We’ve tested two Reaction 29ers recently, but both were built around Cube’s GTC carbon fibre chassis rather than the alloy frameset featured here on the Cube Reaction HPA Pro. Don’t be thinking that this puts the HPA at a disadvantage though — in fact, we reckon pure racers might well prefer testing their mettle on, erm, metal.
For a start, while you might expect the carbon bikes to be lighter, they’re not. Although they have similar Shimano XT-based spec and equally light wheels, the GTC Pro is 900g heavier than the HPA and the GTC SL weighs 500g more.
The bikes feel different too. While the carbon Reactions are silky, even with skinny seatstays and triple-butted alloy frame (including a flattened top tube) the HPA is a tauter, tighter feeling bike. It’s also slightly shorter and lower, which bolsters that immediate, agile character. Add in lighter wheels and it will trash any preconceptions about 29ers being slower handling. While long-ride comfort is slightly compromised by the stiffness, the larger wheels still have a clear speed-retaining benefit on rough ground.
That’s helped by the skinny 27.2mm seatpost’s flex, which lets you lay down power from the saddle rather than getting knocked off your rhythm, despite the punchy delivery.
You’re not looking at an obsolete frame on a late retirement ticket either. It is Side Swing derailleur routed and direct-mount rear mech equipped for the fastest, most accurate shifting possible. If you can find a dropper post the right diameter, it can be routed internally down the seat tube and the 142x12mm rear axle uses an Allen key closure rather than a heavier cam lever.
The Reaction HPA Pro comes with a RockShox Reba fork and Magura MT2 brakes Russell Burton
It’s clear then that the Cube is a properly focused race bike, and it’s equipped to match. The RockShox Reba fork isn’t as smooth and fluidly damped as the Fox that you’ll find on the Canyon Grand Canyon, but it matches the frame character and there’s a lockout plunger on the bars.
The Magura MT2 brakes are lighter than most budget options too. As mentioned, the Answer Atac wheels are light for 29ers and the Schwalbe Rocket Ron and Racing Ralph tyres are featherweight LiteSkin versions. That makes them more likely to impact-puncture and harder to set up tubeless though — so use that agile handling to dance around trouble rather than slam into it.
With Cube’s carbon bikes providing a smooth riding, distance-friendly option, they’ve been free to make the alloy HPA a punchy, lightweight and agile racing package that aggressive riders will love. Don’t forget to factor in the invaluable long-term support you get from a proper shop when pricing the Cube against online competition.