You’d be forgiven for not knowing much about Simplon. The Austrian brand started life as a family bike shop back in 1930, with the name Simplon referencing the towering 2,005m Simplon pass in Austria. The brand was the first to bring Shimano to Austria and the first to introduce mountain bikes to its home country, too.
The Kiaro Disc was designed around what the engineering team calls “comfort concept”. This consists of manipulating the hi-mod carbon fibres with the frame to offer compliance where needed and stiffness in critical areas dealing with load – i.e. the head tube for steering duties and the bottom bracket for pedalling forces.
Elsewhere, the tube shapes have been manipulated to offer vertical flex, or what Simplon has monikered ‘Vibrex’.
It’s easiest seen in the top tube, which tapers from a wedge-like profile at the head tube down to an almost flat, almond-like shape in the centre before broadening a little at the seat tube junction.
The junction is designed to allow vertical flex in both top tube and the stays – so the seat tube is designed to allow fore and aft movement.
The seatstays bow with a flattened profile and the compact front triangle leaves plenty of exposed seatpost.
Cable routing is neatly internalised through the headset. David Caudery/Immediate Media
Up front, the fork is slickly integrated into the head tube as a nod to aerodynamics and the cable routing is neatly internalised through the headset and head tube, again giving the bike an aero edge.
The fork is slender in profile and the dropouts, named ‘raptor’ by Simplon, are rear-offset, which means that the fork fibre path is elongated; by offsetting the axle away from a direct path to the rider it lengthens the path vibration has to take thus reducing the fatiguing impact on the rider.
So, while next to the tech-laden Domane and Roubaix, the Kiaro Disc may look simple, there is actually a lot going on underneath the understated skin.
The ride position on my 58cm bike is classic endurance stuff. A 608mm stack is on the lower end of things while the 387mm reach is spot on for comfortable, yet sporty ergonomics. The 8kg weight makes it the lightest compared to the other bikes on test and there are some smart choices on the build, too.
Raptor dropouts reduce vibrations reaching the rider. David Caudery/Immediate Media
The DT Swiss ER1400 wheels may not have the glamour of carbon but the alloy rims are built onto Dicut 240 hubs with DT Swiss’s lightweight 240 internals. The rim itself is tubeless-ready and a 20mm-wide pair would set you back around £800.
They are shod with Schwalbe Pro One tubeless tyres (set-up tubeless) in 28c and they roll superbly and add real spark to the Kiaro, especially on the climbs where the Kiaro outshines the competition.
The slightly forward position, due to the steep 75-degree seat angle means you’re over the cranks and efficiently pushing power through the pedals. The Kiaro rewards hard efforts, especially out of the saddle, and once you’ve crested a climb it’s a confident descender, too.
The Simplon Kiaro Disc offers a comfortable, vibration-free ride. Robert Smith
Equipment wise, the Kiaro can’t quite offer the value for money of Giant’s Defy but there’s nothing here I ever felt the need to change beyond the decent (but not my personal choice) Selle Italia SLR saddle. It’s comfortable enough with generous padding where you need it and the slender profile is a good fit, but the shape is a little flatter than I usually prefer.
That aside, the wheel and tyre package is excellent and puts the more expensive Roubaix Comp to shame, the dedicated carbon seatpost offers a lay-back shape and plenty of compliance.
Up front, Simplon’s ARC1 carbon bar/stem combo is superb, stiff yet compliant over rougher roads with a great shaped drop.
Overall, the Disc is a very accomplished bike. It has a comfortable ride that is beautifully blended to a lightweight package and race bike-like handling.
The downside is that it looks expensive on paper for a bike that’s ‘only’ mechanical Ultegra and has alloy wheels. It’s also quite hard to find in the UK with only a handful of Simplon dealers around.
Simplon Kiaro Disc geometry
Seat angle: 73 degrees
Head angle: 71.5 degrees
Seat tube: 49.3cm
Top tube: 54.5cm
Head tube: 19.5cm
Fork offset: 5cm
Bottom bracket drop: 7.4cm
Bottom bracket height: 29.6cm
How we tested
This bike was tested as part of a five bike grouptest of premium endurance machines.
The bikes were tested against each other to find out which one provides the best blend of comfort and performance.
Bikes also on test: