TPU inner tubes

[Pblakeney]

If you are still putting 100psi into tyres what is the total system weight and tyre size? 100psi seems pretty high these days.

It was always the appropriate pressure, and always will be.
25mm.

 

[SWMc]

Question : Do TPU Tubes loose air faster than butyl tubes, and if so does 2-weeks suggest a micro hole?
(Have checked valve and it’s secure)

Yes, faster than butyl tubes, maybe 15psi loss (from ~80 psi) in a week. I've not had one go completely flat while in the garage though even after a month, maybe you have a dodgy valve or the area around the valve seems to be a common leak path.

 

[Cycling Badger]

Yes, faster than butyl tubes, maybe 15psi loss (from ~80 psi) in a week. I've not had one go completely flat while in the garage though even after a month, maybe you have a dodgy valve or the area around the valve seems to be a common leak path.

Thanks - the tyre was probably around 45 PSI and was flat enough that I could see tyre was flat. So I _guess_ it was down at 10 PSI or less. Must be a very slow puncture. Bloody annoying as I‘ve rode on it twice and it was expensive - won’t be buying another one :-(

 

[Binky]

Thanks - the tyre was probably around 45 PSI and was flat enough that I could see tyre was flat. So I _guess_ it was down at 10 PSI or less. Must be a very slow puncture. Bloody annoying as I‘ve rode on it twice and it was expensive - won’t be buying another one :-(

Patch it? I had a thorn puncture and I put an instant TPU patch on and it held pressure no leaks for 6 hours so I'll carry it as a spare and I'm confident it's good to use.

 

[Poacher]

The bit that catches people out with roadside TPU repairs is that ordinary rubber solution won't touch it — the vulcanising glue in a normal puncture kit bonds to butyl, not to the polyurethane, so it just peels. You need the TPU-specific self-adhesive patches (the ones that come with the tubes) or a proper polyurethane glue, and even then the surface has to be genuinely clean and dry, which is the hard part at the side of a road in the wet.

So realistically it matches what you're all finding: a patched TPU tube is a get-home fix, not a permanent one. I treat any TPU tube I've patched as a bin-it-after-this-ride job. The insulation-tape trick can hold air for a bit, but I wouldn't set off on a fresh ride trusting it either.

What I've settled on is carrying one spare TPU tube for the weight and pack-size win, plus a single cheap butyl tube as the ultimate backup. If it turns into one of those days with multiple punctures, butyl you can always patch conventionally and actually trust. Barely any weight penalty and it takes the worry out of it.

Butyl is in the eye of the beholder.
I'll get my coat.

 

[Dirk Van Der Dirk]

Butyl is in the eye of the beholder.
I'll get my coat.

You have set a low bar for jokes. I'd stay sealant from here on in if I were you.

 

[Webbo2]

You have set a low bar for jokes. I'd stay sealant from here on in if I were you.

His lips are sealed.

 

[Dirk Van Der Dirk]

His lips are sealed.

Hopefully they think before they presta 'post reply' button next time

 

[Poacher]

You have set a low bar for jokes. I'd stay sealant from here on in if I were you.

Well, I Woods, but I feel under pressure to MilKit for all it's worth. Sorry to be such a Big Bore.

 

[Webbo2]

Well, I Woods, but I feel under pressure to MilKit for all it's worth. Sorry to be such a Big Bore.

You just need to plug it mate.

 

[Dirk Van Der Dirk]

Well, I Woods, but I feel under pressure to MilKit for all it's worth. Sorry to be such a Big Bore.

It's all good mate, no need to feel deflated.