Continental Supersonic Tubes - Am I a ham-fisted idiot?

Mr Will

Picked up a few of these to go with my new wheels are tyres (Pro-Lite Bracciano and Vittoria Open Corsa Evo CX II) but can't seem to get them to hold air.

Put them in, pump them up - all good. 5 minutes later while I'm putting my shoes on... PSSssssst. Fix the front one, go to put the wheel back on the bike and the rear one has done the same.

After about 6 attempts I managed to get them to work for a 5 minute ride around the block. Get home, taking shoes off. PSSSSSssssst.... PSSSSsssst. Off they go again. I gave up and fitted normal tubes at this point which have been fine since.

Now, is it something I'm doing wrong (likely) or might there be a bad batch? I've tried every fitting method I know to make sure they aren't getting pinched when putting them on. The tyres are very tight but I've still managed to get them on without levers and I've never had these problems before. It's also odd that they are going down with a hiss from a hole in the tube while the bike is just standing - not while they are being ridden or a bang while trying to inflate.

Any suggestions would be much appreciated!

drlodge

I'm using Supersonic tubes and had no problems at all. I pump them up a little - so they have a round shape - before fitting them under the tyre. That way they shouldn't pinch.

Where are the punctures/pinches you're getting? Are you sure its down to putting the tyre on?

Mr Will

Various points, so I don't think it's anything sharp inside the wheels/tyres. This is backed up by the fact that it's done it on both ends.

Tried putting air in before putting the tyre on (it's my normal method) - no difference. It was tricky to fit them this way though as they seemed too long for the wheel. Big gaps between tube and rim rather than sitting nicely against it like usually happens - very odd.

drlodge

Mr Will wrote:

Various points, so I don't think it's anything sharp inside the wheels/tyres. This is backed up by the fact that it's done it on both ends.

Tried putting air in before putting the tyre on (it's my normal method) - no difference. It was tricky to fit them this way though as they seemed too long for the wheel. Big gaps between tube and rim rather than sitting nicely against it like usually happens - very odd.

Sounds like the tube is over inflated as it will stretch in length and well as girth. I had this problem, just need to let out nearly all the air so the inner tube retains some shape - no more.

Mr Will

I worry that I have stretched them in the process - they seem a bit too long even when fully deflated.

desweller

So - where are the holes? When you say 'both ends' do you mean both wheels? Do you align the manufacturer logo on the tyre with the valve when you fit it so you can tell where the punctures are occurring?

I think I can guarantee that you haven't overstretched your inner tubes though.

pilot_pete

You have to be VERY careful fitting Supersonics. Do not use a tyre lever to get the last bit of tyre bead on, you can easily nip the tube. Also be very careful just rolling the last bit of tyre bead on with your thumbs, again it is very easy to pinch the tube against the rim with the tyre bead. Talc can help here to stop the friction between bead/ rim and tube.

Finally, put a little bit of air in, just one or two pumps of a track pump max....and even let a little out then to just make the tube take shape before fitting. Once the tyre is on, pump a few more pumps in, then work your way around both sides of the tyre pushing the bead away from the rim with your thumbs to see in the gap between bead and rim to ensure the tyre hasn't rolled over the tube and left a bit of tube between rim and bead (less likely if talced), which I have seen often with such thin tubes as Supersonics.

Once all this is done you can pump them up to full inflation and then hey behave like any other tube in my experience. I have nipped a few in the past and tend to carry heavier tubes as spares for changing whilst out, but use Supersonics fitted when at home.

It is usually nipping caused by using a tyre lever or by a very tight fitting tyre nipping the tube in the final few inches as you push really hard to get the bead over he rim.

PP

pilot_pete

Oh, and forgot to add,

If you leave Supersonics out of their box lying around, or especially in a small saddle pack rubbing against other tools, bits and bobs the can very easily get a small hole or two in them....this can happen with normal tubes in a saddle pack for months and months, hence why I wrap mine individually in lots of cling film. Even the valve can cause a hole when the tube is rolled up! Best to leave the plastic valve cap on when storing...

PP

Mr Will

DesWeller wrote:

So - where are the holes? When you say 'both ends' do you mean both wheels? Do you align the manufacturer logo on the tyre with the valve when you fit it so you can tell where the punctures are occurring?

I think I can guarantee that you haven't overstretched your inner tubes though.

Yes, both wheels and I do align the logo with the valve. Going to give it another go soon with a completely fresh tube now that the tyres have hopefully stretched and shaped a little with use.

pilot_pete

Give the tyres a VERY thorough inspection. I once got 3 punctures back to back, but over about an hour of riding. Each time I had run my fingers around the inside of the tyre and found nothing.

When I eventually got home I removed the tyre and only then did I find the smallest little shard of glass embedded in the tread. It was tiny and only by really rolling the tyre between thumb and forefinger (like making a roll up) did I manage to open the hole sufficiently to see it. Inside you couldn't feel it, but obviously when inflated and riding there was borderline enough pressure to eventually make it protrude enough to nick the tube.

Also, check your rim tape and spoke holes. A tiny burr of aluminium there can cause repeated punctures and a badly fitted rim tape can leave just the edge of a spoke hole exposed which is enough for the tube to rupture.

By the way, your tyres won't stretch if they are quality beaded tyres...

PP

Mr Will

Pilot Pete wrote:

Give the tyres a VERY thorough inspection. I once got 3 punctures back to back, but over about an hour of riding. Each time I had run my fingers around the inside of the tyre and found nothing.

When I eventually got home I removed the tyre and only then did I find the smallest little shard of glass embedded in the tread. It was tiny and only by really rolling the tyre between thumb and forefinger (like making a roll up) did I manage to open the hole sufficiently to see it. Inside you couldn't feel it, but obviously when inflated and riding there was borderline enough pressure to eventually make it protrude enough to nick the tube.

Also, check your rim tape and spoke holes. A tiny burr of aluminium there can cause repeated punctures and a badly fitted rim tape can leave just the edge of a spoke hole exposed which is enough for the tube to rupture.

By the way, your tyres won't stretch if they are quality beaded tyres...

PP

I strongly doubt there is anything sharp involved - the standard inner tubes have done about 100 miles now and are right as rain.

Perhaps stretch was the wrong word - I mean hold their shape better and go on and off a touch easier. Tyres are the folding kind and were repeatedly trying to return to their folded shape when I was trying to fit them!