Importance of Tyre Pressure

[User]

 

[Paul_L]

interesting.

I set a commute to work PB last week along the tow path, the morning after pumping my tyres upto their max of 80psi.

So, better performance and better p***ure resistance.

 

[snorri]

Interesting figures indeed, my track pump is the best cycling accessory I have ever purchased.
Could it be that the message hidden within your Table of Results, spells out Retired Gentleman?

 

[RichardWHardwick]

Maybe I'm weak but I can't seem to pump my tyres up full with the pump I got free from the bike shop when I bought my bike.
Maybe I should be purchasing yet another thing?
Just got to work out how to get it past the wife
Does it really make that much difference?

 

[GrasB]

Roll out tests are only half the party though, you also need to know how fatiguing the higher pressure is. 100psi is a higher pressure than I run my 700x23 & 650x23c tyres, while higher pressures result in better roll out results the actual power I put into the rear wheel reduces dramatically on medium to rough tarmac & increases fatigue levels a fair bit resulting in much reduced average speeds.

 

[4F]

Just got to work out how to get it past the wife
Does it really make that much difference?

Get it delivered to work

and yes it does make that much difference

£ 20 on decent track pump is well worth it

 

[twozeronine]

Maybe I'm weak but I can't seem to pump my tyres up full with the pump I got free from the bike shop when I bought my bike.
Maybe I should be purchasing yet another thing?
Just got to work out how to get it past the wife
Does it really make that much difference?

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.

 

[cyberknight]

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.

+2 ...

And a Topeak road morph for the bike as well, i just cant get enough pressure into my tyres with a standard mini pump, i do run at 110 psi though..

 

[Bicycle]

As ar as I can tell, pressure has an enormous effect.

I run road bike tyres (700c 23) at 110 to 115. That helps me whizz along with reasonable ease.

Although I'm sure the effect is mostly psychological, I drop pressures to around 95 in wet or slippery conditions.

If I set out at 115 and it gets very wet, I begin to get illogically nervous... I wish I didn't.

It's worth noting that (unlike car and motorcycle tyres) bicycle tyres can lose pressure pretty rapidly. You need to check them pretty frequently.

On an MTB I run slick Contis at 80 psi for road use (huge fun on the streets of London). I do those with the gauge on a track pump. But... I never use a gauge on my knobblies if going off-road.

I just squeeze off-road tyres and go on that basis. I have no idea even what the ballpark figure is...

My usual fave pressure for off-road is technically known as: "Sort of a little bit hard to squeeze but you can make a small indent, but your thumb aches a bit".

I go softer sometimes depending on trail and conditions. It's all strictly XC for me, so no leaping off things.

Friends take MTB pressures really seriously, but I find that if they're quite hard to squeeze I don't get snakebites... and if I can squeeze them I do.

Am I the only idiot, or do other folk have strict pressure figures for one discipline and just a squeeze and a shrug for another?

 

[dave_79]

i am really intrigued about tyre pressure now. Forgive the stupid question but all this track pump lark is new to me so i really have no idea..........i presume track pumps are more beneficial to those wanting around the 100 mark, if my tyres are only needing 50 is a track pump still necessary, or more so that its just handy for giving you a pressure reading?

 

[cyberknight]

i am really intrigued about tyre pressure now. Forgive the stupid question but all this track pump lark is new to me so i really have no idea..........i presume track pumps are more beneficial to those wanting around the 100 mark, if my tyres are only needing 50 is a track pump still necessary, or more so that its just handy for giving you a pressure reading?

A lot less effort as it has a bigger barrel and you can get your bodyweight over the handle so it you can pump harder.
A lot of the mini pumps connect straight over the valve and can be a swine to hold on while you are pumping, even bending the valve in the process.

A track pump has a tube that is flexible so you are not putting twisting forces on the valve, i know you can get mini pumps with a tube as well.

 

[twozeronine]

i am really intrigued about tyre pressure now. Forgive the stupid question but all this track pump lark is new to me so i really have no idea..........i presume track pumps are more beneficial to those wanting around the 100 mark, if my tyres are only needing 50 is a track pump still necessary, or more so that its just handy for giving you a pressure reading?

Well, for road tyres you typically want about 100-120 psi, so to achieve that you need a track pump. If you don't have any problem filling your tyres to full pressure with a hand pump, then you don't really need one. However, if you did have one you'd be able to pump it up in no time at all.

 

[DuncanBeaumont]

My last pump has become more and more useless, to the point where I have invested in a proper track pump with pressure gauge, what a huge difference it makes getting the pressure up.

Have tried to quantify it below. Tyres are 28mm Armadillos. 50psi was all my old pump was achieving and 100psi is the max rated on my tyres. My test run was freewheeling down a slight hill for about 300 metres followed by a very slight incline. The distance in my table was how far the bike would roll from the bottom of the hill (cut off point was when speed fell below 5mph)

Not much difference in max speed but 11% increase on distance was very interesting.
Off course the big difference is how much easier it all feels.

Does anyone have any proper scientifically done data on tyre widths / pressue etc etc.

 

[DuncanBeaumont]

I found a similar effect. I changed MTB tyres 1.95 for slicker 1.5 and found my speed freewheeling was greater and distance was MUCH further, see the link.

https://www.cyclechat.net/

 

[GrasB]

Roll out tests are only half the party though, you also need to know how fatiguing the higher pressure is. 100psi is a higher pressure than I run my 700x23 & 650x23c tyres, while higher pressures result in better roll out results the actual power I put into the rear wheel reduces dramatically on medium to rough tarmac & increases fatigue levels a fair bit resulting in much reduced average speeds.

So we could be talking different optimum pressures for different road surfaces? Could get very complicated.

Say you reduce the rolling resistance at 20mph by 1w but reduce the riders power output by 10w you have a net reduction in speed. IME this is what happens when you inflate the tyre to the pressure which gives the maximum roll out distance.