I talk in depth with Chapter 2 Bike’s founder Mike Pryde about their top line aero-race bike – the KOKO – which is also the latest PEZ project bike build. Below I go through the full build spec featuring Shimano Ultegra Di2 groupset, Chapter2 HETI C45 aero carbon disc wheels, Mana integrated one-piece handlebar, Arundel cages and bar tape, and Scott Tofino saddle.
Click Play to roll the video – and see more at the PEZ Youtube channel here.
And now for a closer look at the build…
It all started with my unboxing a while back…
Out of the box, it’s easy to see this frame was meant to cheat the air. The seat tube is shaped to snuggly fit around the rear wheel and pass air around it to create the least amount of drag, where the wheel is close to the frame.
The KOKO is Chapter2’s aero race road frameset – currently priced at $2849US for the frame & fork. That’s a good price for a frame like this.
The downtube really shows off the truncated Kam-tail design, allowing for reduced drag while creating the stiff backbone of this frame – that extends from the head tube down through the bottom bracket and along the chain stays to create a very stable platform for the drive train, and to resist the sideways torque caused by pedalling.
The wheelset is new from Chapter2 – their REHI C45 carbon disc wheels – 45mm rim depth and a nice match to the aero-designed KOKO.
The strait fork blades are also individually shaped like airfoils – wider at the front, then tailing narrower at the back. This photo also shows the width of the downtube at the bottom bracket, which really helps create a very stable drive platform. Also note the pointed leading edge at the top of the seat stay – designed to slice the air and reduce drag – it’s a nice detail.
Some quick facts on the wheels: Shape and design is Chapter2’s own, and they oversee production at their partner supplier in Asia. They use Sapim X-Ray spokes (never a bad choice).
But what I really like is the wide 21mm internal width that allows the tire to seat more openly to the rim bed, which in turn allows a more natural – and effective – contact shape to tire, leading to overall better grip, stability, control and performance.
This image from the Chapter2 website gives an idea of how air flows around certain points on the frame.
The airfoil shape is also used on the seat stays, a little hard to see in this photo, but they too are shaped like mini airfoils. This photo also shows how closely the rear wheel is snugged into the seat tube to create the least amount of dragged in this area.
And while we’re looking at the seatpost – check out their seatpost wedge – designed to offer variable stiffness options. The wedge itself has two bumpers – one at each end, and each of a different density (one stiffer, one more compliant). You can tune the amount of seatpost flex by choosing which way you insert the wedge. For example, inserting the wedge with the softer bumper on top, allows for more seatpost flex, thereby giving a more comfortable ride. Insertion the other way reduces seatpost flex and offers more direct road feedback to the rider.
The system is a bit finicky to install, but I did it without much trouble, and once it’s set, you can forget it until it’s time to change the Ultegra battery housed in the seatpost – should that day ever arrive.
The Koko frameset evolved from an earlier version frame set called the Rere (I reviewed it here), one of the upgrades for this new frame is increased clearance for both front and rear tires to accommodate riders’ current choices of wider, higher volume tires for more comfort. I’m running 28 mm Pirelli tires on this one.
The frame is designed with lots of tire clearance. I’m running 28mm Pirelli P-Zeros, but there’s room in there for 32mm tires.
The cockpit features Chapter2’s own MANA integrated carbon one-piece handlebar– which you can buy on its own to mate with any frame. Priced at $499US, it is not inexpensive by any measure, but it is one of the less costly carbon one-piece integrated bar/stem combos out there, making it a solid choice for anyone ready to up their game to go fully integrated.
Internal channelling is slick and coupled with the internal cable routing in the frame sets up for a super-clean and sleek looking build – there’s not a cable in sight.
Across the top the bar features a wide platform, which from an engineering perspective provides a larger surface area to connect to (ie: hold on to), and also dissipate road feedback – which should make for a more comfortable ride on long days.
The groupset is Shimano Ultegra R8100 Di2 12-speed – it’s been well reviewed around the web, and in short is top line, wonderfully though out and functioning gear. Improvements in this latest iteration of their “second tier” wireless cockpit, include more refined braking control, and they say their “fastest shifting ever”.
