tyre valve.

sniggings

Am I doing something wrong or do I need a new pump?

Got a flat on the way home, 1 inch nail :mad: change went smoothly until I came to pump the trye, the pump is a lezyne tech drive, good pump but I have to screw the tube on as it seems not to be able to be pushed on, which is good as it stays put, but the problem comes when trying to remove it,as it unscrews the inner tube valve too (presta),so all the air comes out, is it me or the pump?

armyknife

I don't know, but one of these will get you home and work very reliably:

http://www.amazon.co.uk/gp/product//B00HSHFHOM/ref=twister_dp_update?ie=UTF8&psc=1

sniggings

cheers, I googled it and it seems some inner tubes have removable valve cores some don't, they tend to be loose when new, add to that the pump I have has a screw fitting, hence the problem...seems my options are buy a different pump, buy different inners or buy or one of these http://www.wiggle.co.uk/lifeline-valve-core-remover/?sku=5360644907

I took the last option as it's the cheapest, and I like my pump and continental inners.

brat

sniggings wrote: »

cheers, I googled it and it seems some inner tubes have removable valve cores some don't, they tend to be loose when new, add to that the pump I have has a screw fitting, hence the problem...seems my options are buy a different pump, buy different inners or buy or one of these http://www.wiggle.co.uk/lifeline-valve-core-remover/?sku=5360644907

I took the last option as it's the cheapest, and I like my pump and continental inners.

Most high pressure portable mini pumps screw on to the valve core.
I feel your pain, because this happened to me on a sportive a while back, and I couldn't get the valve to stay in the tube. It kept on unscrewing with the pump. I eventually got someone to stop who had pliers, and I screwed the valve core on very tightly. It then stayed in the tube when I unscrewed the pump. I had another three such tubes at home, but I've never used them since.

Cycrow

I had this problems once on the way to work.
once it was loose i couldn't tighten it anough to stay on when i unscrewed the pump, as it would always unscrew the valve before the pump.

i ended up just going to the local halfords to get a new inner tube

modsandmockers

Punctures in modern motor vehicle tyres are practically unheard of, and there is never any problem with different types of valve and/or different types of pump.

When I bought my current bike about 5 years ago, it was an end-of-season reduction from around £800 to around £250, and the bike came complete with Continental Sport tyres (which were said to be as good as puncture-proof) and included the manufacturer's offer of a replacement cover if the tyre should ever be punctured.

I don't do many miles, but most of them are on cycle paths and tow paths. I had three punctures in the first couple of years, and because the bike has hub brakes and hub gears, a roadside repair is an extremely unattractive proposition.

Cyclists frequently complain about their lowly place in the road users' pecking order, but the thing which most deters me from more adventurous bike rides is the risk of getting a puncture.

No doubt there is some kind of trade-off between rolling resistance and puncture resistance, but the motor industry (including motor bikes) seems to have found an acceptable compromise - why are bicycle tyre punctures still such a problem?

brat

modsandmockers wrote: »

No doubt there is some kind of trade-off between rolling resistance and puncture resistance, but the motor industry (including motor bikes) seems to have found an acceptable compromise - why are bicycle tyre punctures still such a problem?

Bikes tyres don't puncture very often really. I've had half a dozen punctures in the last 2 years or 15,000 miles of cycling, so it's not that big a deal, especially as they can be sorted in 5 minutes.

Weight is the primary issue, especially for performance road bikes, given that they are entirely self propelled. My bike tyres weigh 210 grams each, but despite that, have added puncture protection and low rolling resistance. The desire to keep the rolling mass as low as possible will always result in a compromise between performance and reliability.

I could buy tyres and tubes that doubtless would puncture less often, but I don't want to, because I like the performance, grip and look of the tyres I have.

armyknife

modsandmockers wrote: »

Punctures in modern motor vehicle tyres are practically unheard of, and there is never any problem with different types of valve and/or different types of pump.

When I bought my current bike about 5 years ago, it was an end-of-season reduction from around £800 to around £250, and the bike came complete with Continental Sport tyres (which were said to be as good as puncture-proof) and included the manufacturer's offer of a replacement cover if the tyre should ever be punctured.

I don't do many miles, but most of them are on cycle paths and tow paths. I had three punctures in the first couple of years, and because the bike has hub brakes and hub gears, a roadside repair is an extremely unattractive proposition.

Cyclists frequently complain about their lowly place in the road users' pecking order, but the thing which most deters me from more adventurous bike rides is the risk of getting a puncture.

No doubt there is some kind of trade-off between rolling resistance and puncture resistance, but the motor industry (including motor bikes) seems to have found an acceptable compromise - why are bicycle tyre punctures still such a problem?

I'm not sure where to start with this one. :hmm:


Maybe I'll just go with, because cars are so Epic?

sniggings

modsandmockers wrote: »

Punctures in modern motor vehicle tyres are practically unheard of, and there is never any problem with different types of valve and/or different types of pump.

When I bought my current bike about 5 years ago, it was an end-of-season reduction from around £800 to around £250, and the bike came complete with Continental Sport tyres (which were said to be as good as puncture-proof) and included the manufacturer's offer of a replacement cover if the tyre should ever be punctured.

I don't do many miles, but most of them are on cycle paths and tow paths. I had three punctures in the first couple of years, and because the bike has hub brakes and hub gears, a roadside repair is an extremely unattractive proposition.

Cyclists frequently complain about their lowly place in the road users' pecking order, but the thing which most deters me from more adventurous bike rides is the risk of getting a puncture.

No doubt there is some kind of trade-off between rolling resistance and puncture resistance, but the motor industry (including motor bikes) seems to have found an acceptable compromise - why are bicycle tyre punctures still such a problem?

I have the sport contacts and find them very good, been using them a year now and only had 2 punctures, both were 1 inch nails, going straight into the tyre.

I guess the tyre pressure has a lot to do with it, bike tyres having a lot lower pressure than motor tyres.

brat

sniggings wrote: »

I guess the tyre pressure has a lot to do with it, bike tyres having a lot lower pressure than motor tyres.

That very much depends on the type of riding you do, and the type of tyres you have. Most bike tyres have higher pressures than car tyres. My road bike tyres are generally up at 120psi. My car tyres are about 38psi.

sniggings

brat wrote: »

That very much depends on the type of riding you do, and the type of tyres you have. Most bike tyres have higher pressures than car tyres. My road bike tyres are generally up at 120psi. My car tyres are about 38psi.

yeah true, was getting mixed up.

maybe the thickness ofthe tyre rubber and the middle of the road doesn't tend to have all the crap you find in the gutters and on tow paths.