driving me potty

cougie

Monty Dog wrote:

The debate on optimum tyre pressure continues to rage:

Increasing tyre pressure beyond about 7 bar has sod-all effect on rolling resistance unless you have the means to create a billiard-table smooth tarmac surface. It only feel like you're going faster - until you stop for a puncture that is.

Higher pressure give less grip and increases the likelihood or punctures from sharp debris - buying supple tyres and inflating them rock hard is pointless.

Those in the 'know' ride wider tyres and run then at 6 bar max and rarely puncture.

Soooo +1

kettrinboy

It looks like theres one group on here who think 100psi plus is best and another including me who go for sub 100psi, it may or may not have something to with that i use Conti Grand Prix 4000S tyres but ive never run the front over 80psi or the rear over 90psi and not had one puncture in 16000 miles, and i ride all year round on a lot of rough potholey roads, could be luck i suppose, i weigh 10.5 stone so i,m not super light either.

Headhuunter

kettrinboy wrote:

It looks like theres one group on here who think 100psi plus is best and another including me who go for sub 100psi, it may or may not have something to with that i use Conti Grand Prix 4000S tyres but ive never run the front over 80psi or the rear over 90psi and not had one puncture in 16000 miles, and i ride all year round on a lot of rough potholey roads, could be luck i suppose, i weigh 10.5 stone so i,m not super light either.

I think it also depends where your ride. I ride with up to 120psi in the tyres on all my bikes. Riding to work through London I get punctures (usually bits of glass). Riding on my club run bike through Kent I barely ever/never do. Both bikes have similar tyres.

Karl2010

kettrinboy wrote:

i weigh 10.5 stone so i,m not super light either.

HAHA. Either self concious about your weight or your bragging.
Im weighing in at about 13st '5lb at the moment. 6ft tall. All muscle mind you.

Obviously the more you weigh, the more pressure you need it the tyre. Probaly why im on 110psi.

benno68

Karl2010 wrote:

kettrinboy wrote:

i weigh 10.5 stone so i,m not super light either.

HAHA. Either self concious about your weight or your bragging.
Im weighing in at about 13st '5lb at the moment. 6ft tall. All muscle mind you.

Obviously the more you weigh, the more pressure you need it the tyre. Probaly why im on 110psi.

Nice one Karl2010 - I'm feeling more normal now weighing in at 13st and a bit (6ft), unfortunately I can't claim to it being all muscle .

I run mine at about 120psi.

ram038

thanks for the useful advice. I have order new tyres, vittorio rubino, have them on me old bicycle and rarely have a puncture, and rim tape

daviesee

kettrinboy wrote:

i weigh 10.5 stone so i,m not super light either.

I've not seen 10 1/2 stone since I was 15 and doubt I will see it again :oops:

Kind of explains why there is not a one size fits all answer.
I will still use a pressure somewhere within the manufacturer's recommendations though.

White Line

I don't get when people insist on running super high tyre pressures that I would only consider if I were a track rider. It's like it makes them feel manly. :roll:

I weigh in at a rather low 65 kg at a height of 6'. I've ran 100 psi rear and 90 psi front for quite a while now and I've not had a puncture since winter. As for pinch flats; I've had one but that was due to me being an absolute fandan and not looking where I was going.

I reckon I could get away with 90 psi rear and 80 psi front, but I see no need to try it and see. After all, if it ain't broken don't fix it.

Michelin seem to be saying this too. Plus, they know a lot about tyres.

antfly

Headhuunter wrote:

kettrinboy wrote:

It looks like theres one group on here who think 100psi plus is best and another including me who go for sub 100psi, it may or may not have something to with that i use Conti Grand Prix 4000S tyres but ive never run the front over 80psi or the rear over 90psi and not had one puncture in 16000 miles, and i ride all year round on a lot of rough potholey roads, could be luck i suppose, i weigh 10.5 stone so i,m not super light either.

