Super D

Hi guys, I just started running the Conti GP4000 S II tires about 7 weeks ago. I've been getting some pretty big cuts, more so than in other tires in recent years.

These are grippy, fast tires, but I'm sort of getting concerned that they're a bit too delicate to train on. I originally bought them due to the reports that they had a great combination of low rolling resistance, and the newest "II" version had better puncture resistance.

Note that I've not flatted (yet), but the tires have developed cuts that have begun to "flower", meaning, they've turned from big slices, to spreading ovular holes with frayed edges. I'm taking the tires off tomorrow, for fear that under cornering, braking or high surface temps, the areas which are cut will deform or burst. Not worth the risk.

What's your experience been with these tires, do they seem prone to cutting easily?

I don't want to run a heavier tire with poor rolling resistance comparatively, my preference is to use a tire which is fast but also durable--if possible. I'm beginning to wonder if that's unrealistic. Coming from an auto racing background, where there are in fact racing tires which are also very durable, I was hoping to find something similar for the road bike.

SundayNiagara

Here we go again.

BillyD

kleng

What tire pressures are you using ?

aubiecat

Uh Oh.

Super D

Ah, shoot, I didn't find the threads that evidently have been beaten to death millions of times before this. Searched, didn't find. I'm specifically looking for info on the easy tire cutting I'm seeing, not just general "what do you think of the GP 4000S II, and are they better than Gatorskins or the GP 4S" type of thing. Just looking for users of this exact tire, to see if others are getting the big cuts like I am.

Anyone care to share a link to one that discusses this problem?

Thanks, and sorry for the repeat.

Super D

I run 105-110 f/r, depending on temps of the day. Lower pressure for hot days to compensate for pressure increases running on hot roads.

Up North

4 weeks of 125-150 kms a week and no issues with mine, running 25's 95 front 100 rear, 210lb rider.

Super D

I'm running 25s as well, weigh 187 lbs, avg 120 mi/week.

Wondering if I'm just running too high tire pressure? I've read lots of threads where some people run the same pressures you are, and others run 110 or 120. Can't seem to find any consistency or scientifically derived pressure based on instrumented testing.

Carbonfiberboy 

I know from comparing my cutting and flatting experiences with various tires that different areas of the country have very different effects on bike tire wear, and also rim wear. There's no way to compare your results with another person's unless you always ride together at at least do the same long rides together. Because I do a group ride every weekend with people I know, I've been exposed to discussions of wear factors for a great deal of equipment which I haven't had to personally test, and which discussions basically agree with my results with similar equipment. So ask someone in your area who runs those tires, not on a forum like this.

Super D

With respect to your rationale, which is definitely sound, I'd offer this: if a rider in one area has tried several tires over time, and then tries the Conti GP4000S II and has experience with the propensity for that tire to suffer cuts versus the others they've tried (or not), that comparative data is valuable, no matter where they are. It's experience with the tire relative to other tires used in their area, on their typical routes and terrain, that I'm looking for in order to recognize trending or lack of it.

The Conti GP 4000S is a very popular tire from what I've noticed online, and in my area. So is the Gatorskin. I transitioned away from the Gatorskin to find better cornering grip and lower rolling resistance. If this comes at the expense of durability, and it's fairly severe, I need to search for another solution that isn't so delicate. I'm reserving judgement for now until I can gather some other opinions. I will definitely survey fellow riders in my area as well in order to gather diverse feedback, thanks for the suggestion.

Here in San Diego, I ride on varying surface types and varying temperatures depending upon the season. Yes, I know, here come the "it's always sunny and 70 in San Diego" snickers, hehe, that's mostly true, but...it drops into the high 30s in my area in the Winter and can exceed 95+ degrees during hot spells. Some roads are smooth, some rough, some with debris, some clean. I can ride near the ocean, desert and mountains, all within 100 miles. Currently, I'm riding near the ocean and mountains. I would consider the road conditions to be varied, some newly paved, some old and cracked, some sandy, glass and debris encountered infrequently.

My challenge, shared by many, is to find a racing-worthy/high performance tire with excellent grip, low rolling resistance, and durability. Tough combo to satisfy, but I'm not giving up on attempts to get as close to that criteria as possible.

Chandne

Not sure exactly how they "improved" upon the originals but I run the originals (GP 4000S) here in Colorado. PSI- 100/105 or 100/110. I have run 95/100 as well. After 600-700 miles, I have not noticed any unusual cuts- just the usual nicks. I ran through sand, mag chloride, and some gravel a few times. I also ran through fine glass twice. Overall though, our roads are pretty clean and they sometimes get cleaned by sweepers too. Hopefully they have not screwed up a good tire.

