rockstar wrote:fde, i'm guessing you're riding tubbies? what s your weight, and tire pressure preference?
thanks,
Hi,
You're quite correct, I prefer riding tubulars over clinchers. If we stick with the common 23mm sized tyre or tubular I usually put in 7,5 bar (~95 PSI) for the front, 8 bar (~110PSI) max. for the rear.
I currentyl weigh 70 kgs (~145 lbs).
People tend to overinflate as most of the time they either think higher pressure's better or they simply read the max. allowed pressure from the the tyre wall and apply just that.
For rough roads I always use less pressure, smooth roads will see the figures as stated above.
@Alienator: RR figures are derived from lab measurements and those are almost invariably done on smooth surfaced drums. If we'd stick with that we all know what we talk about.
You'll also need to know at what pressure those figures were derived at so when two different tyres are compared you should ideally compare them under equal conditions or you're just comparing apples to oranges.
On roads it's not the rolling resistance of the tyre that changes but it's the efficiency of transmission that gets lost when tyres are overinflated due to loss of adherence to the underlaying surface. Pretty simple to understand, really.....
IOW, no point in having ultra low RR figures in the lab when you can't put it to good use under practical circumstances, right?
Very well made tubulars can actually handle higher pressure and still conform to road surfaces better than most clinchers while still being comfortable.
Put differently, this tubular will both roll better and be more efficient even if it's measured RR in the lab would be inferior.
It will also retain all the other inherent benefits that just come with the superior engineering of the design of a tubular. Something you just can't port over to a clincher no matter how well it's made.
Ciao,
