Scorpion King

Just wanted to float a thought out there:

What is the rough energy requirements to pump a road tire (say to 90-100 PSI) with a mini pump? [yeah, i know, it might not be possible to really even get the tire to that PSI.]

If you get a flat, are you losing a good amount of energy manually pumping a tire?

e.g. Going on a long trip into the mountains, and you get a flat. Time is not an issue though, but saving precious energy is -- say for hills. Definitely use CO2 if you have both the pump and co2?

I figured that some calculation of this would be:
Volume of air displaced in pump x number of times on average needed to get tired up to 90 PSI. say you only want to spend a couple minutes doing this, so therefore you could calculate total power/force required. it seems if only aerobic energy is used for this then the overall effect on performance is negligible. wear an hr while doing this to see what zone you are in?

badhat

i just use a pump cuz its cheaper and god forbid i get more than one flat in the middle of nowhere.

valygrl

Is this some kind of mental exercise, or are you really concerned?

CO2 is the way to go b/c of time & you can get the tire inflated to the proper pressure. I carry both a CO2 and a mini pump, for the 2nd flat.

BotByte

I got co2 only for that use that if I need to lean over and inflate a tire quickly, other than that, I have a body pump on every one of my bikes

It's nice to have in your heavy tool bag, but not needed if you have a mini pump

mmmdonuts

merlinextraligh

+1. C02 is the lightest, quickest, easiest answer. 58 gram Blckburn mini pump is light insurance for the rare second or third or 4th flat.

Combination of the two gets you the best of both worlds, quick and easy, but still light and security against multiple problems.

caloso

If you're that tight on energy expenditures, you might consider bringing a Gu or a banana as well as a pump.

UCIMBZ

Instead of sitting in front of the computer and wasting everyone’s time, you could have inflate a tire and experience it first hand.

Harlan

I use the Lezyne Pressure Drive S and it can get to 90-100 PSI. Quite compact - I put it in my back pocket rubber banded to a tube, lever, my medical insurance card etc.

I'd say if you're racing and think you'll be able to change a flat and still be competitive then get CO2 but for training or recreation there's no reason in my mind not to use a pump. It doesn't take that long to pump a tire up.

valygrl

^^^ group ride, 35 degrees out, 10 people standing around waiting for you to fix your flat ---> CO2

caloso

That's true. And why I take the belt and suspenders approach: CO2 and new tube for the first flat; pump and patch kit (and "go on without me--I'll catch up") thereafter.

Harlan

Fair enough, I guess I could qualify my statement with solo training - except in cases of dangerous situations and inclement weather.

kleinboogie

245 Watts and somewhere between 20 and 30 kj.

Carbon Unit

I have carried a few different pumps but now only carry CO2 and three or four cartridges. First, I had a Road Morph, it worked well and I could get to 120 PSI with some effort. When I changed bikes, I didn't want to hang it from the top tube so I bought a Blackburn frame pump but I couldn't get enough air into the tire. I went to CO2 and have never had more flats than I have cartridges in the four years that I have been using it.

nacler22

+1

wrr1020

I always bring a mini pump with me and throw it in my jersey. I usually seat the tube with the mini pump and then use my c02 to inflate the rest of the tire. Always good to have in case your c02 fails for some reason and your not stranded in the middle of nowhere. You may not get to 100 with the hand pump (depending on the pump) but it'll give you enough air to get home.