Note that I put “second tier” in quotes up there, to call out not that it’s one level below their top line DuraAce gruppo, but because anyone who’s ridden Ultegra in the past knows that it’s pretty much as good as any other brand’s top-tier gruppo.
Shimano has pretty much set the bar for technical perfection when it comes to bike gear, and I can’t think of any reason why you wouldn’t be happy riding it.
I’ll start with the levers, since this is the most important point of contact, and the parts of the groupset you’ll look at most. Ultegra first appeared in 1987, with the name an amalgamation of the words “ultimate” and “integrity”. The shape and functionality has evolved considerably since then.
This version hits all the modern design hot ponts – like ergonomically shaped hoods that offer multiple secure grip-points. The levers now control both shifting & braking – with the latter being fully hydraulic.
Shifting is wireless, and controlled by the two paddles tucked in nicely behind the brake lever, and are fully customizable via the Shimano E-Tube app. I have mine setup to control the front derailleur from the left side, and rear gears from the right side, but you can set these to your own preference, and also choose which paddle shifts up or down.
Paddle shapes have been refined to be slightly larger that previous versions, to allow for easier reach from the drops, and also more tactile feedback.
The app also offer customizable shift speeds (although I’m not sure why anyone would want anything slower than the fastest setting possible…), other fine-tuning opitons and connection with other 3rd party computers.
Drive Train
Shimano calls it their “proven HYPERGLIDE+ drivetrain technology”. And they are not wrong – modern design and production technology really is a wonderful thing, with proof right here in how quiet and smoothly this system handles gear changes under a variety of pedalling conditions.
People talk about how expensive the topline Dura-Ace Di2 kit is, but Ultegra has always been the smart buy because it delivers almost the same level of technical perfection as DuraAce, but at about 2/3rds the cost (ymmv) – and I challenge anyone reading this to discern any notable differences in performance between the two gruppos.
The rear derailleur – officially called RD-R8150 Rear Derailleur is compatible with 11-30, and 11-34T cassettes. Shifting performance is excellent, but what really impressed me was the simple charge port located at the back of the derailleur behind a small secure door/ flap.
Unlike other electric systems I have on hand with a poorly designed microscopic connector port that are nearly impossible to see if you’re eyes are over 50+ years, or a system that requires battery removal to charge them, the Shimano system is truly plug & play. The system comes with a usb charging cable that plugs right into the rear derailleur – and blue light comes on to show it’s charging, and when it’s ready the light turns green. So simple.
The battery lives in the seatpost, and is wired to the front & rear derailleurs.
The R8100 brakes use Shimano’s SERVO WAVE technology that allows “a faster initial bite point followed by a wider control area”. Bottom line is better modulation – that’s better feel for how the brakes clamp down on the rotors.
The brake calipers are said to now deliver quieter braking. Anyone who’s ridden disc brakes will by now know that braking noise can come up in a variety of forms – like squeaking pads, impacted by wet or dry conditions, warped rotors, or even not enough pad clearance. Shimano says these now have “a 10% increase in pad-to-rotor clearance to reduce noise”… which sounds good to me.
Maintenance has been made easier too, with a separate bleed port and valve screw simplifies the bleeding process, so you (or your mechanic) no longer have to remove the caliper from the frame to bleed the system.
I opted for 11-34 gear (50/34 up front) which is actually the widest range on a road bike I’ve ridden – but as i’m into my early 60’s age-wise now, I’ve lost the will to push big gears just to prove I’m tough, and settled into some comfort knowing I can still ride up any grade around my hilly home here in Vancouver.
Arundel makes one of the cleanest cage designs around – and they’re good guys too and have have been long time supporters of PEZ. If you haven’t already, check out their website and treat yourself to something designed right and priced for real riders.
The Scoot Tofino saddle is a modern shaped (ie: shorter – nosed) saddle that offers some functional add-ons, with bolt-on accessibility for a proprietary light, fender, and saddle bag that all snug up underneath. It’s a smart little system, and I like how the light fits up right under the saddle placing it as high as possible on the back of the bike, and eliminating the need to strap one on top the seatpost.
For this post I wanted to focus on just the build, and will talk about the ride of the bike later on.
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