Basso Diamante Disc Ultegra Di2

The Basso Diamante Disc can easily slip beneath the radar if you're thinking about Italian superbikes, but if you get the chance to ride one – such as this Ultegra Di2 model – you'll soon realise your error. This is one very refined bike indeed, from the build quality and finish through to the way it behaves on the road. It's class; understated class.

I've ridden quite a few Diamantes over the years and have a fondness for the way that they behave. It's mostly down to the impressive ride quality, but the way the geometry works is important too. It's a quick bike designed for those who don't want to hang about, yet it's not tricky to live with. The handling is balanced and never twitchy, while the whole package works extremely well.

This model is also lighter than the aero SV version I tested, so feels very responsive and nimble. Basso describes the Diamante as a versatile racing bike, and I'd very much go along with that.

The ride quality is excellent even though the Diamante feels a little more rigid than some. That gives it a slightly buzzy feel over poor road surfaces, but in a kind of fun way that makes it feel eager and very involving.

There's a lot of feedback from the tyres, which means the Diamante is a ton of fun in the corners and when descending, but despite the rigidness it stays planted on the road.

Some very stiff bikes can feel a little unsettled on less than smooth road surfaces. They can also give too much feedback, which can make a fast bike actually slower as you have to back the pace just to process all the information. The Diamante strikes a great balance, which means that that isn't an issue here.

I felt like I could really let the Basso go on my downhill test section, and it never felt as though it was getting away from me or needed a dab on the brakes to reign it in.

This stiffness makes the Diamante an impressive sprinter, with no flex whatsoever around the bottom bracket area. The front end and fork resist heavy braking forces well. It's ideal for days in the hills with plenty of long climbs and fast descents.

If you're spending time on the flat then the ride position isn't as extreme as it looks with that slammed front end. The frame geometry balances it all out, letting you get aeroish without needing to have any ribs removed.

The overall comfort is decent for such a stiff bike, helped by some well-chosen kit. This is a bike I could spend many, many hours aboard without issue.

Frame and fork

Basso controls the whole creation process of the Diamante, from the design to the prototyping and the eventual manufacturing of the carbon frame in its Italian factory. The result is a very, very beautiful bike.

This colour scheme leaves plenty of carbon on show beneath the clear lacquer, and while I think it is pretty frame, you also get that engineered look in places – you can see the various carbon fibre sheets, most notably the bottom bracket area.

Like most road bikes lately, the Diamante embraces full internal cable and hose routing, but unlike a lot of others it is compatible with both electronic and mechanical groupsets.

All wires, cables and hoses are directed inside the handlebar/stem and down into the head tube, and only reappear where they are required. That's a bit of a faff to set up, no doubt, but it does make for one very clean-looking machine.

Everything else has also been tucked away, so you get a fully integrated headset, an internal seatpost clamp and a pressfit bottom bracket. In fact, the only things you really see sticking out are the bottle cage mounting points.

The Diamante offers decent clearance, with space for tyres up to 32mm wide. That's not as wide as some on the market, but more than enough for a road bike, in my view.

The Diamante is available in five sizes from UK importer Chicken CycleKit, and Basso claims it's 900g in the 56cm/large. It's 1.3kg for the frame and fork, and 2.15kg for the full frameset as sold, apparently.

The line-up kicks off with the 48cm XS and tops out with the 58cm XL, with corresponding top tube lengths of 515mm to 575mm.

Something about the Diamante's frame makes the bikes look bigger than they actually are, though – at least to me – and a lot of that is the seat tube length. On this 56cm for instance the top tube and seat tube are exactly the same length at 560mm, which is what creates that traditional look – a look that faded away in the mid-to-late nineties as compact frames and sloping top tubes became the norm.

As for the rest of the geometry, the head tube is 155mm long and the bike ships with 15mm of spacers on top. This, along with the top tube and various other bits and bobs, means the stack and reach figures are 584.3mm and 386.9mm respectively.

