Punctures every week - what the hell?

pickarooney

Since I changed bikes a couple of months ago (mountain bike was stolen, was given a racer as a replacement) I've been going nuts replacing tubes every single week. I do a 10km each way cycle to and from work over normal asphalt roads and can't really just accept that it's blind misfortune. I've changed the back wheel (for other reasons, spokes were jiggered), both tyres, over a dozen tubes between the two wheels, the rubber inlay band... not once have I found a piece of glass, nail or thorn when changing the tyre and yet I can go no more than 5 days without a long walk home or arriving half an hour late for work. I asked in the local cycle superstore (yeah, I know, might as well ask a particularly distracted three-year old) about it and his assertive response was that I was underinflating my tyres, suggesting I whack them up to 8 bar. This I did and within fifteen minutes my back tyre blew out going around a bend. Fun times with a lorry coming the other way!

I've pretty much given up on the accursed machine and will probably be buying a new bike next month. Not sure what type of rothar to go for - the thing is I like the increased speed of the racer, but cannot be having with the hassle, but that's for another thread.

So, anyone got any last suggestions before I toss the thing into the gears of an onrushing combine?

Snapper1

1. Check your not pinching the new tube (between the tyre and rim) when you change

2. Check the rim tape is covering all the spokes and nothing is protruding

3. Check the inside of your tyres v v carefully as there could be even the smallest shard thats causing the problem under pressure

all else fails... get armidillos

flickerx

pickarooney wrote: »

So, anyone got any last suggestions before I toss the thing into the gears of an onrushing combine?

I'd agree with Snapper1 on his suggestions. Apart from them, cant think of what it might be.

If you're giving up on the racer let me know, I might take it off your hands

blorg

Every week is a lot, once a month or two months might be normal if you were doing high mileage. Of course depends on the roads you are cycling on.

In fairness to the bike shop, if you are getting punctures but can't find any object the first thing that would be suspected would be that you are underinflating and getting pinch flats. Are you getting two small holes in the tube, close together? That's a pinch flat (or "snakebite.)

If you punctured anyway even with the high pressure, as Snapper says could be a rim tape/spoke issue.

Again as Snapper advises if you get Armadillos you will not puncture again.

pickarooney

The holes tend to be single pierce marks, consistent more with a sharp object than lever/pinch damage. When I got the new back wheel, the guy changing it managed to puncture one tube while putting the tyre back on and the replacement was punctured by the time I got home (and I drove the 15 minute journey!). I've been over and over the rim tape, and have almost got over that horrible feeling of running your finger over a potential minefield of glass shavings and never once found a foreign object on either wheel. What really throws me is that it's not a question of a few minutes before I get a puncture, but a matter of days or around 80-100km before the inevitable happens (apart from that last time when it blew 5km after I inflated to 8 bar).

Is there such a thing as a higher or lower quality inner tube? I've been buying the shop-brand at €2.50 a pair and would happily stretch to a branded tube if I thought there was a real difference.

I had a look at a review of armadillos. They sound sweet, but I'm sceptical. Must see if I can get them here in any case.

Thanks for the replies so far.

Raam

Do you always get the puncture at the same position in the tube?

kenmc

Can you narrow it down to a particular place on the wheel/tyre? If you always line up the logo on the tyre with the valve hole (or directly opposite the valve - as long as it's consistent) then if you get punctures in the same area or position all the time then it's easy to look in that area.
What size tyres are you running? And what pressures? Look out for any little cuts in the tyre and see if there's a sliver of glass embedded inside, that's not aparent either on the outside or the inside of the tyre, even by rubbing your fingers. Given that you get a period of time between punctures, this is much more likely than there being an obvious shard. Also when you put the tyre back on the wheel, before you go pumping it up go around the wheel on both sides, and push the tyre away from the wall of the wheel to ensure that you don't have the tube trapped - you should see the rimtape all the way around (although we've established that you don't have snakebites, it doesn't hurt to do this as a matter of course anyway).
HTH
K

Muller_1

You should check the tube after each flat to see where on the tube the puncture is even if you are putting in a new tube. If it's the same place every time, you may have a nick on your rim or the rim tape maybe poor. If it's the same type of puncture but in a different place you may have a tinny piece of glass or wire floating around in your tyre]

The best investment you can make is a good set of tyres for a commuting bike. I've a around trip of 45km everyday and only get a flat about once a month, but I change my tyres about every 4 months. Try probikekit.com for very good deals on tyres usually half the price as in the shops here.

pickarooney

Raam wrote: »

Do you always get the puncture at the same position in the tube?

