granp prix 4000 tires

[shotojs78]

usually I ride on vittoria open corsa, I can put 8 to 10 bar (-145lbs) I use 125lbs. I'm 5'10'' 200lbs, so according to you, the GP4000 can take just 110lbs..is it enough for me, I think I'M too heavy for 110??

[Sandy]

"....according to you, the GP4000 can take just 110 pounds,.." Who is the you in that statement? Don't think your info is correct. I assume that you are using 700x23 tires. If you are, the recommended tire pressure is 110 psi and the max psi is 120. That information is found on Continental's home site and also on the box in which the tires come. I rode Continental 700x23 GP 4000 tires at 105 f and 115 rear and that was at weights well above yours.- up to 225 and more. I now use Continental GP 4000 700x25 tires and use 95-96 psi front and 105-106 psi rear. The recommended per Continental is 95 psi for the 700x 25tire, but even those have a max of 120 psi per Continental.

110 would probably be fine for you and if you went higher there would be no problem as the max is 120. Even that number is conservative I would think, as a tire manufacturer will always protect itself from liability issues and be on the conservative side. Go to 110 or 120 if you want. The higher you go the less chance of pinch flats (probably have little anyway at 110), the less rolling resistance, but a greater tendency for flats, less comfort, and poorer tire wear.

Go with them anywhere between the 110 and the 120 I would confidently say.

Try a pair. If you don't like them, I will buy them from you for what you paid, and give them to a friend who uses that tire in that size.


Sandy

[TMB]

usually I ride on vittoria open corsa, I can put 8 to 10 bar (-145lbs) I use 125lbs. I'm 5'10'' 200lbs, so according to you, the GP4000 can take just 110lbs..is it enough for me, I think I'M too heavy for 110??

Well,
I'm about 200 pds and run with 90 to 95 in front and 100 to 110 in the rear.

Perfect.

[Sandy]

What size, please?


Sandy

[TMB]

What size, please?


Sandy

I'm pretty non-discriminating.

Used to run the 700x 23's at those rates and was quite happy.

I have pretty much completed the switch to 25's ( 1 pair of 23's left), and am running those at those pressures as well. Even better.

[Sandy]

As I said, I use around 95 f and 105 r for the 700x25- very clsoe to what you use.. They are definitely more comfortable, probably just as fast or faster, and handle better too. My weight has ranged from 190- 225 and more with those tires.


Sandy

[TMB]

As I said, I use around 95 f and 105 r for the 700x25- very clsoe to what you use.. They are definitely more comfortable, probably just as fast or faster, and handle better too. My weight has ranged from 190- 225 and more with those tires.


Sandy

MUch more comfortable, certainly no slower.

I like them.

[palincss]

Here's one chart (for 23mm tire) relating pressure to rider weight:

Rider Weight Road Tire Pressure (PSI)
110 95-105
140 105-115
170 110-120
200 120-130
230 125-135

-- http://hypertextbook.com/facts/2003/SharaKhan.shtml

The wider the tire, the lower the pressure required. One obvious defect with this chart is that no attempt is made to distinguish between front and rear tire, and based on how evenly the rider's weight is balanced over the two wheels, there can be quite a lot of weight difference and, consequently, tire drop under load & pressure required to keep that tire drop to the optimal 15% recommended by tire manufacturers. But it's a ball park.

IMO, once you hit that 200 lb (or, as I prefer to call it, 0.1 tons) mark I think you're much better off with a true 25mm tire. The pressure can be a lot lower and the ride can be much more comfortable, especially on poor road surfaces.

[FMS_rider]

As I said, I use around 95 f and 105 r for the 700x25- very clsoe to what you use.. They are definitely more comfortable, probably just as fast or faster, and handle better too. My weight has ranged from 190- 225 and more with those tires. Sandy At my weight of ~150 lbs I use 78f and 82r when I know I am going to encounter rough pavement with both GP4000 and Michelin Pro2 700x25 tires and have never had a pinch flat. There is undoubtedly a small increase in rolling resistance with those low pressures, but I cannot feel a decrease when I use an additional 10psi on smoother pavement

Lew

[Sandy]

At my weight of ~150 lbs I use 78f and 82r when I know I am going to encounter rough pavement with both GP4000 and Michelin Pro2 700x25 tires and have never had a pinch flat. There is undoubtedly a small increase in rolling resistance with those low pressures, but I cannot feel a decrease when I use an additional 10psi on smoother pavement

Lew

I think a lot of cyclists probably put too much psi in their tires. It might lower rolling resistance some on really smooth roads, but in the real world of cycling, roads are normally imperfect. The rolling resistance may be lower at a higher psi, but so will the adhesion to the road surface as the tires will tend to bounce more because of the higher psi. That will hurt comfort and can atually slow you down, at least that is how I perceive it.


:banana: Airhead Sandy :banana: