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Update On Sealant In A Double Tubed Wheel



 
 
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  #1  
Old July 31st 18, 07:28 PM posted to uk.rec.cycling
Bret Cahill
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Default Update On Sealant In A Double Tubed Wheel

I'm not sure why I didn't think of putting sealant in the double tubed wheel earlier, maybe the concern was weight.

The double tubed front road tire has about 60 gms of sealant in each tube with no flats after 850 km. The aqueous sealant doesn't seem to be drying out on the 70C pavement so maybe they _have_ been adding polypropylene glycol all along.

Without sealant you need to start over again each time you want to top off because 2 tubes w/o sealant never leak at the same rate. There's no way of knowing how much air to put into which tube so both tubes need to be completely deflated then refilled with equal amounts of air.

With sealant the air leaks out of both tubes at about the same rate -- something I should have wondered about _before_ experimentation but didn't realize until after actually adding the sealant. You cannot think without talking or writing as Warren Buffet pointed out. Each week the pressure drops from 600 to 400 kPa so all I need to do is add 100 kPa to each tube and it's close enough to 50 - 50. Maybe after several weeks or months of topping off it'll need a reboot.

On the down side the double tubed sealant wheel,

1. weighs almost 2 kg,

2. you might want to try this outdoors first. If you release all the air at once from one tube every last drop of sealant will come flying out as well spraying the ceiling, walls, furniture, etc. The air needs to be alternately released from each tube in stages. If one valve is clogged with sealant you can not just remove it. Unscrew it slowly, release some air, then shove it back in.

3. Slime will probably clog at least one valve.


Bret Cahill


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  #2  
Old August 3rd 18, 07:30 AM posted to uk.rec.cycling
Bret Cahill
external usenet poster
 
Posts: 875
Default Update On Sealant In A Double Tubed Wheel

I'm not sure why I didn't think of putting sealant in the double tubed wheel earlier, maybe the concern was weight.

The double tubed front road tire has about 60 gms of sealant in each tube with no flats after 850 km. The aqueous sealant doesn't seem to be drying out on the 70C pavement so maybe they _have_ been adding polypropylene glycol all along.


That should have been propylene glycol

Without sealant you need to start over again each time you want to top off because 2 tubes w/o sealant never leak at the same rate. There's no way of knowing how much air to put into which tube so both tubes need to be completely deflated then refilled with equal amounts of air.

With sealant the air leaks out of both tubes at about the same rate -- something I should have wondered about _before_ experimentation but didn't realize until after actually adding the sealant. You cannot think without talking or writing as Warren Buffet pointed out. Each week the pressure drops from 600 to 400 kPa so all I need to do is add 100 kPa to each tube and it's close enough to 50 - 50. Maybe after several weeks or months of topping off it'll need a reboot.

On the down side the double tubed sealant wheel,

1. weighs almost 2 kg,

2. you might want to try this outdoors first. If you release all the air at once from one tube every last drop of sealant will come flying out as well spraying the ceiling, walls, furniture, etc. The air needs to be alternately released from each tube in stages. If one valve is clogged with sealant you can not just remove it. Unscrew it slowly, release some air, then shove it back in.

3. Slime will probably clog at least one valve.


Bret Cahill


 




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