B’Twin Ultra 940 review

Can a superstore racer hit the heights?

Our rating 
4.5 out of 5 star rating 4.5
GBP £2,999.00 RRP

Our review

Cutting-edge frame design meets high street value for a winning combination
Skip to view product specifications

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:
Robert Smith

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:
Robert Smith

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.

Product Specifications


Name Ultra 940 (14)
Brand B'twin

Available Sizes XXS XS S M L XL
Weight (lb) 15.83
Seatpost B-Twin
Shifters Shimano Ultegra Di2 11-speed
Stem Deda Zero2 11.5cm
Weight (kg) 7.18
Wheelset Mavic Ksyrium SLR: F 18 bladed spokes, R 20 bladed spokes
Year 2014
Spoke Type Bladed Spokes. 18 Front, 20 Rear
Saddle Fizik Arione
Bottom Bracket Height (cm) 28
Chainstays (cm) 40.5
Seat Tube (cm) 48
Standover Height (cm) 80
Top Tube (cm) 56
Wheelbase (cm) 99
Seat Angle 73
Rear Wheel Weight 1400
Bottom Bracket Shimano Ultegra PF86
Frame Material B-Twin Ultra Evo Dynamic
Brakes Shimano Ultegra
Cassette Shimano Ultegra 11-25
Chain KMC X11
Cranks Shimano Ultegra 50-34 172.5mm
Fork Full carbon
Fork Offset 5
Front Derailleur Shimano Ultegra Di2 11-speed
Rear Tyre Mavic Yksion Pro Powerlink 25mm
Front Tyre Mavic Yksion Pro Powerlink 25mm
Front Wheel Weight 1020
Handlebar Deda RHM02 42cm
Head Angle 72
Headset Type B-Twin sealed, integrated
Pedals Look Keo 2 pedals
Rear Derailleur Shimano Ultegra Di2 11-speed
Frame size tested M