Dunbar

The 4000S II's are pretty new but I doubt they're any different than the 4000S in terms of resisting cuts. I've done 11-12k miles on GP4000S tires on the west side of Los Angeles and have not seen anything but tiny cuts on the tread which don't impact tire life. I developed the habit of scanning the ground when I lived inland so I tend to avoid running over shiny objects.

Super D

Interesting. Wonder if the tread compound on the II version is less rugged than the previous. I'd read that the new one was just improved in terms of the vectran breaker inside for better puncture resistance.

I've read that the sidewalls are easily cut, but I haven't experienced that yet (although I have with the new Mavic Yksionby comparison, very delicate sidewalls evidently).

Super D

That's great mileage, wow. I was thinking 3k-4k tops would be realistic, you really got a ton of distance out of those.

Carbonfiberboy 

Oh Mr. D, I was just trying to weasel out of actually commenting while pointing out the possible variability of experience.

But yes, they cut easily and suck up stones and glass. Michelin PRO4 Endurance do not. They're what you're looking for. Everything else is somewhere in between in terms of current offerings. I go through a lot of tires.

Super D

I was looking at those before purchasing these! (Thanks for not weaseling out, btw.)

So now you've done it, you have to share some details. Ride quality, grip, speed, etc. How do you compare the MP4 Endurance vs the Conti GP4000s (other than not sucking up glass and rocks)?

Thank you, really appreciate it.

Edit: Oops, I forgot. I was looking at the MP4 Service Course, not the Endurance.

Dunbar

I'm on my second set. I get maybe ~6-7k out of the rear tires and ~9k out of the fronts. The fronts could probably go forever if I ran them down to the cords but I'm not comfortable leaving them on for that long.

Carbonfiberboy 

I haven't run the SC so can't comment. As far as grip in wet and dry, apparent rolling resistance, ride quality - all about the same or better than the Conti. I have run 25mm versions of many tires. A big difference with the 25mm Endurance is that after they stretch out for a week or so, they measure ~27.5mm. Again, I don't know about the SC. I'm running these tires at 110 lbs. on our tandem, 295 lb. team, so that's pretty rough service. The 25 Endurance weighs 245g, while the 23mm Endurance weighs 225g. The Conti 25mm weighs 225g.

Besides the SC there's now a Grip SC, both only available in 23mm.

It would be interesting to hear from folks who are running the SC or Grip SC. I know there are folks on this forum who train and race on the PRO4 Endurance.

gamby

I'm baffled by those mileage numbers. At 185lbs, I can cord a rear 700x23 Bontrager R3 in 1200 miles. I've got ~1200 miles on a rear 700x23 Conti GP 4-season and if I'm lucky, I'll get another 500 out of it before it's paper thin. BTW--those are the best tires I've used to date in terms of cut resistance.

My beater tires are 700x25 Conti Supersports that weigh a ton (390g per tire), but they're nukeproof, so it's worth it to me. Will be putting 170+ miles on those this weekend (MS150 w/ day 1 century).

f4rrest

I've run conti 4000S (23mm) for a few years (20k miles) and haven't noticed a propensity to cut. The sidewalls are susceptible to UV damage.

Two weeks ago, I switched to Pro4 SC (25mm) and don't really notice a difference between them other than they're HUGE. I'm currently doing 200mi/week commuting, fast group rides, and mountains. I'm a fast descender and feel confident on either brand of tire in hard corners.

Dunbar

I was surprised too since other people don't appear to get such great mileage. But the GP4000S has wear dots on them. When they are no longer visible you replace the tire. My current rear tire has 5000-5500 miles on it and both wear dots are still visible. I'm currently 160-165lbs but on my first set I weighed more like 175lbs. Not sure if it matters but I air up my tires before every ride.

(Not my tire)

f4rrest

I get about 3k on my rear 4000s. I'm 175 +10lb messenger bag. Running at 110 psi.

Dunbar

My last rear GP4000S tire punctured three times in one week at around 6k miles on it. One wear dot was close to being flush so I replaced the tire. I posted a question on RBR (with photos of the tread) and most people told me to keep running it until the cords were showing!

DXchulo

Those wear dots seem unnecessary, don't they? Who doesn't know when to replace a tire?