A pure-bred time trial bike is great if you have a big enough shed/garage and deep enough pockets, but it’s a single-purpose machine. The Cube Aerium Pro is designed for riders who are getting serious about TTs or triathlon, but can’t justify a bike that only gets wheeled out every other summer Sunday.
Many riders simply fit bar extensions to a regular road bike, and at first glance that’s what the Cube looks like, with its conventional drop bar and clip-on aero bars. Look closer, though, and you’ll see Cube have pushed this bike further into TT territory with internal cable routing to reduce turbulence, the seat tube shaped to hug the rear wheel and reduce drag, and a skinny aero seatpost.
The Cube also has unconventional geometry. Most road bikes have a 73-degree seat angle, while your average TT or triathlon frame tips the rider further forward with an angle of 76-78 degrees. Cube have split the difference with 75.5 – steep enough to open up the angle between legs and torso when in an aerodynamic tuck without making you feel like you’re pedalling standing up when riding on the tops.
So, is the Cube a serious rival to purebred TT bikes? First impressions were positive. There’s no doubt the triple-butted 7005 aluminium frame has been built to handle some serious power. It takes a big, powerful and determined rider to get any flex from the bottom bracket.
The Cube nailed big hills, thanks to its efficient frame and light wheelset. The comparatively wide (44cm) conventional bar and long top tube mean there’s plenty of room to move around out of the saddle, and the 28-tooth sprocket helps too, though it won’t see much use on flatter routes and makes for some jumps between ratios.
Unlike most TT bikes, the tighter and twistier the terrain, the more the Cube likes it, flying through bends, its Schwalbe Ultremo ZX tyres sticking to the road’s wet, gritty surface. But its wings were clipped on faster rolling roads. Every gear change on the Cube means moving out of the tuck position. With practice it gets quicker and smoother, but it disrupts the airflow and your rhythm.
The Cube isn’t as stable as a dedicated TT bike on the extensions either; it’s not nervous, but it needs that bit more concentration to hold a straight line, especially with your weight shifting with every gear change. It’s also fairly unforgiving over rough surfaces, which is particularly noticeable when crouched low over the thin, hard nose of the Selle Italia saddle.