Tyre Pressure

Anonymous

I was just wondering what pressure I should have my Tyres at?

Have just fitted Vittoria Rubinos just till the roads clear up. What pressure is optimal for tyres, The Highest pressure stated, 10psi less? or no set rules? Also for a heavier rider should my pressures be higher or lower to help with body weight issues?

Thanks all

keef66

The pressure on the tyre is generally the maximum. I usually run as low a pressure as I can get away with while avoiding pinch flats. For me on 25mm tyres it's about 90psi rear, 80psi front. Heavier rider = higher pressure.

Some people like to use 110 psi all the time; that would shake my fillings out.

terongi

Yes, it's all about compromise.

Maximum pressure: Better rolling resistance therefore faster in the short term, but ...

...much less comfort therefore slower in the long term because you fatigue more quickly when you are less comfortable

Lower pressure: Statisticallly more chance of a puncture because you are presenting more surface area to the ground where all the little sharp things are. Pinch flats are an additional problem at even lower pressures, but...

...better grip in the wet and on slippery/loose terrain because more of the surface area of the tyre is in contact with the road where all the grippy friction is.

In very simplistic terms, you can have either:

(a) a grippy comfortable ride with more punctures (lower pressure)
(b) a high speed uncomfortable ride with fewer punctures but greater risks on dodgy surfaces (higher pressure)

So I use different pressures for different types of riding

eg maximum pressure for short road race on a dry day
lower pressure for long training ride or sportif in the wet

gtitim

with pot holes springing up all over the place, definitely dont run them too high. 90 sounds about right to me.

redddraggon

terongi wrote:

(a) a grippy comfortable ride with more punctures (lower pressure)
(b) a high speed uncomfortable ride with fewer punctures but greater risks on dodgy surfaces (higher pressure)

In my experience you less likely to puncture with lower pressures.

teagar

Between 6 & 7 Bar is fine. Anything over is counter-productive.

Most Tour riders ride 6 bar in the wet apparantly.

hopper1

gtitim wrote:

with pot holes springing up all over the place, definitely dont run them too high. 90 sounds about right to me.

Don't run them too low... Potholes = Pinch flats!

hopper1

teagar wrote:

Between 6 & 7 Bar is fine. Anything over is counter-productive.

Most Tour riders ride 6 bar in the wet apparantly.

88 - 103psi in old money!

teagar

hopper1 wrote:

teagar wrote:

Between 6 & 7 Bar is fine. Anything over is counter-productive.

Most Tour riders ride 6 bar in the wet apparantly.

88 - 103psi in old money!

You the same guy who patronised me about typing English without a capital? :roll:

You'll be hard pressed to buy a pump which doesn't have BAR on it.

Anonymous

Thanks all, guess I will try 90 psi/6 Bar and see how it goes. New tyres, bike and 95kg road rookie on very ancient pot holed roads = very nervous rider :oops:

Infamous

120 psi once or twice a week.

Anonymous

14.74 psi to 1 bar.

STEFANOS4784

teagar wrote:

hopper1 wrote:

teagar wrote:

Between 6 & 7 Bar is fine. Anything over is counter-productive.

Most Tour riders ride 6 bar in the wet apparantly.

88 - 103psi in old money!

You the same guy who patronised me about typing English without a capital? :roll:

You'll be hard pressed to buy a pump which doesn't have BAR on it.

But PSI is more accurate, same reason inches and feet aren't really used anymore, somone coming into the shop saying 9ft by 12 ft can cause problems, due to the discrepancies IME, more accurate the better IMO :arrow:

Monty Dog

redddraggon wrote:

terongi wrote:

(a) a grippy comfortable ride with more punctures (lower pressure)
(b) a high speed uncomfortable ride with fewer punctures but greater risks on dodgy surfaces (higher pressure)

In my experience you less likely to puncture with lower pressures.

Agreed, and likewise higher pressure doesn't equal reduced rolling resistance because the determinant factor is the road surface

Stone Glider

But isn't rolling resistance to do with the effort required to deflect the tyre to a flat contact with the road? Therefore a higher pressure could result in an increase in resistance :?

Anywho, the softer the tyre the more comfortable the ride, as has already been said. Pinch flats should really be a problem for heavier riders, not 70kK greyhounds (I wish). High tyre pressures seems to be a machismo thing. Anyone who has tried to puncture a half-inflated balloon should challenge the notion that high pressure = puncture resistance.

Edit: rolling along on the rims is not recomended.

cougie

I used to ride at the higher pressures 140 psi on vredesteins, and higher on tubs - thinking more is better.

A Continental Tyres mechanic told me to run them at 90 or so - and its been so much better.
Conti GP4000S are incredibly resistant to flats.

