With a design that is focused away from the race crowd, Open's MIN.D frameset is an excellent option for general riding. Balancing low weight with loads of stiffness at the front end and bottom bracket along with a compliant rear end, the frame is perfect for cruising broken roads in comfort and then smacking it up some climbs.
Everything that I want in a road bike when I'm not racing is provided by the MIN.D. My riding tends to consist of heading into the Mendip hills with their steep, tough climbs and riding out to the coast at Weston. The roads are broken, so comfort is key, but the steep climbs mean that I need a stiff and lightweight bike. I also want sharp handling to keep things interesting.
The MIN.D won't ever compete on the flats with today's race bikes with their aero tube shapes, but in all other regards I have found Open's first road bike to be worthy of the 'superbike' moniker. If you're not bothered by the current trend for front-end integration and aero then this is a fabulous option.
My first ride on the MIN.D went straight into the hills, and the combination of stiffness and low weight (Open claims 870g for a medium frame, 335g for the fork) was instantly noticeable. The bike climbs beautifully, rewarding out-of-the-saddle efforts with instant surges in pace.
With the rather low rear end created by the sloping top tube, it can look, at first glance, like a rather upright bike. But the 135mm head tube on this size small keeps things racy should you want to slam the stem like I did. That isn't to say that this is a long and low racer. A 71-degree head tube angle means that the 535mm stack and 361mm reach create a riding position that suits the general purposes of the bike.
While measurements up top create a comfortable riding position, drop down the bike and you'll find a setup that is anything but slack. The rear centre of 405mm and front centre 578mm (measurements from hub centres to BB) with a BB drop of 73mm create a tight wheelbase of 971mm. This is what I think really makes the MIN.D fun to ride, allowing you to flick the bike around both when climbing and through tight corners.
I have had an absolute blast letting the brakes off and flying down the tight, narrow lanes where the road surface, gravel and patches of grass growing though the tarmac often combine to give you only one possible line, with a mid-corner bunnyhop needed to make it through. Having a bike that feels so chuckable and responsive while still being unfazed by bumps results in a lot of fun.
When I wasn't pushing the limits of grip, the MIN.D is a comfortable place to be, cruising along the flats with a very smooth ride quality. Open has incorporated three design features that really help here. First, the continuous seat tube that extends right from the bottom bracket, running for the majority of its length at 25mm where a bike with a 27.2mm seatpost would use a 30mm external seat tube. This is really thin and is one of the advantages to a continuous seat tube as it allows for extra flex just where it is needed.
Joining that seat tube are two incredibly thin seatstays. Again, these add flex to the frame where it is needed, but the main factor affecting comfort is the space for massive road tyres. Open says that you can fit up to 32mm tyres in the MIN.D and the 32mm Schwalbe tyres fitted to this test bike certainly provide plenty of comfort if you want it. Strictly speaking, when mounted on a rim with a 21mm internal width, those Schwalbes actually sat at just under 34mm.
Playing with the tyre pressure is really important with so much volume. For relaxed spins around the lanes I let the tyres down quite a bit, to around 50psi. This gave a feeling of floating over all those harsh road surfaces but it did feel like the tyres were dragging a little when climbing, so I went up towards 65psi when heading into the hills.
Open's designer, Gerard Vroomen, has called this first road frameset the MIN.D for a very specific reason. It stands for minimal design, and while that might make you think that this is a basic disc-brake road bike, there's quite a bit going on when you take a closer look.
First, the basics. The full carbon frame (no, Open doesn't specify what grade of carbon) centres around a BB386 bottom bracket.
The rear end has 142x12mm spacing and the fork uses a 100x12mm spacing.
Vroomen opted for a continuous seat tube, removing the need for a seatpost and clamp. One of the main reasons, beyond the clean aesthetic, is that the tube can be made very thin, sitting at just 25mm in diameter. This, Open says, adds comfort, and I have to say that this is one of the more comfortable road frames that I've ridden.
The seat tube is topped by the minimalist cap that secures the saddle in place. While you need to be really careful measuring your saddle height before cutting it down, you do have a bit of wiggle room with the top cap offering up to 15mm of added height. If you get things really wrong then Open's Measure Once Cut Twice top cap adds 15-35mm of height. (Open has a video to explain it.)
Securing the top cap in place is a small compression system secured by two tiny grub screws. I have to say that I had my concerns about these and still have some reservations about the system. My first worry was that a compression system this small wouldn't hold the top cap and, therefore, the saddle in place. Thankfully, it hasn't budged at all.
My second concern was that on our test bike, the heads of the grub screws are tiny and the metal feels very soft. Open says that the production models use a far harder metal for the screws, but I'd still be careful and as always, use a torque wrench when tightening.
Sorry to those of you who are fans of 140mm disc brake rotors – and I'd count myself in that crowd – but the MIN.D frame and fork are both set up to take 160mm rotors without needing adaptors.
Vroomen says that you gain braking power and extra modulation for just a slight weight penalty, and while I can't say that I've ever had an issue with power from a 140mm rotor, I will concede that I'm on the lighter end of the scale and your more average human will see the benefits of the larger rotor. Not needing ugly mounts is certainly far sleeker.
Open uses the derailleur hanger threads to secure the thru-axle too. It is apparently lighter, and there's not much more to say than that. It secured the wheel as you'd expect.
