66 mm tyre clearance: OPEN closes the gravel frame WI.DE. 2.0 closes the gap to the MTB

Ten years after the launch of its first performance gravel bike, OPEN is opening a new chapter. With the WI.DE. 2.0, the Dutch manufacturer presents a bike for extreme terrain that accommodates tyre widths of up to 66 millimetres. Competition for mountain bikes?

The Dutch frame manufacturer OPEN presents the second generation of its gravel bike for difficult terrain, ten years after introducing the U.P., one of the first performance gravel bikes. While the U.P. model series is designed for fast riding on gravel terrain, the WI.DE. is aimed at riders who also want to tackle very rough and technically demanding terrain.

Tyre widths for mountain bikes

The key feature of the new development is its compatibility with tyres up to 700x66mm (29x2.6"). Compared to 50mm tyres, this almost doubles the air volume, which enables lower pressures for better grip or additional protection for the rims. Integrating this tyre width into a compact frame posed a challenge for the developers - but according to the manufacturer, the result is even slightly lighter than its predecessor.

The trick with the chain stays

Open's biggest technical innovation is the striking, downwardly offset chainstay on the drive side behind the bottom bracket. Why? The challenge was: You want short chainstays for agility, but you need space for wide tyres and the crank/chainrings. The solution: By lowering the stay, the narrowest point between the tyre and chainring is bypassed. The effect: Open manages to keep the chainstay length very short, shorter than on many endurance racing bikes. This should ensure that the bike feels extremely lively despite the thick tyres.

By concentrating on modern gravel drivetrains and dispensing with older configurations such as 2x drivetrains, the available space for tyres and chainstays has been further maximised.

The new U-Turn AC/DC+ fork combines aerodynamic properties with transport options. It has integrated cargo slots for the direct attachment of bags as well as optional mounts for bottle cages.

Extended transport capacity

The WI.DE. 2.0 offers various mounting options for luggage: in addition to the fork slots, there is direct frame bag compatibility and two storage compartments in the down tube with Fitlock fasteners. Additional threads under the bottom bracket and on the top tube make it possible to mount additional bags.

The delivery of the Open WI.DE. 2.0 is planned for the summer. Orders should be possible from mid-May.

Conclusion

With the WI.DE. 2.0, OPEN pushes the boundary between gravel bike and mountain bike even further. The combination of XXL tyre clearance, aerodynamic cargo fork and agile road geometry demonstrates a new development approach. Whether the concept catches on in the market depends on how large the target group is of those who actually venture into such demanding terrain on a gravel bike.