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B'Twin Mach 720



Fast and comfortable ride, and cracking Shimano 105 11-speed kit

At every product is thoroughly tested for as long as it takes to get a proper insight into how well it works. Our reviewers are experienced cyclists that we trust to be objective. While we strive to ensure that opinions expressed are backed up by facts, reviews are by their nature an informed opinion, not a definitive verdict. We don't intentionally try to break anything (except locks) but we do try to look for weak points in any design. The overall score is not just an average of the other scores: it reflects both a product's function and value – with value determined by how a product compares with items of similar spec, quality, and price.

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With a punchy ride and fast turn of pace, the B'Twin Mach 720 from French sports superstore Decathlon is every bit as good on the road as its £1,000 specification suggests it is on paper. There are few bikes that offer such good value for money and enjoyable performance.


The Mach's carbon fibre frameset, with its angular lines and sharp creases, delivers a stiff and responsive ride. The frame has clearly been built to be stiff, but B'Twin have sought to balance this stiffness with a dose of ride comfort. The lower half of the frame (down tube, bottom bracket, chainstays) and fork have been built to provide a high level of stiffness, so there are some big profile tubes and plenty of reinforcing material. The top half of the frame is altogether more slender in profile, with skinny kinked seatstays and a tapered top tube that manage to impart a decent amount of comfort into the ride.

Find your nearest Decathlon here

Buy it online here

Does it work? Yes, is the simple answer. The Mach 720 is stiff when you're applying maximum power, with a crisp reaction to your pedalling. Move the bike around on the road and through bends and it feels direct and responsive. The steering provides a good amount of detail, and there's enough feedback through the carbon fork about the road surface to let you push on in earnest without much risk of overcooking it into the corners. Settle down to a steady cruising speed and the Mach 720 impressively soaks up all the vibrations caused by riding over crumpled tarmac and scarred road surfaces.

The Mach 720 is all about going fast. It's very much a race machine, developed with input from B'Twin's under-19 racing team. That explains the short head tube, which promotes a low and aerodynamic position – great if you like getting your head down and pushing on as fast as possible. The top tube is also long, 55cm on this 53cm model, which gives a good stretch to the bar. This would make a great race bike or fast sportive bike, if you ride with an emphasis on fast times rather than a social pace.

Only the slightly high weight of 8.8kg (19.4lb) is a blemish on an otherwise top marks bike. On the flat and over rolling roads it's less of a problem, but you can feel it on the steeper climbs, though fortunately the 11-28 cassette provides some nice low bailout gears for winching your way up.


It has to be said, it's an unusual looking frame. The sharp lines and angles are not to everyone's taste, but I will add that it's a grower; I've come to really like its distinctive looks in the time I've spent with it. The subtle paint job and understated decals work well. And the appearance does mean it fools many people into thinking it's a more expensive bike than it actually is.

The frame is packed with modern details. There's a tapered head tube and fully internal cable routing. One detail isn't very modern though: the external threaded bottom bracket. Most top-end carbon frames have moved to press-fit bottom brackets but a lot of people aren't fans, and the external type is certainly easier to service and less prone to the creaking of a press-fit assembly.

The half-height seatmast is an unusual design. The last bike I can remember seeing it on was the old Trek Madone. B'Twin's reasoning behind it is that the elevated seat clamp frees up the top tube/seat tube/seatstay junction to provide a greater degree of deflection for comfort. Whether it works or not is tricky to say, but there's no doubting the smooth ride the bike offers.

B'Twin claim a 1,150g frame weight; add in a 320g carbon fork and that's a decent weight for any carbon frameset, let alone one costing £1,000 overall. That makes the frameset a good investment: upgrade a few components along the way, some lighter wheels and even a higher spec chainset and cassette when these bits wear out, and you could easily drop a decent chunk of weight from it.


A grand is really the tipping point where we see carbon fibre becoming an alternative to aluminium, the frame material dominant on bikes costing under £1,000. That said, your choices are still very limited, as our 15 of The Best Road Bikes Under £1,000 buyer's guide shows. An aluminium bike still looks to offer the best value at this price, but it's impressive that B'Twin manage to offer such a well-equipped carbon bike for the money.

