southpawboston

Thought I'd post this in C&V since both these brands appeal to us C&Vers.

My Mercian is currently shod with Challenge Parigi-Roubaix tires, which are labeled 700x27 but measure a true 29.0-29.5mm. It's the widest tire that can fit the bike, and I'm happy with them. They're comfy and roll fast, but I'm concerned about their tendency to flat. I want to able to ride this bike more frequently on dirt roads, and I haven't flatted yet, but just about every review of this tire indicates it's only a matter of time before they do.

It seems the GB Serf in 29mm is a perfect substitute for the Challenge P-G in terms of size, ride quality and speed, and the reviews back this up. However, missing in a lot of the reviews is their flat resistance. I'm *guessing* they are more flat resistant. Can anyone back this up with personal experience? If they are truly more robust than the Challenges, I'd be willing to shell out the $120 for a pair, but if they're flat prone as well, they're no point in upgrading.

Just for kicks, I'll make it a poll. Keep the Challenge P-Gs or shell out for the GB Serfs.

JAG410 

I've heard the key to both tires longevity is higher pressures. Where you might want to run 80psi, run 100. Something like that. I'm running Ruffy Tuffy tires so I can't comment on the 2 you have listed, but I'd really like to try the Cerf's myself.

Edit: I'm really impressed with the Ruffy Tuffys. fast, comfortable, trouble free so far (~350 miles).

CV-6 

You are happy with the Challenge and you have not flatted. Carry a patch kit. Enjoy the ride. Buy the GBs when the others wear out.

dgodave

Do you know that the GBs dont run a little wide too.... in which case they might not fit your bike.
.

MrEss

I have only used the p-r tires so I can't comment directly on the cerfs, but I must say that it sounds like your problem isn't flatting, but worrying about flatting. In 1500 miles or so of mixed asphalt, gravel, and dirt riding, I have flatted every few hundred miles. It has not been beyond my level of tolerance, but maybe beyond that of others.

+1 keep the great tires you have, carry conservative supplies ( maybe patch kit, spare tube, co2, and a Silca pump? ), and don't worry about replacement until the day you scream "if these blasted things flat one more time...!" Then maybe think about the cerfs, which are still very thin but probably a little tougher due to being molded into shape instead of glued by hand.

southpawboston

I've always been confused by this logic, yet I've heard it before. My own intuition tells me that lower pressure reduces flats (other than pinch flats, which have nothing to do with tread penetration), because you have more surface area of the tire making contact with the ground, and less pressure per square inch that a sharp object can exert on the tread.

I wondered about that, but from what I've read, most Cerfs start out around 27mm and stretch to 29, so it should be good. Plus if they stretch to 30, they'll still fit.

Yeah, sounds like a good plan. I keep a patch kit/tube/pump with me at all times, so I guess it really comes down to just not liking the anticipation of a flat.

jptwins

+1

if you replaced them, they'd just be hanging on your wall unused, which is not where they want to be.

illwafer

CV-6 

Or he could sell them to another member at a substantially discounted price.

jonsan

I have been thinking about trying some myself and would be interested to see if anyone out there does have some first hand experience with both tires.
According to Compass Cycles, the newer P-Rs have a vulcanized tread as opposed to hand glued and I also wonder how this affects durability as well as the ride quality:
https://www.compasscycle.com/tires_chal_700_29.html

gomango

I would be happy to try the Cerfs, but I don't have the room in the stays on my Hollands.

The Challenge P-Rs have been a treat for me. A very nice performance tire for the dollars.

-holiday76

I have the cerfs. Tried to fit them on my Razesa. No dice. The rear just cleared with but the front rubbed the fork crown. Anyway, I can't really speak to how they ride yet. But I will soon because I think they're going on my Carlton Flyer. The only thing I can say is that they went on the rim easily enough.

Charles Wahl

As an ardent dialectical materialist, I am compelled to inform you that unceasing revolution is the only answer, and my sympathy lies with the Serfs, who shouldn't be ridden.

southpawboston

Oh you're just looking to start a feud.

spurious

What makes these Grand Bois tyres so good? They are damned expensive at $120 a pair. Whats their advantages over a Panaracer Pasela TG?

MrEss

Totally different priorities in in design and construction. The pasela TG tires are meant to be impervious to debris while still riding OK. The GB tires are much thinner and all about rolling resistance and ride quality even if that means they are less tough. Partially the expense is fancier material, partially it's just supply and demand.

MetinUz

Last month I put on P-R tires and went on a 300K. I flatted mid ride, got separated from the main pack and struggled the rest of the ride. I considered ditching them, but went on to use them on a 400K, and so far so good. They feel cushy and fast, but not a lot of rubber to protect from glass shards, etc. I don't think Serf's are any better, get Pasela's if your main concern is flat resistance.

753proguy

I have found the GB 26s and 28s to run about a mm narrower than marked size, so 25 and 27. This is on vintage (19-20 mm wide) rims. Rim width matters.

Neither the GB nor the Challenge P-R is a good gravel tire, imo. Great road tires, though....

Edit: ...and I don't buy the 'growth over time' argument. Just checked a set of well-used 26 GBs. 25.12 mm wide after about 2200 miles and 1.5 years.

tarwheel 

If you aren't wedded to skin walls, you might also want to consider Continental GP 4 Seasons, Clement Stradas or Vittoria Rubinos, all of which are available in 28 mm folders. I've run GP 4 Seasons on my commuter with very few flats and excellent durability; they are also light weight and roll fast. I have heard similar reports about the Clement Stadas. I've got 25 mm Rubinos on one of my bikes now and they roll very nice and are reportedly very durable. For a little more weight, Vittoria Randonneur Hypers are supposed to roll very nice with excellent durability. Plus, there are always Conti Gatorskins.

MetinUz

I run GP 4 Season's on my commute bike, they are great tires. But they are much narrower than the Challenge PR's. I would say 28mm GP4S is more like 25mm, and PR is more like 29mm.

gomango

I don't do loose gravel with my P-Rs, but tightly packed class 5 around here seems to be fine.

One of my longer loops here goes out to the western Metro and over 1/2 the ride is on class 5.

No issues in three seasons.

tashi

I have GB's in 28c and love their feel.

One of em had something weird going on, I kept getting flats (4 of em!) in the same spot on my front tire so I put a patch on it in that location and they stopped. I couldn't feel anything in that spot of the tire, but something was definitely up.

I have about 1500k on em now, most of it winter commuting, 25% of that on gravel paths and have had two more flats. In both cases it was due to a short section of brake or shifter cable poking through, picked up by the tire from my patio floor.

I can't say they're particularly bad or good as far as flats go, but they feel, look and grip great. One could say that the front tire with the repeated flats was defective I guess, but the fix was easy enough.

Be glad you're not buying them in Canada, I think they were closer to $180/pair up here! That being said, my Challange CX tires were $95 each if you paid full retail...

Grand Bois

What?

CV-6 

Clearance, Clarence.

jan nikolajsen 

If I choose one of those sensuously smooth rolling tires it has to pry off and get back on the rim with ease because I'm going to flat a lot more.

Excuse me for not staying on topic (Challenge vs GB), but you should also consider the Conti Grand Prix 4-Season in 28mm. Light, fast, reasonably puncture resistant, easy to mount/unmount, normal price. And if you look close you can see the tan wall. A bit dark but it's there