I think it also depends where your ride. I ride with up to 120psi in the tyres on all my bikes. Riding to work through London I get punctures (usually bits of glass). Riding on my club run bike through Kent I barely ever/never do. Both bikes have similar tyres.

If you run them at 100psi you might find you get less punctures. I think if they are hard penetration is more likely to occur.

White Line

antfly wrote:

I think if they are hard penetration is more likely to occur.

:oops:

Headhuunter

antfly wrote:

Headhuunter wrote:

kettrinboy wrote:

It looks like theres one group on here who think 100psi plus is best and another including me who go for sub 100psi, it may or may not have something to with that i use Conti Grand Prix 4000S tyres but ive never run the front over 80psi or the rear over 90psi and not had one puncture in 16000 miles, and i ride all year round on a lot of rough potholey roads, could be luck i suppose, i weigh 10.5 stone so i,m not super light either.

I think it also depends where your ride. I ride with up to 120psi in the tyres on all my bikes. Riding to work through London I get punctures (usually bits of glass). Riding on my club run bike through Kent I barely ever/never do. Both bikes have similar tyres.

If you run them at 100psi you might find you get less punctures. I think if they are hard penetration is more likely to occur.

I think the theory goes that the harder the tyre, the more likely the offending sharp item is to be crushed or flicked away. At lower pressures a shard of glass or whatever can push through more easily. I've certainly never heard anyone other than people on here claim that lower pressures = fewer punctures, it's kind of accepted logic that the higher the pressure the fewer the punctures. Unless you're claiming that this only works up to 100psi but I've certainly never heard that before. My example above was to demonstrate that puncture frequency is more a product of where you cycle than anything else. I ride all my bikes at about 100-120psi and out in teh country I get no punctures to speak of but in London where there is more detritus on the roads I get them. At the same pressure.

daviesee

The OP uses Continental Ultrasports.
According to Continental the recommended pressures are:-
23mm - 110psi
25mm - 95psi
28mm - 80psi
32mm - 70psi

Continental should know a thing or two about their tyres.
Can we please move on?
I have now......

antfly

Headhuunter wrote:

antfly wrote:

Headhuunter wrote:

kettrinboy wrote:

It looks like theres one group on here who think 100psi plus is best and another including me who go for sub 100psi, it may or may not have something to with that i use Conti Grand Prix 4000S tyres but ive never run the front over 80psi or the rear over 90psi and not had one puncture in 16000 miles, and i ride all year round on a lot of rough potholey roads, could be luck i suppose, i weigh 10.5 stone so i,m not super light either.

I think it also depends where your ride. I ride with up to 120psi in the tyres on all my bikes. Riding to work through London I get punctures (usually bits of glass). Riding on my club run bike through Kent I barely ever/never do. Both bikes have similar tyres.

If you run them at 100psi you might find you get less punctures. I think if they are hard penetration is more likely to occur.

I think the theory goes that the harder the tyre, the more likely the offending sharp item is to be crushed or flicked away. At lower pressures a shard of glass or whatever can push through more easily. I've certainly never heard anyone other than people on here claim that lower pressures = fewer punctures, it's kind of accepted logic that the higher the pressure the fewer the punctures. Unless you're claiming that this only works up to 100psi but I've certainly never heard that before. My example above was to demonstrate that puncture frequency is more a product of where you cycle than anything else. I ride all my bikes at about 100-120psi and out in teh country I get no punctures to speak of but in London where there is more detritus on the roads I get them. At the same pressure.

I just thought If you are getting flats anyway, in London, it might be worth experimenting with lower pressures. 120psi is very hard and 100psi is more comfortable and more grippy as well. You could be a test case.

Andywyre

I'm shocked all these answers and no one has mentioned tpi

Tyre pressure based on tyre plus your weight, but i agree 100-130psi

Now when buying tyres the higher the tpi the more threads in the surface, the more threads the denser the surface and therefore generally more puncture resistant
Look for a 170tpi

In the old days when we had a punture we used to fill the tyre with grass to get home, you could always try that.