More or less, yes, about 10-15 centimetres either side of the valve on both wheels.
I got the most resistant tyres I could find a couple of months back, but I'm open to suggestions for better ones.
I use 700x19-23 tubes, FWIW.

Raam

pickarooney wrote: »

More or less, yes, about 10-15 centimetres either side of the valve on both wheels.

In that case, the two posts following my first one should help find your problem. Best of luck.

kenmc

same place on BOTH wheels? wierd.

blorg

Muller_1's PBK suggestion is a good one, they have folding Continental Gatorskins for around the £15 mark, cheaper than anywhere else. These tyres are not quite as good as Armadillos for puncture resistance but handle a lot better. From your story however I am imaging that you really don't want to get any punctures at all and if so I would think Armadillos would be the better choice for you.

TinyExplosions

do you screw the nut that goes on the valve on very tightly, or at all? That close to the valve sounds like it could be either
a) too tight, and pulling the tube too close to the rim
b) not on at all, and the movement of the valve is holing your tube somewhere

pickarooney

TinyExplosions wrote: »

do you screw the nut that goes on the valve on very tightly, or at all? That close to the valve sounds like it could be either
a) too tight, and pulling the tube too close to the rim
b) not on at all, and the movement of the valve is holing your tube somewhere

I would say neither, I screw it until it stops turning, but don't force it beyond that.

The thing about getting new tyres is that, if the damage is being caused on the inside, that'll be of no help at all.

On the subject of tubes, do you guys go more tubes that are barely larger than the rims and won't fall off if you don't put on the tyre or tubes with a couple of cm breathing space? Although I match the sizes on my tubes to my tyres (and rims), they never fit snugly.

blorg

I just buy tubes that match the diameter of the rim and width of my width of my tyres (700x23c) and have never had a problem. What do you mean by "don't fit snugly?" Are your tubes too big or too small? It is possible I guess that you have the wrong sized tubes but very unlikely.

pickarooney

They're a little loose, although the tubes and tyres are both 700 diameter and the rim 23mm, tubes 19-23.

dub_skav

Tubes need to inflate in both directions - out and in - so they need to be a little loose, i.e. you shouldn't need to pop them on to the wheel like you would a tyre.

I use nutrak tubes myself and find them decent. I've been commuting 10 km each way for 6 months and have been doing a good bit of cycling on weekends, I've had about 5 punctures in that time

kenmc

pickarooney wrote: »

They're a little loose, although the tubes and tyres are both 700 diameter and the rim 23mm, tubes 19-23.

How do you mean the rim is 23mm? Do you mean that they're 700x23 tyres? if so the 19-23 should be fine...

oobydooby

When you're checking the tyre again for bits of glass etc. , as mentioned above you have a specific area to check. Try and bend the tyre outwards (not very clear, but I mean flex the tyre) as you examine it. I had a case where there were steel fibres from the tyre which were piercing the tube and causing punctures. These were invisible to the touch, except by flexing the tyre.

Also maybe check the inside of the rim isn't scored eg by a key or a fork when removing tyres. Although this is less likely when you seem to have the problem in the same position of the tyre on each wheel. Good luck.

kenmc

where is the puncture hole appearing? is it on the outside (nearest the road), the inside (nearest the spokes) or one of the sides?
Did you buy all your tubes in the same shop at the same time? Although I suppose it's unlikely that you have a bad batch of tubes...

