Toughest tubes?

[GrumpyGit]

I have another question for the assembled inteligencia.

Having already been reduced from having two bikes to just one as the Jack is away getting the duff wheel sorted, I got home from work tonight to find the back tyre on my hybrid was flat.

I pulled the wheel off and removed the tyre and tube. No punctures in the tyre, then I found the tube (original cheapo Chinese one that came with the bike) was split at the base of the valve. Chucked in a new tube (by a "quality" manufacturer) pumped it up to about 100 psi and was greeted by the sound of escaping air The tube was punctured on the inside face although I can find no sharp points to cause it. I've now fitted my last tube which seems to be holding air (fingers firmly crossed).

The question I have for you folks is this. Who makes the toughest, most puncture resistant tubes? These are for 700c x 38 size tyres. I'll be looking to buy some "bulletproof" Kevlar tyres in the spring.

[sham22]

I have exactly the same problem so watching replies with interest . Noticed piece of steel in tyre , removed it , replaced flat tube , new tube ripped immediately on inflation , removed that, flatted off the rim with wire wool to remove possible burrs on rim , second attempt failed too . Difficult replacing tyre at home , so god help on tour .

[julk]

When I commuted to work in Edinburgh I got the longest inflation times from my tubes when I put slime (or equivalent) in them.

It didn't stop things poking holes through the tubes, but it made a good attempt at delaying the loss of air through the smaller holes.

[GrumpyGit]

My last tube has gone flat as well. That's it, I'm down to no bikes! Just my Oyster card and Land Rover for transport.

The puncture is again on the inner face (i.e. towards the rim / spokes) but in a different location. All around the tube there are "pimples" which correspond with the spoke nipple locations. The rim tape is recessed into the spoke holes.

Is it possible that the original rim tape is too flimsy, allowing the tube to over expand and burst? If so, is it acceptable to add a second layer of rim tape to provide the tube with more support? Am I putting too much pressure in?

Back in the day when we ran tubed tyres on the Land Rovers we always rated the Michelin tubes as the toughest, combined with their 12 ply 750x16 tyres which were the only ones that wouldn't get punctured by African Acacia thorns!!

[Mick F]

The puncture is again on the inner face (i.e. towards the rim / spokes) but in a different location. All around the tube there are "pimples" which correspond with the spoke nipple locations. The rim tape is recessed into the spoke holes.

Is it possible that the original rim tape is too flimsy, allowing the tube to over expand and burst? If so, is it acceptable to add a second layer of rim tape to provide the tube with more support? Am I putting too much pressure in?

It may be that your rim tape isn't good, or even that your spokes are poking through. There's nothing stopping you putting on more rim tape.

Here's an idea: take off the rim tape, and wrap PVC insulation tape around the rim a couple or three revolutions, then replace your rim tape on top of it.

The tyre pressure should be as written on the side of the tyre.

[Steve]

Are your tubes the right size for the rim & tyre? If they're too small (narrow) they may be stretching too much & therefore prone to puncturing. It may be worth trying the next size up. But I have had the same problems with all sorts of tubes as well. Try fresh Schwalbe tubes if you can get them.

[appolo]

GG,in the past I've had to the same as Mick F suggests.But before doing so,took off all the rim tape and gently filed each spoke nipple end to remove any burs and scabby bits. (It took ages!) Have also found that on rims with recessed spoke holes, the edge of the holes themselves can often be sharp to the touch and if left, will eventually wear through the rim tape to puncture the tube. And as the old saying goes "you get what you pay for", it seems to happen more with cheaper rims. Hope this helps.

[GrumpyGit]

Are your tubes the right size for the rim & tyre? If they're too small (narrow) they may be stretching too much & therefore prone to puncturing. It may be worth trying the next size up. But I have had the same problems with all sorts of tubes as well. Try fresh Schwalbe tubes if you can get them.

I think you've hit the nail on the head Steve! I've been stewing on this one overnight. The tubes I was sold were 28/38, on inspection the originals were 35/43!!!

I'm off to a different bike shop later this morning to do some shopping, hopefully I should be mobile again by this evening. I'll double up on the rim tape too, just to be on the safe side.

Cheers

Derek

[MLJ]

As far as strength is concerned, I have found the normal Impac tubes very good and the valves fixed more securely than the Schwalbe ones, who make both types!

[wkb21]

Does anyone have any experience of this stuff with bikes? - -

http://www.oko.com/default.aspx?Element ... ticles#2.2

I note that it is used by bicycle distributors.

Any reports would be very welcome.

[PW]

Use cloth rim tape - Velox Fond De Jante (Jantex) will keep the tube away from the spoke ends. Schwalbe make good tubes.

[GrumpyGit]

Just wanted to say thanks for all the hints!

I'm mobile again, correct size tubes fitted with an extra layer of rim tape below. I've used the bike a couple of times this weekend and the back wheel is holding it's air again

Now if I can get my Jack back (from the same shop that sold me the wrong tubes) with a new front wheel I'll be a very happy boy, well not quite so grumpy, I do have standards to maintain

Cheers

Derek

[reohn2]

Derek
You mentioned in your first post that you inflated the tyre to 100psi,you don't mention what size tyre it was but as its a Hybrid I am assuming its between 28mm and 40mm,I've never needed to ride tyres of these sizes with more the 80psi(for 28mm)70psi(32mm) and 60psi(38mm).
On one of the tandems we ride 40mm marathons at 80psi and thats with 22st(143kgs) on board.I/we find anything over these pressures on bigger tyres just jiggle our/my eyeballs about or rattle our/my fillings out :0(

On the sharp edges front I find that the valve hole can be quite sharp so I 'soften' the edges with a bit of rolled up emery cloth and cut a piece of old innertube into a 25mm square make a hole in the middle and put it over the valve snug up against the tube for extra security.

Hope this helps.

[DaveP]

All around the tube there are "pimples" which correspond with the spoke nipple locations. The rim tape is recessed into the spoke holes.

This sounds very similiar to something that happened to me last year. In my case I simply increased my tyre pressure - still within the limits for the tyre! - and an hour later a wheel that hadnt punctured for months was flat. The tube had pimples as you describe and when I traced the leak it was from a tiny split around one of them.
The wheel had been supplied with rubber rim tapes. It appears that while these were ok in the distant past with protruding spoke heads, and the recent past with double skinned rims and pressures of 50psi or less thats about their limit.
I now use the Velox tape mentioned above. Thick and reassuring!

[GrumpyGit]

Derek
You mentioned in your first post that you inflated the tyre to 100psi,you don't mention what size tyre it was but as its a Hybrid I am assuming its between 28mm and 40mm,I've never needed to ride tyres of these sizes with more the 80psi(for 28mm)70psi(32mm) and 60psi(38mm).
On one of the tandems we ride 40mm marathons at 80psi and thats with 22st(143kgs) on board.I/we find anything over these pressures on bigger tyres just jiggle our/my eyeballs about or rattle our/my fillings out :0(

Hope this helps.

All interesting thoughts.

I did say they're 38's in the original post. As to the pressure, the gauge on my pump disagrees with the Raleigh branded handheld gauge I bought from a bike shop by at least 10 psi so I pump the tyres up until they're hard enough to withstand the crappy rough roads around here. The max shown on the tyre is 6 bar which is about 84 psi so it'll be there or thereabouts.

Some time I'll have to try out the gadget I've got to fill tyres off a scuba tank. Hmm 232 bar on tap, that's over 3000 psi!!!