Even more impressive is that it comes with a predominantly Shimano 105 11-speed groupset. You have to look at carbon road bikes costing several hundreds more to find a similar specification. It's not quite a clean sweep of 105 parts – there's a Shimano non-series 52/36 semi-compact chainset and B'Twin branded brake callipers – but it all works brilliantly, as you'd expect from Shimano, with clean shifting across the 11-28 cassette from the very ergonomic shifters. That cassette combines smartly with the 52/36 chainset (which we're big fans of here at to provide a generous range of gears, low enough to crawl up steep hills and high enough to maintain race speeds. The brakes have good lever feel with plenty of power to easily scrub off excess speed when hurtling down the hills.

The B'Twin own-brand wheels have an aero shaped 24mm-deep aluminium rim, and a claimed 1,760g weight which is pretty good. The wheels feel zippy and stiff when loading up through corners, and the braking surface delivered good results in the dry and wet. The 23mm Hutchinson Equinox tyres provide good grip in the dry and wet and roll well, but at 290g each they're a bit on the heavy side for a race tyre.

The B'Twin-branded aluminium shallow-drop handlebar is a comfortable shape and the stem provides a smart appearance. A generous number of spacers on the steerer tube allows a degree of height adjustment. The inclusion of bolt-in bar end plugs is a really nice touch and ensures the plugs can't accidentally fall out. I'd happily see them fitted to all bikes as standard.

I really didn't get on with the saddle, it's simply the wrong shape for me, so I swapped it out for a favourite for the rest of the test. The seatpost features a two-bolt head so it's easy to get the saddle in the exact position you need it. The Mach 720 even comes with a set of pedals so it really is ready to ride straight from the box or shop.


With its fast ride and smart handling, a mostly Shimano 105 11-speed drivetrain and decent parts package, the B'Twin Mach 720 is an absolutely cracking bike for the money. It easily outclasses other bikes at this price. If you're looking for a fast performance road bike for a grand there aren't as many compelling choices as this B'Twin.


Fast and comfortable ride, and cracking Shimano 105 11-speed kit

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Make and model: B'Twin Mach 720

Size tested: medium

About the bike

State the frame and fork material and method of construction. List the components used to build up the bike.

B'Twin have constructed the frame by taking a similar approach to other manufacturers, in that they have split the frame into two halves. Not literally! Everything in the lower half, the 'Dynamic Structure' - comprising the fork, steerer tube, down tube, bottom bracket and chain stays, is oversized to provide stiffness, while the top tube, seat tube and seat stays form the 'Supporting Structure' and are designed to provide vibration-damping qualities.

Tell us what the bike is for, and who it's aimed at. What do the manufacturers say about it? How does that compare to your own feelings about the bike?

B'Twin say: "All-new bike for 2015. The b'Twin Mach 720 Carbon Road Bike has a SHIMANO 105 11s compact groupset. The Evo power frame is ESR ready. The new b'Twin wheelset adds extra zip to this already rapid bike. A great value for money and highly upgradeable road racing bike with carbon frame and forks."

"This frame is used by the B'TWIN U19 Road Racing Team."

Frame and fork

Overall rating for frame and fork

Tell us about the build quality and finish of the frame and fork?

The appearance of the frame won't win a lot of fans but it's certainly distinctive. Underneath the sharp lines, though, is a frame that nicely combines stiffness and compliance with very engaging handling.

Tell us about the materials used in the frame and fork?

B'Twin say: "Made from Evo Power carbon fibre, it is designed for pure performance, conserving the necessary comfort on the load-bearing upper structure, and with its frontal rigidity lowered by 10% compared to the FACET ESR frame, improving comfort on long rides."

Tell us about the geometry of the frame and fork?

Very much on the racy side of the road bike spectrum, it will reward anyone with a desire to race or who simply wants to ride as fast as possible all of the time. Comfortable when you don't want to flog yourself, though, it's a good balance.

