B’Twin Ultra 720 AF review

Astonishingly well specced alloy

Our rating 
4.0 out of 5 star rating 4.0
GBP £1,050.00 RRP

Our review

An amazing spec and impeccable road manners — I’ll overlook the minor flaws
Buy if, You want one of the best value race bikes currently on the market
Pros: All-round performance, spec
Cons: Rear brake setup
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B’Twin is sports giant Decathlon’s in-house bike brand, and the Ultra AF is its aluminium racer, big brother to the super-affordable Triban series.


The Ultra’s headline selling point is its spec, which is remarkably good, especially compared to some of the competition whose offerings have taken a hammering from unfavourable exchange rates. You get a full Ultegra groupset with no substitutions apart from the chain, and the brakes are the outstanding direct-mount version rather than conventional single-bolt variety.

The wheels are Mavic Cosmic Elites, which retail for £370 a set — these are not the bargain basement rims that bikes at this level typically come with. It doesn’t end there, the saddle is a proper Fizik Arione that’s stylishly colour-coded to the frame and bar tape, and the alloy cockpit and seatpost are basic, but very nicely finished.

All this good stuff is bolted to an aluminium frame that’s distinctly B’Twin in flavour. It has sharply defined lines with a seductively arched top-tube, a design that mirrors that of the carbon version.

I tested a size medium which weighed 8.7kg
There is one fly in the ointment: I wish B’Twin hadn’t chosen to hide the rear brake underneath the chainstays. Although it looks tidy and removes the need for a rear brake bridge (potentially allowing more comfort-giving seatstay flex), this isn’t a bike with any real aero pretensions and doing so makes minor adjustments less convenient.

It also necessitates an awkward inline quick-release at the handlebar end as the brake caliper lacks one of its own, and it places the brake in an area that sees bigger deflections under pedalling loads; with pads set to run fairly close I found that the slightest hint of muck on the rims caused irritating scraping noises as I hauled myself up steep climbs.

The simplest solution is simply to run the pads a bit wider of course, but I shouldn’t really have to. And while I’m on the subject of funny noises, I also suffered a bit of cable rattle over rough surfaces.

This isn’t a bike that wears you down with excessive road buzz by any means
Robert Smith

These minor annoyances aside, the Ultra is an impressive bike. It’s heavier than its more expensive carbon counterpoint, the Ultra CF, but it gives up little in ride quality, striking a very acceptable balance between comfort and verve. The seatpost isn’t carbon and you’ll feel the bigger hits through the back end, but this isn’t a bike that wears you down with excessive road buzz by any means.

The Ultra’s geometry is racy without being ultra-aggressive, with a medium model sporting a 148mm head-tube and a 548mm top-tube. The latter is near-horizontal, meaning some riders won’t have a lot of seatpost on show, but get the sizing right and you’re rewarded with a very capable and well-rounded ride, and an exciting one too — the Ultra rewards whether you’re heading uphill or down.

The Ultegra groupset is as competent as ever too and those brakes really are excellent, despite the issues with the rear noted above.


The Ultra is a precise and confidence-inspiring racer that doesn’t come with the usual caveats about cut-corners on the spec. It isn’t absolutely perfect but however you slice things, it’s an awful lot of bike for the money.

Product Specifications


Name Ultra 720 AF
Brand Btwin

Available Sizes S M L XL
Rear Wheel Weight 1630
Wheelbase (cm) 98.5
Top Tube (cm) 55
Standover Height (cm) 81
Seat Tube (cm) 50
Chainstays (cm) 41.5
Bottom Bracket Height (cm) 27.5
Wheelset Mavic Cosmic Elite
Weight (kg) 8.7
Trail 7.4
Stem B'Twin alloy, 100mm
Shifters Shimano Ultegra
Seatpost B'Twin Competition alloy, 31.6mm
Seat Angle 74
Saddle Fizik Arione
Rear Tyre Mavic Yksion Comp 700x25mm
Bottom Bracket Shimano Press-fit
Rear Derailleur Shimano Ultegra
Headset Type Cartridge with 1 1/4in lower bearing
Head Angle 72
Handlebar B'Twin Competition Ergo, alloy
Front Wheel Weight 1200
Front Tyre Mavic Yksion Comp 700x25mm
Front Derailleur Shimano Ultegra
Frame Material 6061 aluminium
Fork Offset 3.5
Fork Ultra Evo Vario carbon, alloy steerer
Cranks Shimano Ultegra 50/34
Chain KMC X11
Cassette Shimano CS-6800 11-28
Brakes Shimano Ultegra direct-mount
Frame size tested M