maybe not, but that would gnaw on my mind every time i ride my bike if it had a CC, and with my luck it would burn up the rear valve stem seals. That worry would have the potential to immensely diminish my enjoyment. If i was in the habit of getting a new bike every 30k or 40k miles then i would probably put one on and enjoy the cooling affect. But i keep mine until much closer to 100k and more so i just dont want to chance it.
I moved horn on my cheiftain because it slowed air flow. Working with heat transfer I'd never use crotch cooler.
 

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My wife put one of these on her '19 Chieftain Classic.
I can see how it would restrict the air flow, but has anyone had any issue with long term use causing rear cylinder damage?
Do a search on the forum. This has been covered before. There is (at the least) anecdotal evidence indicating that the "crotch coolers" pool excess heat around the rear cylinder head, thereby causing overheating of the rear head & cylinder and (potentially) the burning of the valve stem oil seals. It stands to reason that any device that retards upper & rearward air flow from the rear cylinder/cylinder head/exhaust header will serve to "pool" that hot air around those parts that require consistent cooling by air flow. Hot air rises (convection) and it can be trapped within anything that restricts it's ability to do so.
 

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Have had the Capt. Itch almost since I bought my DHC'tain in Aug. 2016. I have had no issues that I'm aware of and I ride year 'round, even when it's above 95º in the Carolinas in July & August.

Hope to de-cat one day, but just haven't gotten around to it.





BD
 

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Working with heat transfer. Something I observed is bikes with crotch coolers. Interesting people install them and comment it helps keep your leg and body cooler. Cylinder still create same amount of heat so where did heat go......... It's in the cylinder. Crotch cooler slowes air flow therefore heat transfer. Remember rear cylinder air. Temp already raised by front cylinder therefore slowed transfer to 2nd. Cylinder. Newer cylinder deactivation only occurs at low air flow or idle.
I always worry about how covering up the rear head may cause it to hold heat, heat and air cooled engines. ..well you know

I have not installed one because I want to give the read head/cylinder the best opportunity to get blasted with air. My Rinehart Slimline Dual Exhaust system let's the Thunder Stroke run much cooler so I'm not experiencing any discomfort.

Sent from my SM-S903VL using Tapatalk
 

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The main benefit for me is that it stops radiated heat from hitting my inner thigh, especially when stopped in traffic on a hot day.
Stopped in traffic on a hot day is when the engine gets the hottest and has the most need for that heat to escape, and that's what would worry me to no end. I am glad you like and have had good luck with it though, that's what matters most.
 

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New folks to Harley, Believe that the rear cylinder runs hotter also... Simply Not true... In Fact it is measurably Cooler...certainly when sitting still...Why????
Splash Oil!!!!! Even Dry Sump Systems have some, ...semi dry???? Prolly more,... but, Not something I worry two Shits about...
 

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Bought one, installed it, and it rubbed the underside of my tank. Removed it, cut the openings out as large as possible, reinstalled it, and it rubbed the underside of my tank. Sold it.
 

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I had a Cap’n Itch CC for a while.
It only kept the heat around the rear jug when stopped. When moving at road speed, the CC wings out and circulates air around the cylinder....
Agreed. In my post above, I should have stipulated that the issue of retaining hot air around the rear head & cylinder is primarily a problem while the bike is idling or moving quite slowly, as in a traffic jam or slow parade. Once the bike is moving along above 20 MPH (or so) the crotch coolers will probably be a non-issue.
 

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Discussion Starter #19
I disagree I've done test with thermcouples at 4 points with crotch cooler and with out with cooler it ran 40 plus hotter at cylinder at road speeds and. Over 80 degrees at idle. This proved it restrict heat transfer
 

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I was never a believer until my cigar run for Casa Fuentes this summer — 110 degrees plus across the desert for several hours. Could not find a comfortable position where my legs weren’t toast. I’m gonna do that cat-gut first but if that doesn’t do it, Captain Itch here I come.
 
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