Tire comparison, Terreno Zero v Roubaix Pro
 

I am an old roadie, moving into sometimes road, sometimes gravel/dirt. Probably 80/20. I ride a Giant Defy, mostly flat lands in south Louisiana, occasionally hills. Anyone have experience or recommendations for the two tires I've found that look appropriate: The Specialized Roubaix Pro 2Bliss vs. the Vittorio Terreno Zero. Comfort, rolling resistance on pavement?

From what I've found online, the Vittorio seems like "gravel lite"....more geared toward hard-pack gravel with occasional road, whereas the Specialized looks more like a road tire that can handle occasional dirt, Size will be 700x32.

(Perhaps another option is just go with the new tubeless Continental GP5000 700x32 and deflate whenever I get to dirt?)

Thanks in advance,
David

I have the Continental GP5000 700x32's and love them on the road, but I would be a little nervous to take them off road for puncture protection. BUT, I don't know much and will be following this thread for more info.

You've pretty much nailed your assessment of the two tires. Our locel LBS owner rode a mixed surface race in northern Denmark on the TL5000s set up tubeless and loved them. I can only imagine those conditions were much tougher than LA. For 80/20 road/gravel I'd go with a more road oriented tire set up tubeless. If you have the room on your bike the Conti gets my vote. I bet it will blow up slightly larger than the Roubaix Pro.

David - I spent a couple of years on the 4-seasons in that size. Worked great (I ran them ghetto tubless). Tough as nails - much tougher than my gravel tires (Well, my 40mm ramblers are kinda thin skinned).

Then I got all excited with the GP5000 when they came out both tubeless and in the 32mm size. I'm blown away. Half the rolling resistance of the 4-season (literally), 1-2mph faster on my commute, and amazing in a fast group ride (where I'm drafting and the rolling resistance at 30mph makes a significant difference).

I have traditional and tubeless. The traditional is as fragile looking as any conti race tire. The tubeless is thicker, both in sidewall rubber and the size of the cords (half the TPI means chords twice the size). I can't tell the difference between the two riding, but its clear the TL tire is beefier and more puncture resistant. It seems surprisingly tough. I wouldn't take it on chunky gravel or rough fast gravel down hills - but for the stuff I choose 32mm for, it is amazing.

Its not the toughest or longest lasting, but it seems to be tougher than I expected. Silly fast. The speed may not be anything you notice unless you are really pushing it, but at 8watts/tire at 18mph there is just not that much room for improvement. Its brilliant. Makes me want to try conti's new 40mm gravel tires...

For what it's worth, I feel like the Terreno Dry may actually be faster on pavement than the Zero. The shoulder knobs may put people off, but the tire itself is noticeably more supple. They've been great 80/20 tires for me- though if you're commuting on bad roads the Zero should offer more puncture protection.

You need to step up to 35 mm at least or even 38MM for a good gravel combo.

+1

The Vittora gravel tires are slower than the specs read. They have a heavier casing/sidewall than the competitors. I'd do the Corsa Control over the gravel tires. I'd do a road tire in general unless you have sharp rocks or thorns. I've had good luck with G-One Speed 30c. Another good option with a Challenge Strada Bianci

Unfortunately, this size is still kinds useless on ungroomed dirts, hard packs, and anything with a deformable surface. Forget touching any wet surface. They're fine on proper dirt roads or an excellent trail with a skim of gravel/sand. I wouldn't bother with any knobs - slicks or light tread design only. The problem is that you still need to run these at 60+ psi, so that's not conducive to planned dirt excursions. Running the tires at CX tires pressures is not conducive to road speeds, CX tires are made to cut through mud, and are only that size because the rules require it. If you want both, you need to be on 35c+ tires, ideally around 40c@ 35-40psi to be fast even smooth trails and loose aggregate gravel .Tubeless is the only way to fly here, so you can the the pressure lower. See if you can borrow a 35c tire from someone and if you still have 3mm of clearance on each side (like rear is the issue, or fork crown).

Roadbike.de did a nice roller test of gravel tires https://www.roadbike.de/rennrad-part...eifen-im-test/ and Bicycle rolling resistance did a test of the same tire in various sizes.
Notes before reading these numbers:
-the g-one speed was the heavy duty 100kg build, not the lighter 70kg casing build - the lighter duty build should come in around 18-20w on this test at the same pressure.
-the g-one speed was at 3.5bar 50psi, which is too low for that size
-The road tire was at 100psi and did 17.1 w at 60psi


https://cimg2.ibsrv.net/gimg/bikefor...dd57aa3980.png

From this we can infer with the help of BRR's test that on a similar test on a top end tire:
TT tire @ 100psi - ~10.5w
Top End Road (Pro One TLE) @ 100psi - ~13.5w
High End Road (One TL) @ 100psi - 14.5w
High End Road (One TL) @ 60psi - 17W
Fat road / Skinny gravel (G-one Speed 30-35c w/ road casing) @ 60psi ~ 19W
40C Highend Tire (G-One AllA) @ 50psi - 21.3w

In general:
Gravel knobs only add 1-2w
Heartier sidewalls add 2-3w
Lower pressures cost 3-4w
Thicker primary rubber costs 3w (TT -> everyday use)
A tube costs 1w (race latex) - 3w (std); TL goo costs ~2.5w