wrong inner tube size effects?

MDobs

Trying some low volume 1.8 tyres for the wet/mud and switching them over just realised that my tubes are 2.1-2.5 sized.

What's the likely effect of running the tyres with these tubes?

I'm worried they'll be prone to punctures or not support the tyre properly, or am i just being paranoid (the switch from 2.25/2.35 tyres to 1.8 is quite dramatic!).

Chunkers1980

Not a lot, just more weight than is needed.

The Rookie

More weight and you risk pinching a tube between tyre and rim during fitment which will (usually at the worst time) eventually puncture the tube.

I run undersized tubes to save weight and use 1.0-1.5 tubes inside tyres upto 2.3"

MDobs

ok, that's fine, i don't mind about the weight at the moment, i'll switch them for smaller tubes when i get the chance but i'll use them for the moment. I don't think i've pinched them whilst fitting, was quite careful about that.

Cheers for the responses.

ricardo_smooth

The Beginner wrote:

I run undersized tubes to save weight

Is this a real reason.......what's the weight difference Vs the tube that's the 'correct' size?

Chunkers1980

Can be 50grams. Pay for that in the rim and that'll cost quite a lot.

ricardo_smooth

Can be? Comparing what sizes?

Chunkers1980

Makes and same tubes can differ too, it's a case of getting the scales out I'm afraid

The Rookie

Schwalbe and Geax (and others I'm sure) put the weights on the website, an average MTB tube is about 200g, most manufacturers do lightweights for a bit more money that come in at around 120g, or I get the smaller size which are easier to carry and fit and logically the same thickness inflated as they weigh similar.