Testing Tubes etc....

g0g

Apologies this is such a beginner question! Anyway when you're finished laughing please could someone answer this question (plus one more!). So I got a hybrid bike a few weeks ago. Am entering Gaelforce West in a few weeks. Haven't had a bike in years so wanted to get used to taking wheels off and all that sort of stuff. Supposedly I'm meant to somehow get my pressure up to 100psi before cycling the bike on rough ground!?

1) Firstly, I saw on some website that before packing tubes with you, you should inflate them to test them first. Well I only pumped it up to 20-30psi and then it exploded in my face. Haha very funny I know... Does that mean tube is dodgy or was I doing completely the wrong thing? It was kinda getting bubbly in different parts and then popped. Beginner/Idiot mistake I'm guessing, but I wanna be sure!

2) With a standard portable mini pump do I have a hope in hell of pumping up to 100psi? Seems like such an effort to even get to 60 with this yoke??

Any help/advice much appreciated!:)

DirkVoodoo

g0g wrote: »

Apologies this is such a beginner question! Anyway when you're finished laughing please could someone answer this question (plus one more!). So I got a hybrid bike a few weeks ago. Am entering Gaelforce West in a few weeks. Haven't had a bike in years so wanted to get used to taking wheels off and all that sort of stuff. Supposedly I'm meant to somehow get my pressure up to 100psi before cycling the bike on rough ground!?

1) Firstly, I saw on some website that before packing tubes with you, you should inflate them to test them first. Well I only pumped it up to 20-30psi and then it exploded in my face. Haha very funny I know... Does that mean tube is dodgy or was I doing completely the wrong thing? It was kinda getting bubbly in different parts and then popped. Beginner/Idiot mistake I'm guessing, but I wanna be sure!

2) With a standard portable mini pump do I have a hope in hell of pumping up to 100psi? Seems like such an effort to even get to 60 with this yoke??

Any help/advice much appreciated!:)

100 PSI is with a tyre to create the resistance. Was the 20-30 done with only atmospheric pressure? If you want to test a tube, just pump it up with a small bit of air and leave it overnight, you don't need to go crazy

Minipumps, a lot of them are "rated" for 100 PSI, meaning they will get there eventually, but seeing as you are providing the work it really depends on your strength and patience. Personally, in a race situation, I would use CO2. You could be 20 minutes pumping up a tyre and in the end it's tiring, not good.

petethedrummer

1) In future just pump it enough to inflate it, I wouldn't go to any particular pressure if its not mounted under a tyre, there's nothing to stop it expanding and exploding, as you found out. I've only had one dodgy tube so far so I wouldn't go checking every tube. Just bring 2 if you're worried or a puncture repair kit. All you need is a few small patches, the tube of solution and a little bit of sandpaper, you won't even notice you have it. Don't bring the box or the bit of crayon or the large patches.

2) No. Those little pumps will just give you enough air to get home. You can get mini co2 cannisters that will pump up your tyres up further. But you only get one chance with them.

g0g

Thanks a mil, appreciate the advice! One other question while people are feeling helpful!

If a tyre says 700x28 I assume I should get a tube that falls within that range? The second number seems to vary - assume it's better buy too big than too small?

DirkVoodoo

700 is the tyre diameter in mm, 28 is the width.

Generally tubes fall into a range, as they are just filled with more or less air to suit different tyre widths. Pick one that is:

a) From a reputable brand (Michelin, Hutchinson, Continental)
b) Not too expensive (don't worry too much about weight)

SubLuminal

I've gotten a tyre to 100psi with one of these..

http://www.chainreactioncycles.com/Models.aspx?ModelID=26704

but it was in a bike shop, took a long time, was very hard and I was only doing it to see if I could do it. I wouldnt bother to try again!