Foss "super" inner tubes

I was racing last night, and because the race wheels are retained centrally for major events this year, I was racing on 'training wheels' which run Conti GP4000s tyres and standard tubes. I happened to throw a leg over a bike running decent tubs, and the difference was obvious.

Indeed when I throw a leg over my bike with race wheels in, the difference is clear... never underestimate the difference good rubber can make to the feel of a bike.

Now, what that difference equates to in real speed is hard to say without doing some proper tests, but it does feel better.

Saying that, if you run a decent set of racing tubs on a set of resistance rollers, you do go noticeably quicker than on a set of standard clinchers and tubes.

It depends on the tyre - latex tubes under a bit of garden hose won't matter a jot - but on a super supple tyre, they do.

compliant? I've always wondered about these claims made on inner tubes and their effect on ride quality. I've never ridden on latex tubes, but i don't believe for one second that they make a perceptible or measurable difference to ride quality.

I've used them... And I think they are pretty good puncture wise... And a good option for training

One downside of these is once they are used they stretch. So if you change your tire, its difficult to re-use the tube..

I also think they are not as compliant as a normal tube... So the ride is not as good.

I don't know about the puncture resistance claim but 103g isn't especially light for road tubes - standard road tubes like Schwalbe SV15, Conti Race Light 28 etc are 100~110g. Michelin Aircomp Ultralight and Schwalbe SV20 are about 75g.