Need advice on 23c Tyre pressure !

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atlantis

Well-Known Member
Hi!

I need some advice regarding my problem mentioned down below:-

Tires Hutchinson Equinox
Size 650 x 23c
Presta
Recommended Air pressure 100 psi
Maximum Air pressure 110 psi

I just ordered for a new pump with gauge and unknowingly filled in 140 psi in both the tires. Within 10 minutes I realized my mistake.

I have not ridden the bike with the incorrect tire pressure !

I immediately deflated both the tires to the correct pressure.

My question is :

1. Have I any way damaged the tire or tube ?

2. Have I damaged the rim ?

Your advice would really be appreciated.

rgds
 
OP
OP
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atlantis

Well-Known Member
Thanks for the reply !

I really do not wish to repeat this mistake. But just for the sake of knowledge : if unladen pressure in the tyre is 110psi then "What would the approx pressure in the tyre, increase to--- if a 165 pound person is astride.
 

corshamjim

New Member
Location
Corsham
btw, please don't try inflating your tyres to double the rated pressure without consideration of your safety. I would at least wear some tough eye protection, and have some idea where the pump hose is going to go if it blows off the wheel!

I don't think the pressure increases hardly at all with a 165 pound person on board. All that happens is that the area of the contact patch with the ground increases in size. If the rider's weight is evenly distributed across both front and rear wheels and the bike weighs 35 pounds, then there will be 100 pounds weight on each wheel so the contact patch will be just under one square inch in size. To double the contact patch to 2 square inches you would need to increase the weight of the rider by more than 200 pounds!

All that is theoretical of course - no doubt the strength of the sidewall has some effect and of course the riders weight is rarely going to be evenly distributed front/rear.
 

swee'pea99

Squire
Incidentally, regardless of what it says on the tyres, the best pressures to use are 120 rear and 100 front. Gives a fast ride and protects against You Know Who.
 

MacB

Lover of things that come in 3's
[quote name='swee'pea99' timestamp='1309250508' post='1725166']
Incidentally, regardless of what it says on the tyres, the best pressures to use are 120 rear and 100 front. Gives a fast ride and protects against You Know Who.
[/quote]

What????? sorry but that's utter garbage, no allowance for rider/bike weight then? and the word is puncture there's no such thing as fairies
 

zexel

Veteran
Location
Cambs
[quote name='swee'pea99' timestamp='1309250508' post='1725166']
Incidentally, regardless of what it says on the tyres, the best pressures to use are 120 rear and 100 front. Gives a fast ride and protects against You Know Who.
[/quote]

"Best" for what?:wacko:

Taken from a tyre makers site: It is impossible to make a general recommendation on inflation pressure for a specific bike and rider, the right inflation pressure depends on too many variables.
Frame and wheel material, construction and stiffness of these, weight distribution, asphalt surface, width and material of tires and tubes, weather and temperature, and not least riding style are the most important variables to find which is the right inflation pressure.
 

MacB

Lover of things that come in 3's
For road, this is the single best article I have seen.

very interesting and quite a difference front and rear, or at least for the heavier rider :blush: you have to be pretty heavy to warrant as much as 100psi in a front tyre, even at 23mm size. According to my reading of the chart you need 100lbs up front to justify this, which means you, and bike, would need to weigh in around the 250lbs mark. Assuming a bike weight of no more than 30lbs that would mean you need to be North of 15.5 stone to require 100psi in the front tyre.
 

RecordAceFromNew

Swinging Member
Location
West London
very interesting and quite a difference front and rear, or at least for the heavier rider :blush: you have to be pretty heavy to warrant as much as 100psi in a front tyre, even at 23mm size. According to my reading of the chart you need 100lbs up front to justify this, which means you, and bike, would need to weigh in around the 250lbs mark. Assuming a bike weight of no more than 30lbs that would mean you need to be North of 15.5 stone to require 100psi in the front tyre.

The problem is then you have 150lbs at the back, requiring 170 psi, unless you use a wider tyre.

I think the most important point made in the article is the importance of suspension loss - a super high pressure tyre may be great on the track, but will actually slow you down when it gets a little rough.
 

MacB

Lover of things that come in 3's
The problem is then you have 150lbs at the back, requiring 170 psi, unless you use a wider tyre.

I think the most important point made in the article is the importance of suspension loss - a super high pressure tyre may be great on the track, but will actually slow you down when it gets a little rough.

agreed, but not really an issue here, I run 28mm, 42mm and 2.2" tyres and my next change will be 32mm in place of the 28s.
 

VamP

Banned
Location
Cambs
Good article.

Works out at 90 psi front, 130 psi rear for me. Food for thought as I have been running 110 psi in both wheels thus far.
 
The problem is then you have 150lbs at the back, requiring 170 psi, unless you use a wider tyre.

I think the most important point made in the article is the importance of suspension loss - a super high pressure tyre may be great on the track, but will actually slow you down when it gets a little rough.
Cheers thats an interesting article, from quick (fag packet) calcs, I'm running about the correct psi on the rear for a 23mm tyre (100-105psi) but I could drop the front quite a bit (70psi ish) but the comments on suspension loss seem spot on :-)
 

brockers

Senior Member
And I'm 75 psi front and 95 ish rear on 23mms (according to the chart) which is more or less what I've found gives a fast and plush ride, and makes me want to get out on my bike and ride it. I don't think I've had a puncture in two years either. I used to squeeze in over 100psi (because that's what they do in the Tour de France, right?) into both tyres which would result in my 9 1/2 stone carcass bouncing all over the poor quality blacktop.
 

swee'pea99

Squire
Have to say, that article certainly gives me pause for thought. I've been using that 120/100 for years, having been advised it as a good defence against You Know Who, but according to that chart, I'd be better off with 120/70, give or take, which comes as quite a surprise. Think I'll try it and see how it goes (tho' 70's going to seem awful soft - I haven't run a tyre at that kind of pressure since I can't remember when.)
 
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