The frame is set up to accept all electronic shifting systems as well as 1X mechanical groupsets and 2X Shimano R8000 and R9100 groupsets – not 2X SRAM mechanical because it doesn't have the frame stop for the front gear cable, Shimano's is built into the groupset. It's all accessed via a single port on the non-drive side of the down tube, with the SRAM Red eTap AXS build that I have here looking very smart.
Talking of looks, I really like the general aesthetic of this bike: the double triangle design without dropped seatstays and a great rainbow colour fade inside the chainstays.
The MIN.D is only available as a frameset but you can have one built up if you buy from an Open dealer. The world is your oyster, as long as you want an electronic or 1X mechanical groupset, and disc brakes. Seeing as you're spending £3,240 on the frameset, I doubt that's going to present too much of an issue.
And that leads us nicely on to value. At this price we're into the truly high-end part of the frameset market and the competition is tough, but the MIN.D does come in just a little cheaper than another non-aero carbon frameset, Colnago's C60, which is £3,499.95.
The MIN.D isn't marketed as a race bike, but it does compare well with the likes of the Trek Emonda SLR at £3,500 and Specialized Tarmac SL7 at £3,750, although Giant's TCR is far cheaper at £2,349 and boasts an integrated seatpost. All three of these rivals also come with aero claims.
Overall, the Open MIN.D is absolutely fantastic. It balances stiffness with comfort that can really be felt on rough roads. The handling is razor sharp, making this a fun bike to ride both uphill and back down.
Brilliant frameset for fast climbing, and it's comfortable too
If you're thinking of buying this product using a cashback deal why not use the road.cc Top Cashback page and get some top cashback while helping to support your favourite independent cycling website
road.cc test report
Make and model: Open MIN.D.
Size tested: 53cm
Tell us what the frameset is for, and who it's aimed at. What do the manufacturers say about it? How does that compare to your own feelings about the bike?
Open says, 'This is a very different OPEN yet it answers the same question: What do we want to ride? While we love pushing the envelope, we also love the classic bike aesthetic. In the MIN.D. both come together.
'The joy of cycling starts even before the first pedal stroke, as you collect your MIN.D., feel its lightness, admire the sleek tube profiles, see the shimmering midnight blue, smile at the splash of color from the 4 OPEN logo colors fading into each other on the inside of the fork and chainstays.
'Once on the bike, a strange combination of performance and comfort becomes apparent. Every gram of material has a function. Beyond it is nothing, other than the endless draw of roads unknown. This is the MIN.D. (MINimal Design); it exists because it's the road bike we wanted to ride.'
State the frame and fork material and method of construction
Carbon is the material, but Open doesn't specify what kind.
Tell us about the geometry of the frame and fork?
The head tube angle is slacker than a race bike, but the wheelbase is very tight.
How was the bike in terms of height and reach? How did it compare to other bikes of the same stated size?
It is a little taller and shorter than a full-on race bike, but you can still get aero if you want.
Riding the bike
Was the bike comfortable to ride? Tell us how you felt about the ride quality.
It really floats over the rougher roads.
Did the bike feel stiff in the right places? Did any part of the bike feel too stiff or too flexible?
There's a really nice balance between the siffness in the bottom bracket and head tube areas and the compliance in the rear end.
How did the bike transfer power? Did it feel efficient?
It's great. Very stiff down at the BB.
Was there any toe-clip overlap with the front wheel? If so was it a problem?
A little, but it's not an issue.
How would you describe the steering? Was it lively neutral or unresponsive? Lively.
Tell us some more about the handling. How did the bike feel overall? Did it do particular things well or badly?
Fun is the word. If you're looking for stability, this isn't it. It is lively and direct and a joy to ride.
How did the build components work with the frame? Was there anything you would have changed?
I'd have picked Shimano Dura-Ace Di2 over SRAM if I had this kind of money.
How does the price compare to that of similar products in the market, including ones recently tested on road.cc?
At €3,600 (currently converting to £3,241), it's up with the high-end offerings. The S-Works Tarmac SL7 is £3,750 and Trek's Emonda SLR is £3,500, though Giant's TRC Advanced SL is £2,349.
Did you enjoy riding the bike? Yes
Would you consider buying the bike? I like to combine my general riding with racing, so I'd have to pick something that is fast on the flats too.
Would you recommend the bike to a friend? Yes
Use this box to explain your overall score
Lightweight, stiff and very comfortable. It's a brilliant frameset for general riding.
About the tester
I usually ride: Cannondale Supersix Di2 My best bike is:
I've been riding for: 5-10 years I ride: Most days I would class myself as: Expert
I regularly do the following types of riding: road racing, time trialling, cyclo cross, commuting, club rides, general fitness riding, I specialise in the Cafe Ride!
Son of a Marathon runner, Nephew of a National 24hr Champion, the racing genetics have completely passed him by. After joining the road.cc staff in 2016 as a reviewer, Liam quickly started writing feature articles and news pieces. After a little time living in Canada, where he spent most of his time eating poutine, Liam returned with the launch of DealClincher, taking over the Editor role at the start of 2018. At the weekend, Liam can be found racing on the road both in the UK and abroad, though he prefers the muddy fields of cyclocross. To date, his biggest race win is to the front of the cafe queue.