PeadarofAodh

oobydooby wrote: »

When you're checking the tyre again for bits of glass etc. , as mentioned above you have a specific area to check. Try and bend the tyre outwards (not very clear, but I mean flex the tyre) as you examine it. I had a case where there were steel fibres from the tyre which were piercing the tube and causing punctures. These were invisible to the touch, except by flexing the tyre.

Also maybe check the inside of the rim isn't scored eg by a key or a fork when removing tyres. Although this is less likely when you seem to have the problem in the same position of the tyre on each wheel. Good luck.

+1 for the tyre flexing. I had a couple of mystery punctures myself and only found the tiniest sliver of glass embedded in the tyre when I flexed it.

blorg

pickarooney wrote: »

They're a little loose, although the tubes and tyres are both 700 diameter and the rim 23mm, tubes 19-23.

The tyre would be 23mm rather than the rim (it is almost certainly a bit narrower, although this is not as relevant, it is the tyre size that you match to the tube.) If you have 700x23 tyres (most standard road bike size) then 700x19-23 tubes should fit fine, I use this size myself.

You do know you need to slightly inflate the tyre before fitting it into the tyre and onto the rim- are you doing this? If so, it shouldn't be a bit loose. This will also help prevent pinching.

pickarooney

Holes vary from inside to side to outside. I'll have a closer look at the latest carnage tonight, see if there's anything new to report in terms of flexing the typre etc.

pickarooney

Nope, two more blow-outs in the meantime, each within 5km of changing tubes, both on the back wheel, still no sign of anything likely to have punctured it. I officially give up on the mystery and the bike.

i57dwun4yb1pt8

please dont take offense , im just curious , but are you a large person ? or carrying alot of bags etc ? if so , for puncture free commuting i would get a good mountain bike and semi slicks .

racer bike tyres have a very small foot print and are really meant for speed and not carrying too much weight . if enough weight is on the bike , you are grinding the tire into every piece of crap on the road , im 14 stone and carry about another stone in rucksack and the racer punctured all the time with that set up .

mountain bike and semi slicks stopped all that .

pickarooney

Not particularly - 80kg for 1m85, and I've only a light bag on my back. I probably will head into mountain-bike/hybrid territory though.

Raam

is it possible for you to try someone else's wheels?
Try and find a common denominator.

niceonetom

you haven't told us what tyres you're using and at what pressure. details?

btw, 8 bar is about right for most road tyres (23s) depending slightly on brand and your weight.

Seaswimmer

Just a thought. you mentioned you get a pair of tubes for €2.50. i have never come across a reasonable tube for this price - never mind 2.Buy the best tubes you can get. I am currently using Schwalbe 700 X 23 which cost €7.50 each. I think you can also get packs of 4 for about €20 in cyclesuperstore. A tube that costs €1.25 is going to be rubbish...

blorg

You could always try a new rear wheel before you give up on the road bike entirely.

pickarooney

niceonetom wrote: »

you haven't told us what tyres you're using and at what pressure. details?

btw, 8 bar is about right for most road tyres (23s) depending slightly on brand and your weight.

I don't know the exact name, they're Michelin tyres with red/black stripes, (allegedly) fairly puncture resistant. AFAICT there's nothing coming through them. The last few times I've been inflating to 8 bar.

Seaswimmer wrote: »

Just a thought. you mentioned you get a pair of tubes for €2.50. i have never come across a reasonable tube for this price - never mind 2.Buy the best tubes you can get. I am currently using Schwalbe 700 X 23 which cost €7.50 each. I think you can also get packs of 4 for about €20 in cyclesuperstore. A tube that costs €1.25 is going to be rubbish...

I'd be inclined to agree, in principle, although I don't really know how you could make a good or bad inner tube! It's just one ingredient. Then again, you could make a similar argument about condoms... The tubes in question are the generic 'blue label' tubes from a big French sports chain. Everyone buys them, but not everyone has my experience with them.

blorg wrote: »

You could always try a new rear wheel before you give up on the road bike entirely.

Already tried it. The back tyre went on the way home from the shop. The front tyre went three days later.