How was the bike in terms of height and reach? How did it compare to other bikes of the same stated size?

Stretched and low at the front, as you'd expect from a bike developed with a race team, so it'll suit those who prefer to adopt quite an aerodynamic race position.

Riding the bike

Was the bike comfortable to ride? Tell us how you felt about the ride quality.

Surprisingly, despite its angular and muscular looking frame, the Mach 720 soaked up impacts and vibrations effortlessly and provided a smooth ride.

Did the bike feel stiff in the right places? Did any part of the bike feel too stiff or too flexible?

No lack of stiffness when sprinting and surging past mates, towing the chaingang along or doing hill intervals.

How did the bike transfer power? Did it feel efficient?

Very good power transfer and there's plenty of stiffness in the frame and components to reward the most energetic cyclists.

Was there any toe-clip overlap with the front wheel? If so, was it a problem?

None at all.

How would you describe the steering? Was it lively, neutral or unresponsive? Well balanced and neutral.

Tell us some more about the handling. How did the bike feel overall? Did it do particular things well or badly?

Quite fast and nippy handling, with the low front end placing quite a bit of weight over the front wheel, which makes cornering a satisfying experience.

Which components had the most effect (good or bad) on the bike's comfort? would you recommend any changes?

The Shimano 105 11-speed shifters and mechs are simply superb. That might not be a 105 chainset, but it works brilliantly, and even B'Twin's own brake callipers offered decent braking and good progressive feel.

Which components had the most effect (good or bad) on the bike's stiffness? would you recommend any changes?

B'Twin have provided a good balance of components that provide a reasonable amount of stiffness without being too harsh.

Which components had the most effect (good or bad) on the bike's efficiency? would you recommend any changes?

I had to change the saddle straightaway, but you might get on okay with it.

Rate the bike for efficiency of power transfer:
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Rate the bike for climbing:

The high weight holds it back from being a mountain goat.

The drivetrain

Rate the drivetrain for performance:
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Tell us some more about the drivetrain. Anything you particularly did or didn't like? Any components which didn't work well together?

The components provided flawless performance

Wheels and tyres

Rate the wheels and tyres for performance:
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Tell us some more about the wheels and tyres.Did they work well in the conditions you encountered? Would you change the wheels or tyres? If so, what for?

An upgrade to some lighter rubber would be good when these wear out.


Rate the controls for performance:
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Tell us some more about the controls. Any particularly good or bad components? How would the controls work for larger or smaller riders?

The handlebar is a good width for the bike size but I had to put a longer stem on to get a satisfactory reach.

Anything else you want to say about the componentry? Comment on any other components (good or bad)

The list of components is extremely good considering the asking price of the whole bike.

Your summary

Did you enjoy riding the bike? Yes

Would you consider buying the bike? Yes

Would you recommend the bike to a friend? Yes

Rate the bike overall for performance:
Rate the bike overall for value:

Anything further to say about the bike in conclusion?

With its fast ride and smart handling, and a mostly Shimano 105 11-speed drivetrain and decent parts package, the B'Twin Mach 720 is an absolutely cracking bike for the money. It easily outclasses other bikes at this price. If you're looking for a fast performance road bike for a grand there aren't as many compelling choices as this B'Twin.

Overall rating: 9/10

About the tester

Age: 31  Height: 180  Weight: 67

I usually ride:   My best bike is:

I've been riding for: 10-20 years  I ride: Every day  I would class myself as: Expert

I regularly do the following types of riding: road racing, time trialling, cyclo cross, commuting, touring, mtb,


David worked on the tech team from 2012-2020. Previously he was editor of and before that staff writer at RCUK. He's a seasoned cyclist of all disciplines, from road to mountain biking, touring to cyclo-cross, he only wishes he had time to ride them all. He's mildly competitive, though he'll never admit it, and is a frequent road racer but is too lazy to do really well. He currently resides in the Cotswolds, and you can now find him over on his own YouTube channel David Arthur - Just Ride Bikes

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