O.K. I got my first flat today. I am at home fixing it and noticed that the innertube I removed from the wheel is 700x18x25 while the innertubes the bike shop that sold me the bike supplied are 700x18x23. Does this matter? What is the difference between the 25 and the 23? Next, the presta valve on the flat is threaded and the valve on the new tube is not. Does this matter?
A difference in tube size like that really won’t matter unless you’re running 28’s or bigger. The 700 refers to your rim diameter, and the second to the tire cross section diameter.
As for the valve, it doesn’t matter whether it’s threaded or not.
Thanks!
Really bad f-ing Karma if you are not using Michelin tires and tubes!
If not, there is the reason for your flat.
Thats prolly it!
Nunc est bibendum!
You got a flat b/c your seat is too high.
You need to expand on that. I can’t wait to show this post to the lbs where I had my fitting.
Did you get it fixed? It can be a pain your first time on road tires. Mountain bike tires are much easier to learn on. I would recommend inflating the tire a bit and then deflating it several times before putting the full amount of pressure it to make sure the tube isn’t “pinched” between the tire and the rim.
Welcome to the forum!
Dan
www.aiatriathlon.com
Thanks, yes I got the tire on no problem! Right now the bike is up on the trainer until the week-end (my square job doesn’t allow me the luxury of rides during the week), but I will be sure to check the pressure before riding on it. Thanks again.
I was teasing! 
It’s initiation.
I’m sure your seat is perfect.
Welcome!!!