chas58

GP5000 32mm

Finally - high end 32mm tires! Not too long ago I got excited just to see 28mm sizes. And Conti has finally gone tubeless (although they are a PITA for my wheels).

Construction:

Standard tubed tire feels like all the other conti road tires I’ve had. No surprises

Tubeless feels a lot different. Thicker rubber especially noticeable on sidewalls. Does not feel so floppy and thin in the hand. (means extra weight and maybe less supple ride?). It is 60 tpi, not 110 tpi of the standard tire – so the cords are thicker (and presumably tougher). In theory this makes for a tougher tire. Between the thicker bead and thicker sidewall and oddly slippery feeling – it feels more like a car tire to me, oddly.

Mounting:

The standard tires were a very tight fit, but snapped onto my tubeless rims and fit fine.

The Tubeless tire was a nightmare. I’ve been mounting tires for ~45 years, but never gave up on mounting a tire. I thought Schwalbe was hard to mount, but these are much harder. Two things make it difficult:

• Like Schwalbe, the bead is very tight and is hard to stretch around the rim.
• The bead on the tire is super thick. I struggled to get the first bead on (by hand) but gave up on the second bead. Best as I can figure – the bead is so thick that it fills the bead channel making it hard to get the second bead in the channel – and without that the tire isn’t going on the rim. For the first time ever, I ate humble pie and took it to my LBS. Two of them spend 40 minutes getting the rim on the tire, but they finally were successful. I’m impressed they stuck with it. It definitely was a 2 man job. As one person pulls the bead on, the second person has to keep the other half from walking around. It was really a struggle. If there is a catastrophic flat on the side of the road, it time to call uber. This isn’t a road side repair.

Possibly because I’m using “hookless” rims, my rim bed it tighter. In comparison, my Schwalbe’s were hard, but not impossible. My Maxis tires were fairly easy. Any “tubed” tire is tight enough to use “tubless” but still go on by hand (rather like my Maxis ramblers). These tires are easier to mount on other rims, I'm told. I'm thinking a rim that relies more on a hooked rim (rather than the rim bed that the hookless rims use) would be easier.

This high pressure capable design is overkill for a tire destined for gravel. The tire is rated for over 100psi, but I’m not going to use it over 60psi.

Continental’s Sizing on 22mm ID rims
4Season 28mm: 27mm (on 19ID)
GP4000 28mm: 31mm (30mm on 19ID)
GP5000 28mm: 28mm (on 19ID)
GP5000 32mm: 33mm
4Season 32mm: 35mm
(sometimes I wonder why they bother labeling their tires, they don’t seem to put much effort into it, lol)

Road riding:

I’m surprised at their speed. Really surprised. They are nice solo riding, but amazing in a pace line. With a paceline reducing a lot of the aero drag, rolling friction plays a significant part.

One thing I didn’t realize until I road these is that they only have 8.3 watts of resistance at 18mph. That is about 23 watts for the pair at 25mph paceline.

Compared to the Conti 4seasons I had been using have 50 watts resistance. The difference was more noticeable than I had thought. The biggest metric change was that my heart rate had lowered by about 5bpm. That is crazy. It felt like I was riding on ball bearings (or more accurately, riding on my rollers and just spinning along).

These seemed like “cheater” tires. 32mm and tubeless makes this some of the most efficient tires ever made. I felt like I had a dirty little secret. Even looking around me at the other riders on GP5000s, I had my little secret. All these road race bikes were one 23mm tires. Those have to be ~100 PSI to get the same rolling resistance as I was at 70psi. With as rough as our roads are – I was just able to glide over this rough asphalt much more effectively than the same tire at 23mm (not to mention that these rough roads have been giving the 23mm tires a lot of flats this year).


Gravel & For off road – we’ll see. It’s a 3 ply tire, but the diagrams show 2 ply sidewalls, plus a breaker ply under the tread. The tubed tire at 110TPI looks to have almost a see through sidewalls – in that I can see the chords on the inside and on the outside of the tire. The tubed tires are 60TPI – and have an airtight sidewall. Thicker cords and more rubber. Should make it more scuff resistant and a better gravel tire than the tubed tire. Time will tell...

Rides4Beer

I have 28mm GP5Ks with tubes on the road wheels I use on my gravel bike, love them, they measure at 30mm, are very comfortable and handle great. I'm somewhat interested in trying them in TL, but the more I read about how hard they are to mount, the less inclined I am to try them. I'd never run a tire that I couldn't fix on the side of the road.

shoota 

Great review! I've heard the same awesome things about these.

My question for you: what do you plan on doing if you get a non-catastrophic flat?

chas58

Uber.

I have plugs and gorilla tape. It would have to be a good sidewall gash - and if its that rough I'm on larger tires. But when a stick ripped off my derailer last year, it was uber time.

TimothyH

Is this actually the case, that tires with fewer TPI have thicker/tougher cords?

Or are there just less of them?


-Tim-

redlude97

Generally yes. You still have to fill the same surface area and the casing wouldn't/shouldn't have gaps in them. The only time that isn't the case is when conti tries to cheat by claiming 3x110 tpi=330tpi layered

chas58

The Tubeless tire has thicker cords (you can see them) and more rubber on the sidewall that should make it harder to tear a gash in them. It doesn't seem to affect ride quality or rolling resistance. The tubed tire sidewall is pretty flimsy - as is typical for a race oriented tire.

My impression is that they did a lot of work to make the tubed tire work as well as the tubed tire and match it in all characteristics (even weight if you add in the weight of an inner-tube).

gravelED

Nice review chas58, I was wondering if these have grown any or are they still 33mm on 22mm ID rims?

chas58

they seem true to size, depending on rim

with 22ID, my GP4000 28mm measure 31mm, but that rim is too big for that size tire (sidewall issues).
on those rims the GP5000 32mm measure 33mm, and the 32mm 4season measure ~35mm.
I have some GP5000s 28 on some skinny rims, and they measure 27mm.

So, the old 28mm is in between the new 28 and 32mm; the new ones are fairly true to size (bicycle rolling resistance tested all 4 sizes of the 4000 and 5000 if you want more hard data).