Conti GP 4000s

[bc_hills]

Just picked up my first set of Continentals (Grand Prix 4000s) and am very happy so far. I do have a couple of questions:

1. is "3x110 tpi" a standard way to measure tpi count? Is this a 330 tpi tire?

2. Max inflation is 120 psi. I've always had 140 + max tpi clinchers and when I thought it mattered (i.e. keeping up in group rides)) I'd pump them right up. Will a 120 max psi mean a higher rolling resistance than a 140 max psi (assuming they're both pumped right up), or are the other more important factors I need to consider?

Thanks!

 

[Oldman]

Just picked up my first set of Continentals (Grand Prix 4000s) and am very happy so far. I do have a couple of questions:

1. is "3x110 tpi" a standard way to measure tpi count? Is this a 330 tpi tire?

2. Max inflation is 120 psi. I've always had 140 + max tpi clinchers and when I thought it mattered (i.e. keeping up in group rides)) I'd pump them right up. Will a 120 max psi mean a higher rolling resistance than a 140 max psi (assuming they're both pumped right up), or are the other more important factors I need to consider?

Thanks!

If you are heavy you can go to the 140psi but the ride and handling will suffer. These don't ride well in the wet so go to 100-for wet handling.

 

[BroDeal]

Are they better than the old GP3000s? After using the 3000s for a while, I swore off of Continental tires because they had p!ss weak side walls.

 

[Vegan Dave]

Yes, i've found Conti's have poor sidewalls, but i actually nearly wore through the tread on my last rear tire.

Doesn't sound like much, but given that i used it as a winter tire with fenders, that means it survived more debris and fender rubbing on the sidewalls....so imo, the sidewalls seem to be improved!

As for the PSI, i used to ride up in the 120 range, but have been riding a bit lower, like 105, and liking it. Depending on the roads, the higher pressure may actually work against you.

 

[Oldman]

Are they better than the old GP3000s? After using the 3000s for a while, I swore off of Continental tires because they had p!ss weak side walls.

Rode these and the Force version down to the cord. They are better at resisting side cuts, for sure.

 

[Speedneedle]

Most tires has lowest rolling resistance between 100 and 120 psi, depending on rider weight. A lot of people still pump their tires too hard with less comfort, less grip and higher rolling resistance as a result.

High tire pressures feel faster, but isn't unless you are riding on a track with perfect smooth surface.

 

[dajonker]

Rolling resistance is not dependent on the max pressure of a tyre, but rather on the rubber compound and suppleness of the tyre.

 

[markrosen]

If you are heavy you can go to the 140psi but the ride and handling will suffer. These don't ride well in the wet so go to 100-for wet handling.

You are absolutely correct, these tires are great in dry conditions, but slip & slide a bit in wet (even w/ lower pressure). If you can afford it, use the Vittoria Open Corsa Evo CX in these conditions.

 

[Condorman]

Worth noting that they are directional (the tyre is marked with direction of rotation).
They are fine in the wet.

 

[Notso Swift]

Just picked up my first set of Continentals (Grand Prix 4000s) and am very happy so far. I do have a couple of questions:

1. is "3x110 tpi" a standard way to measure tpi count? Is this a 330 tpi tire?

2. Max inflation is 120 psi. I've always had 140 + max tpi clinchers and when I thought it mattered (i.e. keeping up in group rides)) I'd pump them right up. Will a 120 max psi mean a higher rolling resistance than a 140 max psi (assuming they're both pumped right up), or are the other more important factors I need to consider?

Thanks!

I believe they 3x110 tpi is because they are a 5 ply tyre
Grip surface
1 ply of casing, 110 tpi
Breaker (puncture resistance)
2 more ply's of casing, each being 110 tpi


Just note that some tyres have been known to have a high TPI count yet the "strangely" feel quite stiff, without the suppleness that you should expect from a high TPI. I always suspect that these are cases when one or more of the plys are a different weave to the "headline". Conti's (I feel) are the most "honest"of companies with there marketing spiel... they tell you when a tyre is lightning fast but not suitable for everyday

With pressure: Have you checked the rating on your rim?

