Monday, May 11, 2009

Law of conservation of punctures

If somebody would have asked me at the beginning of January, how many flat tires I usually have per year, I would honestly have said "none". Now, times have changed, and this number has increased rapidly. Today I repaired my 7th puncture for this year -- I had 3 on the back wheel and 4 on the front wheel. On the back wheel I have a new inner tube now and never had problems ever since. And I will also change the inner tube of the front wheel tonight.

Some people say that if you have puncture once, you're very likely to have more. It's a kind of conservation law -- the series of punctures will continue. I don't believe in that. But I believe in fatigue of material. The last three punctures on the front wheel I all had inside, and they were quite big (today's puncture was nearly 1cm). My inner tube has problems with the rim as far as I can tell, as it got too brittle over the years.

Hopefully, after changing the inner tube on the front wheel, this series of punctures will stop for a while. Ok, I got a little bit angry when I walked out of the university on these evenings, just wanted to get home and had yet another flat tire, but it also has some positive sides: By now I'm an expert in repairing punctures ;-). I'm pretty fast and don't cover myself in dirt (except the hands).

In case you never repaired a flat tire, don't worry -- it is very easy. Almost every repair kid includes instructions, and many can be found in the internet, e.g. How to mend a puncture (which includes the very interesting "art of cycle maintenance"), The easy way to repair a puncture and Patschen picken (in German).

Well, so by now, on average, I have about 1 puncture/year . How many do you have? Can anyone beat my 7 flat tires for this year? I just hope I won't...

5 comments:

le homme au velo said...

Hi Anna. I once had a Peugeot light Touring Bike with Dropped Handlebars and Michelin Tyres and I was forever getting Punctures. No problems with the actual Bike itself just loads of Punctures. The Bike I had before was a Three Speed Sturmey Archer Raleigh Triump Bike which I had in my Teens in 1967 until I sold it to a Friend of mine. I had it for around 8 Years and no Punctures whatsoever. I just was not satisfied and wanted a Racer with loads of Gears so I got the Peugeot and Ended up Cursing it for having so many Flat Tyres.

I eventually got a Mountain Bike and had my first Puncture after two weeks then things settled down for a while until I went Touring in Waterford. I brought a spare Inner Tube with me just in case and sure enough I got a Puncture after coming down a big Hill with Road Works and a Rough Surface, I got a few more Punctures before I went Home a Week later. I got one every so often after that about once a Year. Which just goes to show there was something in those Old Dunlop Tyres on those Raleighs Years ago they never seemed to get Punctures much if at all. I have had several Bikes since the Mountain Bike and the Dutch Bike with the Kevlar Belt on the Schwalbe Marathons are Great I have not had any Punctures at all yet with it. I have a Brompton Folding Bike and I got a Puncture with it, it is very hard getting the Wheel off due to them being small. I guntered the Innner Tube and Gashed the Wheel Rim trying to get the tyre back on the Wheel, so in the End I brought the Bike to the Dealers and they fixed the Punctured and put th Wheel back on.

I am average at fixing Punctures and sometimes if I do not take my time the Tyre Deflates after a few Miles, so now I wait Longer to give it a Chance to Stick.

My New Raleigh Bike that I use for Long Distance and Touring has Puncture Resistant tyres so hopefully I will not have much trouble. It is amazing how things come back full Circle after all these years. I am back to a Raleigh Bike again.

maff said...

Sometimes I see people fumbling the inner tube between rim and tire when putting them back on the wheel.
A more elegant way is to place the slightly inflated tube in the tire and place them together on the rim. This avoids twisted and "buckled" tubes, which could cause out-of-rounds and snake-bite flats.

anna said...

Wow, le homme au velo! You have got some sort of experience with flats, don't you ;-).

Anonymous said...

This morning as I was about to leave for work I discovered I had a puncture. This wasn't such a big deal as I have a spare bike (or three!) so I put it away in the shed and took out the other bike and set off for work. A mile from home I went through a pile of broken glass and sure enough a mile further on and the tyre was flat. I have 2 spare tubes in my bag so pulled over, took the wheel off, changed the tube for a spare, put the wheel back on and started pumping. Nothing. The spare was obviously faulty, probably a patch that has come loose in my bag. I removed the wheel and fitted the second spare tube, this time pumping some air in before putting it in the tyre to check it was fine. After putting the wheel back on whilst pumping it back up properly the schrader valve screw snapped! Wheel off for third time, puncture patched and carefully pumped up I was on my way and only half an hour late for work. On my way home I called into the car/cycle superstore where inner tubes were on offer, 3 for 2 so I bought 3 new spares in preparation for next time!

le homme au velo said...

I am no Expert at fixing Punctures but I am getting better at it. Anonymous the same thing happened to me as Regards the Valve, I fixed a Puncture once and was Pumping up the Tyre and Leaned to much Sideways with the Pump and put to much Strain on the Valve and so broke it. I tok the Wheel back off and tried putting a Patch around the Valve but it did not Work. Luckily I was not to far from Home about 2k.

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