Tubed V Tubeless

[Matthews]

Re:

Said it before and will make no doubt say it again but high pressure on knobbly tyres is less efficient and uses more energy (harder work in the real world) than low pressures as you have to ride up every knobble so it's like riding uphill on the flat .

 

[tufty]

Re: Re:

Said it before and will make no doubt say it again but high pressure on knobbly tyres is less efficient and uses more energy (harder work in the real world) than low pressures as you have to ride up every knobble so it's like riding uphill on the flat .

Science says otherwise.

For example, from http://www.bicyclerollingresistance.com

For a Nobby Nic Snakeskin 2015, rolling resistance @ 29 km/h with a load of 42.5 kg

55 psi 20.3 Watts
45 psi 21.0 Watts
35 psi 22.4 Watts
25 psi 25.0 Watts

So at 25psi, you need to put in 1/4 as much power again as at 55psi just to maintain the same speed. And the Nobby Nics come out really well compared to some others.

Or maybe, http://www.singletracks.com/blog/mtb-tr ... -pressure/, which shows rolling resistance going up in a more or less linear fashion as pressures go down to 20psi, and then going up massively afterwards.

 

[mattr]

All bicycle tires are tested on a rolling resistance test machine with a 77 cm drum and a 120W electric motor. The drum is covered with diamond plate to simulate an average road surface.

so completely representative of the average dirt track then?

 

[mattr]

http://www.schwalbetires.com/wider_faster_page

Real world testing.

 

[tufty]

OK, that's an interesting read. Full(er) version here - http://www.mtbonline.co.za/downloads/Ro ... trated.pdf