 

[euanli]

I spend half the year riding in the wet and I actually think these tyres perform better in the wet. I also rarely puncture, maybe once or twice on the current set. Ride 100/105 but I am I light rider.

 

[Roadscrape]

2. Max inflation is 120 psi. I've always had 140 + max tpi clinchers and when I thought it mattered (i.e. keeping up in group rides)) I'd pump them right up. Will a 120 max psi mean a higher rolling resistance than a 140 max psi (assuming they're both pumped right up), or are the other more important factors I need to consider?

A few have pointed out that higer pressure, 120-140 psi is not needed.

That information came from tire tests developed by Continental and Schwalbe. The tests showed that a 25 mm tire will be faster than a 23 mm or narrower tire. The reason is due to the shape of the contact patch with the pavement. The narrow tire contact patch is a longer oval, whereas the wider tire has a nearly round contact area.

The testing also showed that a 15% tire drop is faster than a tired inflated to max. press. Thus ideal tire pressure is a function of total weight the tire supports. Test showed that tires inflated to max. press. did not conform to road surface irregularities, but instead spent a lot of time micro-bouncing off such surfaces, thus actually slowing the speed of the tire and wasting rider energy.

The tests showed that a tired that can flex just enough to conform to the pavement not only rides better, but is more efficient and faster than a hard pressured tire.

One can counter that harder tires are faster ad infinitum - but as one poster correctly stated - only on glass smooth surfaces like a velodrome track.

Debate as you will, but I've found in my experience that the recommendations from the test did result in a better ride - can't say about faster really (my tires aren't ready for replacment but I will try 25 mm next), but certainly as fast - not slower (Conti 4000, 23 mm, 105 psi/rr; 95 psi/fr - total weight - rider, bike, water, gear < 20 lbs.). So with less pressure, I get a better riding tire that is just as fast, handles no differently, and has better wet road traction.

What's not to like?

 

[bc_hills]

Thanks for all the posts! I've never been on a more helpful forum.

The roads I'm on are in great shape for the most part, and I really notice when a tire is low on pressure. I can feel it drag and all I have to do is look down and see what I know is already there, a tire sagging out at the sides. I keep them pumped tight so that there's almost no deflection of the tire and I'm reasonably confident that I move faster/easier because of it. Until I hit a rough section of road, and then it's like I'm hitting bricks and it is slower for sure. Self deception is always pretty easy though.

About that tire pressure study vis-a-vis rolling resistance, it would be interesting to find a link to it. Seems like there are so many variables to control for that it would be a difficult to reach good conclusions. There was another study that "showed" that clinchers have less rolling resistance than tubulars, although many pointed out that a potential flaw in the study was that it measured tires all inflated to the same psi, rather than individual tires inflated to a psi suitable for the tire itself. So they did find that tubulars were "slower" than clinchers, but they were running tubulars rated for 200 psi at 120 or whatever it was.

The reason I was asking the question about the tire pressure was that on the same roads under the same conditions, the contis at 120 psi (max rated psi) rolled better than my rubino pros at 140 psi (max rated psi). I had been under the (clearly mistaken) impression that max psi affected rolling resistance.

Cheers!

 

[SergioMoretti]

Marketing Gimmick

Worth noting that they are directional (the tyre is marked with direction of rotation).
They are fine in the wet.

While it's true there's an arrow indicating direction of rotation, it's *not* true that it makes a difference. Apparently, those in marketing decided a "directional" tire gives people the perception of advanced technology...

I advocate running the lowest pressure that reliably prevents rim cuts. For me (165 lbs.) riding relatively good roads means 95 psi front, 105 psi rear.

- Sergio

 

[Condorman]

While it's true there's an arrow indicating direction of rotation, it's *not* true that it makes a difference. Apparently, those in marketing decided a "directional" tire gives people the perception of advanced technology...

I advocate running the lowest pressure that reliably prevents rim cuts. For me (165 lbs.) riding relatively good roads means 95 psi front, 105 psi rear.

- Sergio

Sergio! I bow to your superior knowledge. Worth waiting a while for a first post like that.
I have turned my tyres round and reduced the pressure as you advocate.