Chapter2 has revealed its top-tier aero road UCI-approved Koko frameset which features Kammtail sections for aero gains as well as an adjustable compliance dual-position seat clamp which is said to allow riders to dial in the ride feel they’re after.
“The Koko might be the fastest, most comfortable aero platform available,” Chapter2 reckons.
Chapter2 has transferred over the aero credentials of its Rere race bike to the Koko, with the brand’s latest aero model featuring Kammtail profiling that’s been incorporated into the down tube. This is claimed to increase the stiffness of the bottom bracket and head tube by 13.35% and 35.64% respectively.
The down tube is said to have been shaped to ensure air flowing from the front wheel is managed to reduce drag.
“Kammtail is a phenomenon where an airfoil’s tail is truncated at a sharp angle whereby the air continues to flow as if the Airfoil is still whole,” Chapter2 explains. It's something that's used to reduce drag on many aero bikes.
“A pure Airfoil profile is long and narrow, not structural[ly] efficient at resisting the lateral forces applied to a bicycle frame via the handlebars and pedalling action,” Chapter2 continues. “A truncated Kammtail profile offers the best of both worlds - an aerodynamically efficient section that also provides the stiffness needed to deliver great performance”.
The front triangle of each size is moulded using a one-piece latex mandrel which, according to Chapter2, ensures the pre-preg carbon wall thickness and resin flow is carefully controlled during production.
Chapter2 says that high-tensile directional Toray carbon has been used in this area to increase torsional stiffness.
The Koko is specced with Chapter2’s aero-optimised Mana bar.
To help with aerodynamics and to provide a clean finish, Chapter 2 has integrated the cabling and hydraulic hoses.
Quick-fit spacers are also included for easy adjustment of the bar height and quick disassembly if packing away in a bike bag for trips abroad.
What’s most interesting about the Koko is its adjustable compliance thanks to its dual-position seat clamp which is designed to allow riders to tweak the ride quality to suit their needs.
“By installing the seat clamp in the lower position, the increased cantilever action of the seatpost will increase the compliance by up to 8.5% allowing the Koko to glide over rough road surfaces and keeping you fresh when you decide to go solo,” claims Chapter2.
If you have the seat clamp in position one, which is facing upwards, Chapter2 says this sets the compliance to ‘normal’. “In this position, the Koko will still glide over any road chatter with ease providing you with the confidence to go full gas,” the brand claims.
It’s when you put the seat clamp face down in position two that you can obtain the benefits of the ‘optimised compliance’ setting. “In this position, the Koko will be able to handle even unsealed rough roads without missing a beat,” Chapter2 says.
The seatstays and seatpost are also designed to damp vibration and you can fit tyres up to 32mm wide.
The frame weighs a claimed 1,139g (size medium), the uncut fork is said to be 420g, the seatpost 135g (medium) and the Mana handlebar/stem 395g. All of these weight claims are to +/-3%.
Koko is available in two colours, Gloss Black and Cobalt with Green.
The Black frameset costs £3,199, while the detailed Cobalt with Green is £3,349.
The Mana handlebar/stem is being sold separately and will cost an extra £619.