Merlin Cordite SL review

Value road bike sorcery

Our rating 
4.0 out of 5 star rating 4.0
GBP £1,000.00 RRP | AUD $2,249.00 | USD $1,637.00

Our review

Enormous value for money and surprisingly good performance
Pros: All-carbon frameset, component specification, weight
Cons: It can feel a bit choppy over rough surfaces at high speed
Skip to view product specifications

At the time of writing, the Cordite SL is reduced on from £1,499 / $1,648.90 / AU$2,285.98 to the frankly ridiculous price of £999.95 / $1,099.94 / AU$1,524.92.


The secret behind this particular trick is that Merlin is using an old frame design from Ridley — specifically the Belgian firm’s 2008 Helium model — as the basis for the Cordite SL.

Back in 2008, the Helium was Ridley’s lightest frameset, weighing in at a claimed 900g for the medium-sized chassis. The equivalently sized Cordite SL frame is constructed by Ridley but weighs 1,200g, plus a further 380g for the carbon fork.

Some of the features hark back to the time when this Helium design was in its prime, the integrated seatmast being chief among them. Although popular with racers for the stiffness and weight savings they offered, seatmasts like this can be unforgiving (and a pain when it comes to packing your bike for overseas travel). Other features that date the design are the frame’s giant circular tubes (no aero profiling here) and the lack of internal cable routing.

The alloy handlebar and stem are provided by Ridley’s in-house brand 4ZA
The alloy handlebar and stem are provided by Ridley’s in-house brand 4ZA
Robert Smith / Immediate Media

There’s limited height adjustment offered by the seatmast’s cap (so cutting the seatmast to the correct length is essential), but the frame’s 175mm head tube makes it fairly easy to get a position that strikes a good balance between being racy and relaxed.

The handlebar, stem, saddle, wheels and brakes all come from Ridley’s in-house 4ZA brand, while a Shimano drivetrain and Continental tyres complete the spec.

Getting the slick action of Shimano’s Ultegra R8000 shifters and mechs is hardly believable at this price. Admittedly some money has been saved by speccing a 105 cassette, a non-series RS510 chainset and the 4ZA calipers, but the riding experience is mostly coloured by the excellent gear controls Shimano puts in your hands.

My Cordite SL came with 25mm Continental Ultra Sport II tyres (but should be Vittoria Zaffiros according to, which give the bike a sturdy refinement to match its lively but assured handling.

Up front, the 4ZA bar has a good shape and works with the stem to provide ample stiffness, while the fork offers a good level of bump absorption. The rear end transmits power well thanks to flattened but chunky seatstays and beefy chainstays.

Merlin's Cordite SL road bike
Black magic: the Merlin’s ride and specs are incredible for the price
Robert Smith / Immediate Media

When you’re cruising below 20mph, even the generously upholstered saddle can’t disguise the fact that jolts from the road reach the rider. But most of the time it’s not intrusive, just a sign that this frame is firmer than more modern designs with flex built in.

At 25mph-plus, rough surfaces become quite choppy, but the stability provided by the parallel 73-degree head and seat tube angles ensures it’s easy to remain in control of everything.

4ZA’s RC31 wheelset rides quite well, but with only average levels of rigidity, acceleration and weight, they’re neither a racer’s nor a climber’s natural choice.

Braking is acceptable, but lacks the precision and power of Shimano’s calipers, although the 4ZA units offer just about enough room to cram a 28mm tyre in underneath them. A wheel upgrade could lower the Cordite SL’s 8.47kg overall weight as well as increase its speed and would still leave you with a machine costing less than most bikes with lower specs.

Fitting tubeless tyres would improve its ride quality too and give this ‘old horse’ a whole new lease of life.

Merlin Cordite SL specification

  • Sizes: XS, S, M*, L, XL (*tested)
  • Weight: 8.47kg
  • Frame: High-modulus carbon
  • Fork: High-modulus carbon
  • Mech: Shimano Ultegra R8000
  • Shifters: Shimano Ultegra R8000
  • Chainset: Shimano RS510 with 50/34 chainrings
  • Cassette: Shimano 105 11-28t
  • Wheels: 4ZA RC31
  • Tyres: Continental Ultra Sport II 25mm
  • Brakes: 4ZA dual pivot
  • Bar: 4ZA Stratos
  • Stem: 4ZA Stratos
  • Saddle: 4ZA Stratos

Merlin Cordite SL geometry

  • Seat angle: 73 degrees
  • Head angle: 73 degrees
  • Chainstay: 40.5cm
  • Seat tube: 50cm
  • Top tube: 56cm
  • Head tube: 17.5cm
  • Bottom bracket drop: 6.6cm
  • Wheelbase: 990mm
  • Stack: 57.5cm
  • Reach: 39cm

Product Specifications


Name Cordite SL
Brand Merlin

Available Sizes XS S M L XL
Stem 4ZA Stratos
All measurements for frame size tested M
Reach (cm) 39
Stack (cm) 57.5
Head Tube (cm) 17.5
Frame size tested M
Wheelbase (cm) 99
Top Tube (cm) 56
Seat Tube (cm) 50
Chainstays (cm) 40.5
Wheelset 4ZA RC31
Weight (kg) 8.47
Shifters Shimano Ultegra R8000
Brakes 4ZA dual pivot
Seat Angle 73
Saddle 4ZA Stratos
Rear Tyre Continental Ultra Sport II 25mm
Rear Derailleur Shimano Ultegra R8000
Head Angle 73
Handlebar 4ZA Stratos
Front Tyre Continental Ultra Sport II 25mm
Frame Material High-modulus carbon
Fork High-modulus carbon
Cranks Shimano RS510 with 50/34 chainrings
Cassette Shimano 105 11-28t
Bottom-bracket drop (cm) 6.6