By Jim Langley

Before I get to the punch line hinted to in the title, a little personal tire history is in order. You’ll see how it’s related in a bit.

Since I first tried them, back in the late 1990s, I’ve been exclusively riding on Continental Grand Prix 4000 clincher road tires on my everyday bike – my Litespeed Vortex. The GP 4000 tires I use are marked 700 x 23c, yet actually measure 24.35mm wide, so they are wider than the label states – almost 25mm, which is the width I have preferred going back to my first road riding.

As you probably know already, going to wider tires that also allow running lower pressures is an easy way to enjoy a more comfortable ride. Over the years, we’ve shared research by Jan Heine at Bicycle Quarterly magazine showing how they are just as efficient to ride, too. And Jan contributed an article to RBR back in March of this year titled The Tire Pressure Revolution that explains it very well.

Tip: In selecting new road tires that are wider than what you use now, the only way to be certain that your frame and fork have enough clearance for the tires to fit and not rub anywhere is to know the true dimensions (width and height) of the fully inflated tire before purchasing. Keep in mind, too, that frame clearance varies, so just because a wider tire fits in either the front or rear, it might not fit in the other. Check and measure carefully before buying.

Great flat protection

The reason I went to the GP 4000 tires initially was because they came with new flat-fighting technology in the form of a tough Vectran layer. It worked great on broken pavement and even on roads strewn with glass and other debris. In fact, I stopped worrying when I didn’t see glass and rode through it by mistake because I never flatted.

I also found that the GP 4000s rolled and cornered as well as any tires I had ridden before and lasted longer than most, too. And, I felt and feel that they provide a nice supple ride so I’m able to ride as long as I like, without any issues with road vibration causing discomfort or fatigue (FYI: I weigh 165 pounds/74.8kg and inflate the tires to 100/95 psi, rear/front).

Note that Continental has offered different versions of the GP 4000 tires over the years, like their current Black Chili models. They all offer stellar flat resistance and road performance, in my experience.

My durability experiment

These tires aren’t inexpensive, ranging from about $55 to $75 per tire, depending on the source and exact model. So, I have a hard time throwing the tires out when I remove one that’s showing a lot of wear. As a result, I ended up with a pile of about 40 tires I’d removed but had been unable to toss in the trash.

What I do is take rear tires off when they’re squared off significantly and I start flatting, which is the sign that the tread is worn past its limit. Front tires stay round and wear at a much slower rate. The GP 4000 tires have wear indicators you can refer to that help you know how worn the tread is.

Last year, looking at that pile of old tires and thinking of how much money they represented, I decided to experiment with those tires to see if they were actually completely shot. That way, I could finally throw some of them away without feeling guilty. I started putting them back on my rear wheel instead of buying new tires.

Over a year later, I’ve saved a bundle of cash and have now gone through almost all of my old tires. What I found was that every one of those supposedly worn-out tires lasted several hundred more miles before the tread actually wore down to where I could see the tire casing peeking through in spots. This proved to me that the GPs are even more durable than I thought they were originally, which makes me like them even more.

Tire study suggests that there may be a new top tire - at least for speed

Now, to finally get to the punch line I promised: All of my positive Continental Grand Prix 4000 tire experiences and observations came back to me the other day when I read Lennard Zinn’s latest tire story in VeloNews.

Lucky Lennard went to Nastola, Finland, to visit what he calls (and he would know) the top rolling resistance lab in the world, Wheel Energy Oy, to learn which new bicycle tires came out on top of their recent tests. The measurement they use is watts. The fewer the watts required, the better the rolling resistance and tire, and the faster the tires.

The surprise to me was that the winning tires were Specialized’s new line of Turbo tires. (I actually heard from a teammate who recently switched to these tires that he loves them, so it wasn’t a complete surprise). First place in the tests went to Specialized’s S-Works Turbo Road Tubeless 26mm-wide tire at 31.6 watts. Next was their Turbo Cotton tubular 24mm-wide tire with a result of 31.7 watts, followed by the S-Works Turbo clincher, 26mm wide, at 32.8 watts.

But, it turns out that I shouldn’t have been too surprised, because Lennard explains that Specialized hired away two of Continental’s top tire designers to help them create their new tire line. And, the great news for me – and all of you riding the same Continental Grand Prix 4000S II clinchers that I ride, is that they grabbed the 4th spot with a rating of 34.0 watts.

The tests did not evaluate flat resistance or durability, in fact, so it might be that Contis still have an overall edge.

Tip: As others have shown in previous tests, Wheel Energy Oy’s study found that latex tubes help reduce rolling resistance. They’re more expensive than standard butyl tubes and they can require topping off your tires more frequently, but if you’re looking for free speed you may not mind.

Jim Langley is RBR's Technical Editor. He has been a pro mechanic and cycling writer for more than 40 years. He's the author of Your Home Bicycle Workshop in the RBR eBookstore. Check out his "cycling aficionado" website at, his Q&A blog and updates at Twitter. Jim's streak of consecutive cycling days has reached more than 8,000. Click to read Jim's full bio.

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