Importance of Tyre Pressure

[MacB]

Why does an increase in tyre pressure create a reduction in riders output?

Discomfort causing fatigue and, on less than smooth surfaces, energy can be lost due to jolting around. In reality it's all fairly subjective as one persons ride comfort can be anothers torture. Stiff frame and rock hard tyres will feel faster but some claim the gains, if any, are pretty minimal, or at least for the average sort of rider. Then there's also the claim, more in relation to longer rides, that you will fatigue faster on the harsher ride and early performance gains will be lost, and some, in the closing miles.

You'll get people vehemently in both camps and can expect to hear, 'if it's what TdF riders do then it must be right'. The only way to be sure is to try for yourself and see how you feel, and what your computer says, at different tyre pressures and maybe sizes as well. Though a lot of road bike design limits what you can test tyre wise anyway.

 

[oliglynn]

Yup, you'd have to be a man of steel to get anywhere around 100 psi with a hand pump.

Another +1 for track pumps.

i know you can get mini pumps with a tube as well.

I got one of these Lezyne Road Drive pumps, and it's the best hand pump I've ever bought. They have tubes, and can get over 100psi in your tyres without too much sweat!

 

[arallsopp]

I've kept the Furai at 120psi for 2 years using the minimorph hand pump. I don't know that it reduces resistance in the real world (I'd wager it takes less energy to compress a tyre than it does to bump me and the bike an inch into the air) but it does keep the p*nc*ure fairy away.

Anything less than 100, and its snake bites on the front rim.

 

[GrasB]

Discomfort causing fatigue and, on less than smooth surfaces, energy can be lost due to jolting around.

Also your body simply keeping your muscles in the correct shape uses valuable power & energy when you're dealing with vibration, compression wear can help to some degree but not having to deal with these vibrations is a better option.

It's also subjective, I've consistently found that narrower 23c or 25c tyres are more comfortable & let me produce more power on a lot of the disintegrating tarmac than wider tyres as only one major component of vibration (vertical) which while larger in amplitude is easier to deal with than 2 major components (vertical & lateral). The whole shebang is to most people subjective (most people don't have a bike that can take the range of tyres & have a power meter to actually do properly comparative tests.

There are also other thing you can do to help keep the comfort level up, 26mm 'bars flex more at the stem so give a more comfortable ride than 31.8mm (OS) 'bars. I did a cheap v's expensive wheel set speed at a given HR test a while back where expensive more compliant wheels produced a small but noticeable speed increase, so the choice of wheels is also a factor.