If you do ride tyres at the max - they bounce on the road - they arent faster plus its a harsh ride.

Anonymous

I have just removed my Conti GP4000s tyres, only used them on 2 runs but figure I will keep them for Spring/Summer and use the Rubino rigids that came with the bike for the rest of winter. I will set them at 90psi for my ride tomorrow and see how it goes.

sampras38

thunderflash55 wrote:

I have just removed my Conti GP4000s tyres, only used them on 2 runs but figure I will keep them for Spring/Summer and use the Rubino rigids that came with the bike for the rest of winter. I will set them at 90psi for my ride tomorrow and see how it goes.

Tomorrow or sunday I think I'm going to try 100 on the back and 90 on the front with my Vittoria Rubino's. Sunday's supposed to be wet apparently.

keef66

Looks like Sat is a washout but Sunday looks nice.

sampras38

keef66 wrote:

Looks like Sat is a washout but Sunday looks nice.

Yeah, sorry, I mean't Sat is wet..;-)

cyberknight

Yup i normally find 90 psi a nice compromise , over a hundred and my hands are numb.

Mind you i am running an ali fork so if some kind rich person has a carbon fork spare ...

oldwelshman

I normally run 100psi until summer when I put a bit more in but to be honest you lot must have sensative hands and arses becuase I cannot feel the difference
As for rolling resistance, it makes no difference between 90 and 150. Years ago it was always believed thinner tyres and higher pressures reduced rolling resistance but no evidence to support it, infact seen some to contradict it.
As for pressure affecting punctures, I believe it is pure luck with pinch punctures and do not think 10 psi either way makes a difference hit a pothole right and you will puncture whatever the pressure.
Anyway if you put 90 in, it is probably 85 with leakage taking valve off.

cougie

A combination of Conti GP4000S tyres and lower pressure is working really well for me. I cant remember the last time I punctured on the road. And its usually thorns rather than potholes - havent had a snakebite flat for decades.

Just wish my MTB tyres were as hardy !

John.T

cougie wrote:

A combination of Conti GP4000S tyres and lower pressure is working really well for me. I cant remember the last time I punctured on the road. And its usually thorns rather than potholes - havent had a snakebite flat for decades.

Just wish my MTB tyres were as hardy !

Thats you doomed then.

ChrisFilter

oldwelshman wrote:

I normally run 100psi until summer when I put a bit more in but to be honest you lot must have sensative hands and arses becuase I cannot feel the difference

Yeah, this. I tend to go for 110psi, but then I weight 15st.

mattward1979

I go 110 rear 100 front... 16.5 stone, at 90 im sure id get having snakebites every mile.

joshtp

this thread makes me laugh, i run 25psi, and never, ever have a puncture, even less often get snakebites, and i ride very aggresively in the city, and off road, i regularliy hit kerbs hard, and pound rocks....

the marvel that is a 850g 2.5 DH mtb tyre... and 200g fat tubes....

ChrisFilter

joshtp/mbukman wrote:

this thread makes me laugh, i run 25psi, and never, ever have a puncture, even less often get snakebites, and i ride very aggresively in the city, and off road, i regularliy hit kerbs hard, and pound rocks....

the marvel that is a 850g 2.5 DH mtb tyre... and 200g fat tubes....

This is because mtb tyres/tubes are very different from road. It's like comparing formula 1 tyres with lorry tyres.

joshtp

ChrisFilter wrote:

joshtp/mbukman wrote:

this thread makes me laugh, i run 25psi, and never, ever have a puncture, even less often get snakebites, and i ride very aggresively in the city, and off road, i regularliy hit kerbs hard, and pound rocks....

the marvel that is a 850g 2.5 DH mtb tyre... and 200g fat tubes....

This is because mtb tyres/tubes are very different from road. It's like comparing formula 1 tyres with lorry tyres.

yeah, i know, i realise the diference, i still find it funny though, i mean, 100psi!?!?!? are you seriouse?

Anonymous

I have Pro-Lite Luciano wheels, was checking out the their website and there is something about tyre pressure and their wheels

"Don’t let famous brand of wheels or tyres tell you that you might feel you are going fast but actually the vibration will wear you down and sap your energy. This could only be written by people who have never actually raced as pro and had to pedal tens of thousands of
kilometres to get a pay cheque each month.

So we recommend you buy the best tyres you can afford and pump them up hard. Even on our test bikes we will fit cheap tyres that say 110 psi max pressure. We always pump them up to 150 psi minimum without problems."

Can this be right? Safe?

Stone Glider

@TF55 That must be the most astounding piece of B/S I have seen on a forum site. Believe me I've seen a few. The wonderful world of cycling (TM) does have ait's fair share of nutters. Thanks for the quote.