Decathlon B Twin Comp 3 review

Versatile and great value titanium roadie from French mega-chain

Our rating 
4.8 out of 5 star rating 4.8
GBP £1,799.95 RRP

Our review

Super smooth-riding Frenchie that seduces with a combo of quality kit and day-long comfort
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Decathlon’s B-Twin Comp 3 will appeal to those who want a combined sportive, training and even fast commuting bike that’s capable of transporting them at speed over long distances with an emphasis on comfort.


This high-specification, titanium-framed road rig isn’t cheap at a whisker under £1800, though Decathlon’s buying power means it’s still excellent value for money.

Given the excellent kit and the unmatched durability of its core material, it’s the kind of long-term investment even Gordon Brown would sanction.

Ride and handling: easy does it

Swapping an older steel-framed bike for a 21st century titanium and carbon number is a bit like switching from leaf sprung model T Ford to a hydro-pneumatically suspended Citroën luxo-barge. Suddenly you have entered a world of magic carpet, mile-munching comfort and you start to wonder why anyone outside of an elite racer would put up with anything less in a bike.

A titanium frame doesn’t quite have the ‘snap’ that you get in a full carbon frame and this manifests itself in particular when climbing. But that’s not to say titanium becomes a hindrance when you head for higher ground.

On the hilly Tour of Pembrokeshire sportive, the B-Twin got this 12 and-a-bit stone 40-something rider up any number of leg-snapping climbs with unreasonable ease. On a recce for the Dragon Ride, when the time came to let rip on the descents, the bike’s remarkable ability to lock itself on to a line and stick to it whatever the surface, inspired huge confidence, not to mention what was then a lifetime’s top speed (45mph on the descent into Defynnog if you’re interested).

Where the B-Twin really comes into own, however, is in its ability to protect the rider from punishment over the course of one of those big days in the saddle. The much-vaunted ‘springiness’ of titanium is basically a way of saying that it is the metal that soaks up the shocks and not the rider. That makes it a good dry weather option for those who commute longer distances, taking the bone-jarring edge off badly maintained British roads and accepting the occasional hit from a misjudged line over a pothole or sunken drain cover without drama.

If the Comp 3 corners with tremendous stability and poise at speed, then it stands to reason that rapid, twitchy direction changes are not its forte. This is a characteristic that will suit those who want a bike that tracks effortlessly and doesn’t demand a constantly super-alert rider.

Frame: the best of both worlds

Decathlon may not be a label for bike fashionistas, but it’s reassuring to see the Italian tube  manufacturer Deddaciai’s name on the Comp 3, together with a decal indicating the use of 3Al/2.5V titanium.

This material is often referred to as being ‘aerospace grade’. What relevance this has to an earth-bound bike has always escaped us but let’s settle for saying it is has a high strength-to-weight ratio and is extremely corrosion resistant. In common with other metals, however, it can be dented, bent and otherwise broken – it just takes more force to inflict damage.

Being virtually impervious to rust, short of suffering a serious impact there is no reason why the frame will not last a lifetime (no matter how young you are).

The carbon composite seat-stays, chain-stays and forks are obviously a different matter, but given what is likely to be the large production run of the Comp 3, these components should be relatively easy and cheap to replace in the event of crash damage.

Equipment: quality from top to toe

Full Shimano Ultegra SL means you are getting the groupset that’s designed to bridge the gap between standard Ultegra and Dura-Ace. The presence of this kit is itself something of a testimony to Decathlon’s buying power – it’s a velvety-slick, rapid-shifting transmission available here only in triple format (52/39/30) with 10-speed cassette (12-25) and it should provide enough range to tackle almost any incline. On longer, faster descents, speed junkies may find they can out-pedal the top gear.

The Fizik Pave CX saddle, mounted atop a carbon stem, proved a hit with this tester’s bottom, and indeed was cannibalised temporarily to replace the saddle fitted to another, more expensive race bike, for the bruising Circuit of the Cotswolds sportive.

I already use and like Look Keo pedals, so was pleased at their inclusion in the standard package. However, not everyone will appreciate having this decision made for them and thus potentially being left to shift unwanted or duplicate kit.

The wheels are Decathlon’s Allround model, which use bladed spokes (24 up front and 28 at the rear). These hoops feel fast, strong and generally well-matched to the quality of the rest of the bike and have remained true so far.

The Michelin Pro 3 ‘Service Course’ or race-ready tyres are superbly grippy in the dry – you can almost hear the contact patch gluing itself to the road surface as you lean hard into a corner – and they have yet to puncture after circa 400 miles of riding.

The ITM oversize handlebars are wide enough to provide excellent manoeuvrability through slow traffic while allowing plenty of bar-top real estate for gizmos without greatly compromising hand position options. A carbon steerer helps keep weight down to just 8.3kg including pedals for the 57cm version.

Summary: the price is right, and so is the spec

Sooner or later almost every cyclist considers spending a serious amount of cash on a new bike. It’s a daunting prospect as there’s always the worry: “What if I get it wrong?”

But looking at the bigger picture, the Decathlon B-Twin Comp 3 manages to soothe a lot of these fears – big company, economies of scale, no middle man, quality groupset, frame materials of the moment, meaningful manufacturer’s guarantees and even the option of in-house servicing if you live close enough to a store.

When you get on the bike and experience that sumptuous, cosseting ride, that reassuringly stable handling and those smooth, near instantaneous gear-changes, there is even a greater body of tactile evidence laid alongside what your head may have already decided looks like a sensible purchase.

Were it fitted with the clearances, eyelets and braze-ons for a set of racks and mudguards the Comp 3 would add wet weather commuting and light touring (at least) to its already impressive armoury. In doing so it would compete with the likes of the van Nicholas Amazon as quite possibly the ultimate all-rounder.


As it is, we’ve used it for sportive, training and commuting purposes and it has always been a joy to ride. For riders who need a machine capable of any one of these applications this is a sound choice of bike, but for those who want to do all three on a single bike, the rationale for taking the plunge becomes hard to resist.

Product Specifications


Name B-Twin Comp 3
Brand Decathlon

Description Restricted use : cannot be fitted with mudguards or pannier rack.
Rims New b'twin Aero allround
Year 2008
Wheelset Aero
Available Sizes 53 55 57 59 61cm
Weight (kg) 8.3
Stem b'twin aluminium oversize stem
Seatpost Carbon seatpost
Saddle Fizik Pave Sport CX saddle
Rear Derailleur Shimano Ultegra SL 10 speed
Manufacturer's Description Designed for long
Handlebar ITM 300 oversize handlebars.
Front Derailleur Shimano Ultegra SL 10 Speed
Frame Material Dedacciai K19 series 3-2.5 titanium frame. Carbon rear.
Fork b'twin carbon fork with carbon steerer.
Cranks Shimano Ultegra SL group with triple chainring only
Chain Shimano Ultegra
Cassette Ultegra 12/25
Brakes Shimano Ultegra SL callipers.
Chainring Size (No of Teeth) 30 39 52