Mekk 4G Primo SI 5.5 review

Speedy aero road ride

Our rating 
3.0 out of 5 star rating 3.0
GBP £1,999.99 RRP | USD $3,144.00

Our review

Fast aero road bike with a beautifully appointed frame and quality drivetrain. More suited to speed than climbing, though
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New brand Mekk impressed us with the £1,200 Poggio. The Primo SI 5.5 comes in higher up the price range, at the highly competitive £2,000 mark. At this level, value for money still counts but it’s more important for a bike to have an impressive spec and frameset.


At first glance the Mekk scores on both fronts, with a complete Shimano Ultegra drivetrain – about as good as it gets as this price – and branded finishing kit from the likes of Mavic and Ritchey. Designed in Italy and manufactured in the Far East, the frameset is bang up to date too, with aerodynamic lines.

Up front, a tapered head tube blends seamlessly into a deep-bladed aero fork. The deep down tube and seat tube continue the wind-cheating theme, while an oversize bottom bracket shell and deep chainstays boost stiffness for improved power delivery. The frame is completed by a slim top tube and skinny seatstays.

The Mekk has an aggressive ride position, achieved with a combination of a low front end, longish top tube and long (120mm) stem. We like the clean lines and understated graphics, and there are some neat frame features too, like a hidden seatpost clamp and dedicated carbon aero post. Carbon dropouts add to the svelte look.

The narrow aero tubing gives the bike a sharp-edged feel and it responds to rider inputs with immediacy. This responsiveness is only tempered slightly by the stout wheelset and heavy tyres.

The wheels are well built, stiff and use Mavic’s legendarily hardy CXP 22 rims (on unbranded hubs). They’d be fine for commuting or training but they’re a little underwhelming on a frameset as accomplished as this. The same can be said for the Continental tyres. The Ultra Sport is tough and has a decent tread but it doesn’t roll as fast as we’d like.

The Mekk’s ride isn’t the most cosseting and some road buzz makes its way through to your hands, but this is easy to live with. It also isn’t as sharp through the turns as the best of the competition, with a tendency to run wider from the ideal line – something we put down to the low position and long stem. Overall, though, it performed admirably on the climbs and rolling, twisty back roads of our main test route.

However, it was when we took the SI 5.5 for a 60-mile ride around Spalding in Lincolnshire that it came into its own. Tucking into an aero position and stomping on the pedals on the flat, straight Fenland roads, the heavy wheel and tyre package ceased to be an issue once up to speed. The frame’s slippery lines got on with beating the wind and we were propelled along at a rapid pace. We can see a bright future for Mekk if they continue producing bikes of this calibre.

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This bike was tested as part of Cycling Plus magazine’s 2012 Bike Of The Year feature – read the full results in issue 260, on sale Friday 2 March.

Product Specifications


Name 4G Primo SI 5.5 (12)
Brand Mekk

Description Continental Ultra Sport tyres
Brakes ICE
Fork Carbon
Frame Material Carbon
Front Derailleur Shimano Ultegra
Handlebar Ritchey Comp
Rear Derailleur Shimano Ultegra
Rims Mavic CXP 22
Saddle Fizik Arione
Shifters Shimano Ultegra
Stem Ritchey Comp
Weight (kg) 8.2