Schwalbe SV20 inners, BOTH blew out within 5 mins!!!

adamdavi3s

Hi All,

I fitted Schwalbe SV20 to my road build and within 5 mins of being used, BOTH blew out.... and I mean gunshot loud blew out!

I've NEVER had a blowout before so can't imagine how I installed them wrong, the cheap conties I fitted to replace them performed flawlessly...

Prior to even using these I had to send one back due to a dodgy valve, I'd just expected better from a £9 innertube!!

Are they just crap or is this something I've done wrong somehow?

ride_whenever

You've almost certainly pinched them during fitting. Such very thin tubes are very delicate until fitted.

If these were in old tyres it could possibly be detritus that wouldn't touch a thicker tube but easily defeat the thinner 20's.

I've not had any issues with the schwalbe lightweight tubes personally, even in 20mm pro3

adamdavi3s

Hmm I did take a LOT of care in installing them.
Brand new RS80's and brand new ultremo R1's so hopefully its not anything to do with those

AndyOgy

Check the rim tape. If you've got plastic or a rubber band type thing, remove it and get some Velox cloth rim tape.

Also, what ride_whenever said.

Pokerface

Why would you pay £9 for innertubes? :shock:

adamdavi3s

It was a new build so I was just going for everything as light as possible!
Needless to say after that failed little experiment I'll take the 100g hit and stick with my good old £2.50 contis!!!!

giant_man

I use SV15 Schwalbe and never had any problems so must be the way you're fitting them.

balthazar

There is no kind of inner tube failure that can result in an explosive blow-out. That is always a clinching failure, which allowed the inner tube to escape the tyre. Any other tube would have done the same.

The usual cause of a clinching failure is inner tube trapped between the tyre bead and the rim. It's a little easier to do (and not notice) with thinner tubes, but otherwise you should take care to seat the tyre bead very carefully, as your tubes are not to blame.

adamdavi3s

Yeah I guess I must have fitted them incorrectly. it just surprised me that they both gave out having never had a pinch flat (but plenty of glass / thorn based flats) in the last 5 years, even using the exact same tyre and wheel combination!
I wondered if they were notorious for it.

Ahh well, I'm happy with my trusty continentals at 1/4 the price so its no big deal!

ADIHEAD

If you want a light set of tubes, I've had my Michelin Latex tubes in my best set of wheels for over a year now 3 sets of tyres, same tubes. Admittedly I chuck tyres as soon as they look worn but have seen some sizeable cuts in the tyres and no p&^$es

white91

I have had the exact same thing happen! One blew out before I got on the bike, and other blew out whilst on a ride!

I was very careful fitting, and also fitted brand new Ultremo ZXs. I think these are simply too light? I will stick with Continentals, as a blow out is scary.

sungod

light tubes are much easier to trap between bead and rim than normal weight ones, after which it's just a matter of time before the bang

inflate the tube until it is firm (but not bulging!), then fit it

doing it this way is far less likely to result in the tube being caught