The chain stays are 400mm long and the distance from the centre of the bottom bracket to fork dropout is 593.5mm. The head angle is 73.1°, and the seat angle is 73.5°.

Finishing kit

This Diamante Disc comes with the latest 12-speed Ultegra Di2 R8170 groupset and, whatever your beliefs about putting Shimano on an Italian bike, you can't deny this is a very good groupset indeed. You need only read our full groupset review to see that.

We have a 50/34T compact chainset fitted here, which ties in nicely with the Diamante's 'versatile' description by giving you a lower spread of gears for the climbs compared to a 52/36T.

The shifting from this groupset is top notch – quick and precise – and I like that it feels slightly heavier than Dura Ace, as it maintains a kind of a mechanical feel. I enjoy the slight clunk of the chain as it passes across the cassette or chainring.

Basically, it can't be faulted for shifting or braking performance, and it does well on value too.

The majority of the rest is made up of Basso's own components, including the carbon fibre integrated seatpost and the Levita Integrated cockpit.

The handlebar/stem comes in a range of sizes per frame size, and it's no surprise to see a 420mm bar and 110mm stem on this 56cm bike. Basso offers 13 variations from 90x400mm to 130x440mm, though, if you need that tweaked.

Assuming it fits this is a very pleasurable setup to use. The slight aero shape to the top of the handlebar gives plenty of comfortable hand positions, and the shallow drop shape isn't too extreme for the less flexible of us to use.

You get mounts to hold your GPS computer, and there's just enough flex in the bar to take the sting out of rough roads without it feeling too soft when climbing hard out of the saddle.

Speaking of saddles, here you'll find a Selle Italia Flite Boost Carbon SF, which I found a pleasurable place to sit. The padding is minimal, which I like, and the cutout helps minimise numbness.

For the wheels Basso step in (or perhaps roll in) again with its Microtech range. The RE 38s use a 38mm-deep carbon rim with an inner width of 23mm. With 24 Sapim CX spokes in each it's definitely a racer's wheelset, and at a claimed weight of 1,560g they are decent on the weight front.

I found them to roll well and work on a range of terrain. They're light and stiff enough to cope with climbing, but give a small aero benefit on flatter sections and descents. You won't need to swap them out on windy days either, as they don't get caught by the breeze. They ran true straight out of the box, and I had no issues with reliability throughout the review period.

On importer Chicken CycleKit's site the Diamante is specced with Continental GP5000 tyres, although ours was fitted with Vittoria Corsas. This happens a fair bit with demo bikes, but whichever of these tyres you get, their performance will match that of the Basso.

We have reviewed many variations of the GP5000s and have always found them among the best tyres on offer for their balance of performance, grip and durability.

Value and competition

This model is £7,199, which looks pretty high against something like Orro's Gold STC Force D2 Etap AXS Tailormade at £4,899.99. But you have to take into account the Diamante's frameset; it's built by hand in Basso's own Italian factory, and that obviously adds a premium over one built in the Far East.

If you must have an Italian bike, Pinarello has released its 'F-Series' of performance-orientated road bikes with similar geometry to the Diamante. The Ultegra Di2-equipped F7 comes either with a set of Most Ultrafast 40 wheels (£7,000) Fulcrum's Racing 500s (£6,500). We haven't reviewed one yet, but we have tested the X3 from the X-Series endurance range.

Overall

The Diamante is a lovely bike to ride thanks to Basso's expertise with the ideal lay-ups and specs of carbon fibre grades. It manages to pull off that firm ride without coming across as harsh, and even turn that to its advantage: the Diamante combines excellent road feedback with a surprising amount of comfort.

Basso may not have the big-name draw of Colnago or Pinarello, but it definitely deserves it... or actually, maybe let's keep quiet. That way it keeps hold of that understated persona to be enjoyed by those in the know.

Verdict

Blends modern performance with traditional styling to stand out from the crowd – and it's a joy to ride