Four front tire flats in the space of a week....
10-31-10, 02:07 PM
#26
Artificial Member
Join Date: Jan 2010
Location: Cyberspace
Posts: 7,158
Bikes: Retrospec Judd, Dahon Boardwalk, Specialized Langster
Mentioned: 31 Post(s)
Tagged: 0 Thread(s)
Quoted: 6766 Post(s)
Liked 5,477 Times
in
3,223 Posts
I never took high school physics! I did take a freshman physics class. Everything was counterintuitive but could be proven mathematically. I never took chemistry, either.
So yeah, you're right, I'm not sure if it's CO2 compressing (which would make sense) or CO2 leaking out of the porous butyl that would account for the observation that any tire I've filled with CO2 loses pressure relatively quickly. (Relatively = more than a few hours, less than a full day). So I'm hoping you can explain why this is?
L.
So yeah, you're right, I'm not sure if it's CO2 compressing (which would make sense) or CO2 leaking out of the porous butyl that would account for the observation that any tire I've filled with CO2 loses pressure relatively quickly. (Relatively = more than a few hours, less than a full day). So I'm hoping you can explain why this is?
L.
This is a link to a recent Lennart Zinn post concerning a portable nitrogen gas inflation system
Luis you are absolutely correct about getting to a regular floor pump after an emergency inflation with CO2. Inflation with CO2 will be remarkably deficit the following day but it for sure will get you through the longest of day rides.
10-31-10, 02:17 PM
#27
Artificial Member
Join Date: Jan 2010
Location: Cyberspace
Posts: 7,158
Bikes: Retrospec Judd, Dahon Boardwalk, Specialized Langster
Mentioned: 31 Post(s)
Tagged: 0 Thread(s)
Quoted: 6766 Post(s)
Liked 5,477 Times
in
3,223 Posts
You are right about that rim tape. I was very annoyed and exasperated with repeated flats one summer. When I found the cause, a little, tiny lack of nipple seat coverage because the tape had shrunk I was amazed.
10-31-10, 03:15 PM
#28
Senior Member
The worst, should you have a couple pinch flats and you don't have enough Co2 cartridges , you are screwed.. I feel much more secure with a real frame pump.
__________________
Pray for the Dead and Fight like Hell for the Living
^ Since January 1, 2012
Pray for the Dead and Fight like Hell for the Living
^ Since January 1, 2012
10-31-10, 06:10 PM
#29
train safe
Join Date: Dec 2005
Location: Broomfield, CO
Posts: 801
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times
in
0 Posts
the ziplock protects the tube much better than the cardboard, which sort of falls apart if it gets any moisture on it. The talcum powder works really well too.I also agree on carrying a pump. A slow leak will wipe out your CO2 supply... you can always pump up a slow leak and make it home.
train safe-
10-31-10, 06:27 PM
#30
Senior Member
Thread Starter
Join Date: Aug 2009
Location: Minneapolis
Posts: 5,751
Bikes: 2022 Salsa Beargrease Carbon Deore 11, 2020 Salsa Warbird GRX 600, 2020 Canyon Ultimate CF SLX disc 9.0 Di2, 2020 Catrike Eola, 2016 Masi cxgr, 2011, Felt F3 Ltd, 2010 Trek 2.1, 2009 KHS Flite 220
Mentioned: 20 Post(s)
Tagged: 0 Thread(s)
Quoted: 4387 Post(s)
Liked 3,016 Times
in
1,865 Posts
For the record, CO2 molecules are actually larger than N2 molecules (think about it, 3 atoms/molecule instead of 2). Yet it is true that CO2 escapes tires more rapidly than N2 as it has a much greater permeability in rubber. As others have said, the CO2 is just to get you home.
As to rim tape, I notice that it has migrated a little from the valve hole, exposing the sort-of sharp edge of the wheel rim. None of my 4 flats originated that way (none of the holes were in that location), but it did give me pause. Talking with my LBS guy, he pointed out that innertubes are reinforced with a thick layer of rubber in the area around the valve stem, and said that it was very unlikely to cause a problem.
As to rim tape, I notice that it has migrated a little from the valve hole, exposing the sort-of sharp edge of the wheel rim. None of my 4 flats originated that way (none of the holes were in that location), but it did give me pause. Talking with my LBS guy, he pointed out that innertubes are reinforced with a thick layer of rubber in the area around the valve stem, and said that it was very unlikely to cause a problem.
10-31-10, 11:04 PM
#31
Senior Member
Join Date: Oct 2010
Location: NorCal
Posts: 188
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times
in
0 Posts
And I love my Conti Gator Hardshells. Multiple people in my club running them, only seen a flat once.
