RoadBikeReview.com's Forum Archives - General


Archive Home >> General(1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 )


Noob air question....(7 posts)

Noob air question....joe friday
Nov 17, 2003 11:13 AM
what can I expect from road tire/innertubes when it comes
to holding air pressure?
On my mtn. bike,
I used to shred ten dollar bills buying the ultralight tubes
--finding my rims sitting on the floor more often then not.
So i finally gave up--I *hate* having to pump up tires all
the time!--and now run heavy, cheap tubes and can easily go
6 weeks without adding air--and I like it that way.

will decent road tubes hold air pressure that long also?
TIA!!
No53T
Nov 17, 2003 12:36 PM
Decent road tubes will go from 120psi to 100psi in about a week, best case. A roady's most used tool is his pump.
ok, any ideas on latex vs. butyl..joe friday
Nov 17, 2003 1:11 PM
i'm looking at a pair of Vittoria Open Corsa EVO CX
in 23cm--i reeealy wanted some 25cm tires, but they're
hard to find etc..
all this is going on a fixed gear track bike for the
road. any thoughts on how 'better' tubes would/wouldn't
serve these tires? should I expect a lot of flats etc..?
Should I go with wider--and heavier tires, since i'm new
to the road? Sorry if i'm wandering.. I'm new to this.
ok, any ideas on latex vs. butyl..russw19
Nov 17, 2003 2:01 PM
If you are building a fixed gear for the road, then I have to assume you are just using it as an urban commuter type bike. Nothing too high performance, right? If so, why buy lightweight tubes? They won't give you any extra advantage. If they made you any faster (which they won't) you will give all that advantage up by not being able to shift to capitalize on that extra speed anyways. They won't make your life any easier as they flat more often and cost more when they do and are harder to patch (latex) so why do it?

On to your other question... you will have to pump tires up much more often with road tires. The reason is they are a higher pressure. It's chemistry. The higher pressure inside the tube will naturally try to equalized with the lower pressures outside the tube. The higher the pressure difference the faster this takes place. That's why you have to pump up road tires more. The pressure starts out higher and will try to equalize faster, plus because they are high pressure and low volume (opposite of mtb tires) you will notice a 10 psi decrease much more on the road tire than the mtb tire.

Russ
thanks very muchjoe friday
Nov 17, 2003 3:22 PM
what you say has been my experience with atb latex tubes--
expensive and finicky.
My real wish is that I could get 25cm tires because i'm new to the road and worry about not getting enough grip with 23's but, again, it's really a cost thing on my part.
thanks very muchbc165
Nov 17, 2003 5:55 PM
check out...
http://www.biketiresdirect.com/default.asp
they're on this website under hot deals
they have conti and michelin in 700x25
Geta grip53T
Nov 18, 2003 10:39 AM
There won't be any performance difference between 23s and 25s, grip is not an issue, since you won't be exploring the limits of traction on this single speed. Besides, the physics wonks will explain to you that the area of the contact patch is independent of tire width.

My comments about losing your top 20 psi in one week are based on butyl tubes, nobody trains on latex. Hell, nobody I race with races on latex.