When I have an early a.m. race I like to fill the tires/clinchers up the night before due to having to have 4-hands (me/wife) with the inflator, etc;…so, I always pump it above manuf. suggested psi.
that way I am not rushed in the a.m. and if I blow a tube I can change it that night…with that said, anyone know (on avg) how man p.s.i is lost overnight?(any?)
I am not sure of the exact amount, but if you are using latex tubes it is much more than butyl rubber.
bump…take a guess <5psi or >5psi?
So… you want us to guess how much air you’ll lose out of your tires overnight without knowing the following pieces of information:
Ambient temperature at time of filling
Anticipated ambient temperature the next morning
Water content in the air
Condition and construction material of your tubes
Phase of the moon
Your credit card number
And even if we had all these pieces of information, it’d be a losing battle from the get go. Is airing your tires in the morning really that much of a hassle when compared to the level of conjecture you’re employing by filling them the night before?
My best recommendation is to change your pre-race procedure. Barring that, perhaps do a test run the night before the night before your race and use your data point as you see fit.
Yes, doing this in advance would have been the “bright” thing to do but I “just” noticed my pump gauge has been inaccurate over the last year…I used a better gauge (today) to measure and found out…so, I don’t have the luxury of checking.
Waking the wife up early to pump my tires before I drive 1.5hrs to the race, with the crack pipe is not an option and I don’t trust others.
So, I will assume you have NO idea as you provided no useful information…but tks for your conjecture.
At sea level you we loose 2.1875 psi in 8 hrs.
I lose 20lbs in a week on my training bike. It still has the stock wheels and tubes so I am not sure what is the make of the tube.
I think its an intersting question, but im confused why you cant blow up your tires by yourself? It only takes me and everyone I ride with 2 hands.
I can’t pump up my disc without help (crack pipe)–I think that’s what he’s talking about.
That said, to the OP, get someone in transition to help you. I do this every race. It’s a nice way to talk to someone on race morning and only takes a few seconds. Often times, they’ll need help with something too. I try to find the biggest newb around as it seems to make him feel good, like I picked him because he looked like he really knew what he was doing :-).
Be careful not to pump them up too much. At one chilly early morning race I was at when the sun came over the hill and hit the bike racks two bikes’ tyres blew up. Unfortunately it was just before the start and most people were already in the water.
Having said that you will lose some pressure overnight, but not much (5-10psi at a wild guess). My clinchers hold there air pretty well but the tubulars on my deep rim race wheels would lose 20psi overnight.
Agree with the others, you should be able to pump up your tyres by yourself! Does you pump not have a lever to lock it onto the valve?
In addition to what Spiridon Louis said, if you are afraid of blowing out your tube, make sure you’ve already mounted the tires and ridden on them at least once before race day. That way you should avoid any errors in mounting the tire.