B’Twin Ultra 940 review

Superstore-bought bikes rarely live up to the ‘super’ part of that tag. They’re usually re-branded off-the-peg machines at bargain basement prices – and with no more desirability than a loaf of sliced white bread.

And then there’s this B’Twin from the French sporting outlet Decathlon. This is no cheapo bike-shaped object – the Ultra is as high-tech as anything you’ll find in your local bike shop, and with truly exceptional kit for the price. Surely something’s got to give?

• Highs: Incredible value, superb kit, great braking, understated looks and a top quality all-round ride
• Lows: That braking does come at the expense of rapidly wearing brake pads
• Buy If: You’re looking for an aggressive smooth-riding race bike that’s packed with value

That component list certainly takes some beating. Ultegra Di2 us as good as Dura-Ace with only a small weight penalty, while Mavic’s Ksyrium wheels are exceptionally light. In short, it’s the sort of spec you’d expect to see on a bike easily costing a thousand quid more. Of course, it could just be a case of papering over the cracks if the frame supporting the kit doesn’t do it justice. The Ultra, thankfully, does.

The Ultra has a shortish head tube and is Di2 ready

At the Ultra’s heart is a chassis loaded with up-to-the-minute technology and one that’s seriously light: the frame, fork and seatpost weigh just 1200g in total. It features full internal routing for mechanical or electronic shifting systems and has the latest Shimano direct-mount brakes on the fork and beneath the chainstays, tucked in behind the bottom bracket. The geometry is race specific with a shallow head tube, but the Ultra still has enough nods to comfort to make this worth considering if you’re an endurance rider.

As with the the geometry the gearing is also aimed towards racing. But all this apparent aggression is balanced by the wheelbase, which at around a metre prevents the Ultra from getting too twitchy when you’re out on the road. Push the Ultra through a tight set of bends on a fast descent and it flows with ease. It always feels composed, but reacts to your inputs instantly and is never unstable on the limit – a neat balancing act.

The Ultra’s racy geometry and gearing is nicely balanced by a long, stable wheelbase

Over rough surfaces the rear end feels compliant and smooth, though the front end is a little firmer, the straight-bladed fork and the stiff bar and stem combo transmitting a little buzz to your hands. It’s not fatiguing, but is still noticeable.

The Ksyrium SLRs match the bike’s stealth looks and its build quality. They’re stiff, light and flex free and will help your climbing even with the 11-25 cassette. Mavic’s file-patterned Exalith braking surface improves stopping power in the wet and dry – and though this is accompanied by a wasp-like buzzing, the Shimano direct-mount brakes help to keep this to a minimum. You will still get some serious screeching under sudden braking, though, and significantly more brake block wear – which can get expensive. Tyres are Mavic’s range-topping Yksion Pros – soft, gummy and grippy on dry roads, and in a welcome 25mm width.