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Open MIN.D. 2020



Brilliant frameset for fast climbing, and it's comfortable too
Excellent balance of stiffness and comfort
Not the fastest on the flat

At every product is thoroughly tested for as long as it takes to get a proper insight into how well it works. Our reviewers are experienced cyclists that we trust to be objective. While we strive to ensure that opinions expressed are backed up by facts, reviews are by their nature an informed opinion, not a definitive verdict. We don't intentionally try to break anything (except locks) but we do try to look for weak points in any design. The overall score is not just an average of the other scores: it reflects both a product's function and value – with value determined by how a product compares with items of similar spec, quality, and price.

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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.

The ride

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.

> Buy this online here

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.

2020 Open Cycle MIN.D. - riding 2.jpg

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.

2020 Open Cycle MIN.D. - riding 3.jpg

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.

2020 Open Cycle MIN.D. - riding 4.jpg

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.

2020 Open Cycle MIN.D. - top tube detail.jpg

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.

2020 Open Cycle MIN.D. - seat stays.jpg

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.

2020 Open Cycle MIN.D. - tyre.jpg

Frame and fork

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.

2020 Open Cycle MIN.D. - full bike 1.jpg

First, the basics. The full carbon frame (no, Open doesn't specify what grade of carbon) centres around a BB386 bottom bracket.

2020 Open Cycle MIN.D. - bottom bracket.jpg

The rear end has 142x12mm spacing and the fork uses a 100x12mm spacing.

2020 Open Cycle MIN.D. - fork.jpg

Seat tube

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.

2020 Open Cycle MIN.D. - rear.jpg

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.)

2020 Open Cycle MIN.D. - saddle 1.jpg

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.

> How to set your saddle height right

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.

Smartmount 160

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.

2020 Open Cycle MIN.D. - rear disc brake.jpg

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.

Thruthreaded dropouts

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.

2020 Open Cycle MIN.D. - rear mech.jpg

Internal routing: electronic and 1X mechanical

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.

2020 Open Cycle MIN.D. - cable routing.jpg


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.

2020 Open Cycle MIN.D. - seat stay detail 1.jpg

Build options

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.

2020 Open Cycle MIN.D. - drivetrain.jpg


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.

> Buyer’s Guide: 25 of the best production frames  you can build into your dream bike

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

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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.

Overall rating for frameset

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.

Rate the bike for efficiency of power transfer:
Rate the bike for acceleration:
Rate the bike for sprinting:
Rate the bike for high speed stability:
Rate the bike for cruising speed stability:
Rate the bike for low speed stability:
Rate the bike for flat cornering:
Rate the bike for cornering on descents:
Rate the bike for climbing:

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.

Your summary

How does the price compare to that of similar products in the market, including ones recently tested on

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

Rate the bike overall for performance:
Rate the bike overall for value:

Use this box to explain your overall score

Lightweight, stiff and very comfortable. It's a brilliant frameset for general riding.

Overall rating: 9/10

About the tester

Age: 24  Height: 177cm  Weight: 62kg

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!

Add new comment


iso2000 | 3 years ago
1 like

Hello Hambini fans!

roadrunner23 | 3 years ago

The whole cut to length seatpost thing is a big turnoff. Cut too much off and you have to live with it for ever. The standard post and clamp may add a few grams but allows for infinite fine adjustments. For 3.5k i'd want something much better looking.

Nick T replied to roadrunner23 | 3 years ago
1 like

Usually when a manufacturer specs an ISP they use a seat tube with a recognised internal diameter and extend it up, so you have the option of cutting down and using a regular post and clamp. Been a while since I saw any 22mm seat posts but you might find a kids bike or something with one you can shim to fit somehow. Minimal Design

matthewn5 | 3 years ago

It just looks terribly dated and average, I'm afraid. And a 71 degree steerer? That's slack.

Nick T replied to matthewn5 | 3 years ago

Honestly can't see what this has to justify spending the money on it, there's no special material or construction, doesn't "make you faster", there's no romance of being handmade by Italian artisans, it's just a reasonably light endurance frame that looks reasonably average. Is "designed by Vroomen" that big a selling point? I'd avoid anything the guy touches seeing as his frames tend to fall apart before your eyes, there's nothing here you don't see in any of the Chinese open mould catalogues

Nick T | 3 years ago

Comparing this nonsense to a C60 is mind boggling, but anyway the C60 was discontinued 3 years ago and was never £3.5k, while the replacement C64 starts at £4100

CheshireCat | 3 years ago

A press fit bottom bracket and you can't use a standard seat-post, oh, and it's only any good going up hills...let's not even start on the price.

Blackthorne replied to CheshireCat | 3 years ago

Was going to say this bike comes so close to perfect but what, press fit bb?? Why???? First, saying that 160mm rotors justify a slight weight penalty then not having threaded bb? It beggars belief why we keep seeing this 'feature' endlessly churning out of factories and foisted upon intelligent consumers who are paying the price as a result. Even 2 of the big 3 bike companies have ditched it. One would expect Open to be on the more progressive side of things.   

sparrowlegs replied to Blackthorne | 3 years ago

In technical terms, the pressfit bottom bracket is better than the threaded (which is still a pressfit really). It's just most manufacturers can't get the tolerances correct. The fact Specialized and a few others have dumped pressfit is more an admission that they have crappy quality control and don't employ the correct factories to build their frames.

Have a look at Hambini's video of the OPEN frame he worked on and he said the chap who scanned the frame said it should be condemned and not ridden at all. Also, OPEN refused to warranty the frame when it was proven the bottomn bracket tolerances were way out of spec. So, crap build quality, crap support and extremely high prices. Yep, Vroomen has basically carried on at OPEN where he left off at Cervelo.

You can get a C64 for the same money if you shop around and even if you can't I'd sooner have a second hand C64 than this.

Nick T | 3 years ago

So it's sort of a Defy with an extra 0 on the end, cool

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