I was lucky enough to take out the two leading carbon gravel bikes from Open and 3T on an extended overnight test at Eurobike. These bikes alongside the Lauf True Grit I tested last year here are the best known super light carbon gravel bikes out there. Focused at going fast with the least effort they are for racing and fill a niche for speed within the adventure bike market rather than the more all round gravel bikes out there.
3T Exploro XL
Open U.P. Medium
So where to start?
3T Exploro new flat mount bike
Bike tested was built with 3T discus C35 carbon wheels, SRAM force hydro groupset that I am used to and 3T carbon finishing kit including the flared 3T Superghiaia Team Stealth bars which are straight for the lever drop and then flare at the bottom of the drops. Interesting to get a decent test on these bars but personally I still prefer the Ritchey Venture max that flare from the top.
I was on the Ltd frame which weighs a mind boggling 990gms in medium and the full matt black.
Why start with the tech when the looks are probably what most people will be swayed by if considering the 3T. Personally I like it, the chunky aero sections proved efficient in testing and look good, on the other hand when I mentioned the bike to a friend they responded “the super ugly one?” I knew they meant the 3T such is the look of it!
There’s no denying this bike rides fast, it’s probably quicker than an e-bike at accelerating! It is all built for speed, with just enough comfort to ensure you can keep coming back for more. It accelerates like lightning but still asks to be thrashed and drifted down rough gravel descents as the chunkiness of frame gives reassurance and bags of stiffness – more than the 990gm weight might give impression of! At 194cm tall an aero gravel frame is the least of my worries but I guess every little helps and it’s probably the distinctive aero look which will sell this rather than the marginal gains.
The geometry changes through the size range meaning my XL was on the steeper head tube range than I would like at 72.5. It rode well on gravel but on techy sections of singletrack in its 650b fat tyre guise I think it’d reach its limit of control quickly however as discussed below the Open is almost identical geometry. The tyre clearance was actually reduced slightly on the fork as they felt it had too much on the original, it still comfortably fits 700x40mm and 650bx2.1″ The aero seat post took a lot of torque to stop slipping, I was nervous I’d round out the horizontal bolt with my old multi tool and obviously it needs a specific seat post to fit.
New Open U.P.
Set up was DT Swiss XM 1501 alu wheels that are a fraction heavier than the 3T but not slow and maybe a tad more comfortable, the finishing kit and SRAM Force groupset was comparable but the 3T had the flared drop bars. It was ridden by Jessie in size medium so not a true back to back test.
Weight is comparable to the painted 3T Exploro but as tested it was heavier due to the 3T having less paint being used – still 1040gms ain’t heavy – the Open U.P.P.E.R. is even lighter though if needed! The first impression is that it’s the same as the original U.P. but it comes with lighter fork and flat mount brakes on the front fork directly and on the rear too like the updated Exploro.
The frame takes up to 700x40mm and 650b to 2.1″ so ticks all the right boxes for clearance. The geometry is pretty much identical to the degree and mm only the stays are 5mm shorter on the Open! Again in XL it would be good to see a fraction less steep head angle at 72.5, but they are both the same.
Again both bikes have the same bottle cage and luggage bolts on the top tube so no winner there.
The seat post is a traditional and reliable bolt on collar for the Open which is a functional choice that I like.
The Open UP can’t be disliked aesthetically; it has sleek looks, effective cable routing and simple colours. The dropped chain stay being the same notable feature to the 3T.
Conclusion
Both these bikes are fantastic and on the face of it the colour and look is what a decision might come down to. However there is more to it than that. The Exploro is stiff and harsher, it also felt faster to accelerate with its marginally shorter rear stays – which we only found out later so the frames do reflect this too when riding. The Open has a subtle bend on the narrow rear stays for compliance, the Exploro has less shape here and uses a wishbone stay, overall it has more material making it less forgiving but aero and as responsive to power in the pedals as an ebike on boost. 
If speed is all important as you rip between gravel and road then the 3T is for you, if longer days and a fraction less of a kick from acceleration then go for the Open U.P. or failing that if comfort is king but the speed of a carbon super bike still appeals then go for the Lauf True Grit. For all the bikes it is not just the crazy light frames but about the wheels as much as the frame and both builds had high quality wheel-sets that match the individual intentions of the bikes which is good to see.