Tyres and Pressure
 

Hi all,

Not sure whether this has been discussed before. Would like to know whats everyone preferred pressure on their tyres.

I will start mine.

100front 110rear/ GP4000s 700x23 clincher/ Weight : 75kg

Ditto.
Only I have GP4000 x 25s on now. (Winter tires) 70.9kg

100fr
110rr
GP4000 23s
me+bike: ~80kg

I don't think any has ever posted about this before, never really thought about it actually. I've always just done the same as my car (because it's really fast :D ) so 36 in the front and 28 in the back.

90fr
95rr
Specialized Nimbus 35s
Me: 68kg
Bike (Sirrus, Winter Bike): ?? maybe 12+ kgs?

100 F/110 R
Pro Race 3 700x23 clincher
Weight: 72kg

85/85
Schwalbe Marathon Plus 35C
Weight: 110kg

Vredestein tricomps
125 rear
120 fr
175 pounds
I have on at times run 130 in the front.

Car - 35 Fr
42 Rr

Bike (normal ride)
105 Fr
115 Rr

(race)
120 Fr
135 Rr

gp4000s
95/100 (for normal every day conditions - lower in rain or a technical race course, higher for a non-technical race)
54kg

Thats about right................. for my cross bike. Cept maybe 30 f. and 35 r.

Switching from a Mountain Bike to Road bike I haven't thought much about it. I have 700x23 tires and was thinking 120 pounds. I weigh 100kg or 220 pounds. But I see some here on the same tire are running 100 pounds. Do I want the higher pressure or is this something you adjust to your own liking?

Hutchinson Road Tubeless 700x23:
100-105 front, 105 rear (probably should go 5 psi lower)

Gatorskins clinchers 700x25:
110 front, 115 rear

Weight is 85 kg

+1 on 5psi lower, I would even try 15psi lower and then add till you reach the sweet spot.
The Fusions like to run at 85 or so for me. 70.1kg

I'm going on Hutchinson's recommendations for my weight. Actually, it's just a bit lower. But I do need to try it lower. Which I will ... whenever I get out on the road again. I've ridden once so far this month--getting very stir crazy, and even going to order a trainer. Which I never thought I would. But it beats nothing ... I hope. :)

More pressure reduces rolling resistance up to a point; above some sweet spot you start losing energy when the tires get too stiff to provide suspension; road bumps that the tires don't absorb are passed on to the bike and you and the energy lost in vibration is energy which would otherwise be hurtling you forwards. The optimum pressure depends on the width of the tire and the total weight that it is holding up (i.e. both you and the bike, divided unequally over the two wheels).

According to this article the best balance of rolling resistance and suspension is with 15% drop: http://www.bikequarterly.com/images/TireDrop.pdf. It includes a graph showing the optimum pressure for a variety of widths and weights.

My racing bike has 700x23 tires and weighs ~190 pounds with me on it; I run 85# front and 110# rear.

My wet weather/rough road/grocery store bike has 700x37 tires right now and weighs ~200 with me, racks, paniers, etc.; I run 40# front and 55# rear. It is incredibly comfortable and actually rides faster than when I had 28mm tires running at 65/90!

Go too low and you risk pinch flats.

I just stop pumping when it's hard.

+1 for the BikeQuarterly guide. I haven't set up my front and rear wheels on a scale to determine what load they're carrying, so I just went by the 60/40 (rear/front) ratio.

23c
100psi rear
80psi front

me+bike = 157lbs


^^lol

Wow mine turns out scary. I am 241 pounds bike and me or 110kg. Using the 45/55 rule I end up at 120 psi front and 140psi back. Will my tubes hold 140psi??

Nope, not under 140psi. You should get bigger tires.

About 105 in front with a Michelin Pro2 Race
About 110 in back with a Schwalbe Durano

I weigh about 16 stone.

Wow mine turns out scary. I am 241 pounds bike and me or 110kg. Using the 45/55 rule I end up at 120 psi front and 140psi back. Will my tubes hold 140psi?? Quote;

The question is will you wheels take that kind of pressure?

110 front, 120 rear - for speed
100 front, 110 rear - endurance/comfort
GP4000s, Zipp 404 Alum Clincher
me+bike: ~100kg

Someone mentioned earlier the misconception that higher pressure = higher speeds. The basic idea is that you get a larger tire/road contact surface area as opposed to jumping and/or skipping on the road surface.

There was also a link posted to an article about 25mm tires being a bit faster than 23mm. Maybe you're already using the 25's, but thought I'd mention it. Might get the best of both worlds with 25mm: more comfortable and slightly faster (for us mere mortals at least).

I do it like I'm autocrossing my car. I'll start close to where you start and chalk my tires to see if I'm rolling them, and then adjust from there.