The idea for the bike started as Alex’s main engineering project and became a brand after he discovered it was possible to produce frames at a competitive price locally.
The AC1 is a tough bike with 172mm of rear wheel travel, a 63-degree head tube angle and compound wheels. Effigear takes care of the 10-speed gearbox, which uses a SRAM shifter and stock chainring.
As it stands, the mid-size bike with a more budget-friendly build weighs 17.6 kg (38.8 lb) and is expected to cost $7,500 CAD. The AC1 will be available in the fall of 2023 via their website, but aims to be sold to dealers by the end of the year.
• Reynold 853 steel frame with double face
• 172mm travel / 170mm fork
• 29″ or mixed wheels
• Effigear Mimic gearbox
• 62.1° head tube angle
• 79º seat tube angle
• Chainstay: 435mm (454 when sag)
• Weight: 17.6 kg / 38.8 lb (490 frame)
• Dimensions (range): 445, 460, 475, 490, 505mm
• Price: $7,500 – $11,500 CAD
• Frame kit: $5,750 CAD with gearbox and shock
• archibaldcycles.com
The flex points of the rear triangle and hardware junction were carefully analyzed and tested on the trail.
Frame details
The AC1’s Reynolds 853 dual-zone tubing reminds me of a simple bike drawing, although there are plenty of machines that run low on the frame. In the belly of this beast are two components that are dedicated to the design, a lever-actuated shock absorber and a gearbox. Overall, the 490 frame weighs 4.5kg (10lbs) without the shock and comes with a lifetime warranty.
The multi-link, high-pivot suspension design uses a steel rear triangle and Enduro bearings in all but the drop-joint, which contains a bushing. Ironically, Alex was working on his design at the time Trinity MTB was building a similar framework. The Archibald frame is not as adaptable to different drivetrains as the Trinity, but uses far fewer bolts. The rear triangle only has room for a 27.5” rear wheel and does not contain any geometry adjustments.
For the hardware that is used, there is a combination of steel and aluminum. 6mm hardware is used across these pivot points except for the main hinge which is 8mm.
The frame with a clear finish is a second generation prototype and closely mirrors the final product. Sleeker hardware is used on the rear triangle, an upper chain guide has been added, and the idler wheels run with much less noise and drag.
Gearboxes are a highly debated component choice, and for good reason. They are a slightly heavier and less efficient system than a traditional derailleur drive system, but they also offer serious advantages. For starters, they’re less susceptible to shock. Effigear even backs its products with a 5-year warranty.
There’s also the argument for less maintenance as they run in an oil bath, plus you have the ability to shift without pedals. You actually have to let off the gas to shift, like a manual transmission car. This requires reprogramming your brain as you have to turn the pedal for the derailleur to shift gears.
Effigear’s Mimic 469% Range Gearbox features a SRAM 9-speed shifter, which is much more familiar than the twist-grip shifter. To accommodate the upshift release on the trigger, Effigear uses a spring housing that is attached to the down tube.
The Mimic gearbox runs a standard sprocket bolted to a custom freehub carrier and includes a chain tensioner. 142mm wide caps give a narrower overall width for a heel hub, while the single speed hub offers the same wide spoke clamping angles as the 148 Boost hub.
Suspension details
The AC1 falls into the high-spin suspension category, but uses a multi-link design, commonly referred to as an inverted 4-drum, where the chainstay effectively moves between the rear axle and the rocker link. This method allows frame designers to further separate braking and pedaling forces by selecting an optimized idle position. In this case, Archibald has placed the idler behind and lower than the main pivot for full rear travel of the axles.
The CNC aluminum rocker link wraps around the gearbox to produce 172mm of vertical travel at the rear wheels and 32mm out back. A shock with a length of 230×65 mm gives a linear-progressive leverage of 39%, which necessitates the use of a spiral shock. The amount of progression increases towards the end of the journey.
Due to the choice of gearbox drive, only one freehub tooth is required. This keeps the anti-squat stable throughout the travel without accounting for the rider’s weight distribution. Given that high, consistent number and geometry, Alex didn’t say exactly what that anti-squat number is, but he doesn’t see a need to block.
Geometry
If you’re going to build a high-revving steel enduro bike with a gearbox, you might as well take advantage of its power by going downhill. The AC1 has a 63-degree head and short 435mm chainstays (on sag).
However, this does not mean that the rider will be distorted for climbing. The steep 79 degree seat tube angle and consistent anti-squat are said to keep the center of mass well stabilized in the middle of the bike.
As for sizing, there will be five frame sizes, the nomenclature of which is a reflection of the range. The smallest frame starts at 445 reach, increases in 15mm increments to 505mm, and all use the same chainstay length.
Prices and specifications
Archibald’s steel frames will be welded and built into entire bikes right in Delta, BC. Two color choices, matte black or clear, machined finish are available for the frame kit or full build.
Three build kits will range in price from $7,500 CAD to a “Maxed Out” $11,500 CAD component list. Each kit uses the OneUp Dropper V2 seatpost, Blackspire Brute flat pedals and the flawless Maxxis Assegai/DHR II tire combo
The “budget” kit comes with a Marzocchi Z1 shock and Bomber Coil, a Blackspire bar/stem combo, and SRAM Code R brakes.
The mid-range build jumps to We Are One Composites Union carbon wheels, a RockShox ZEB Ulitmate fork, and a Super Deluxe Coil shock.
On the higher end, the Maxed Out kit features an EXT Era 170mm fork and E-Storia coilover, We Are One Composite Da package (tyre/stem) and Union wheels, this time with Industry Nine Hydra hubs. Stopping is handled by Code RSCs.
A frame option will retail for $5,750 that includes an Effigear shifter, SRAM shifter and RockShox Super Deluxe Coil.
Driving impressions
A day is hardly enough to learn a bike, although I quickly became confident in the AC1’s ability to descend – this tall articulated platform had no trouble eating up the old steps of the North Shore with its rear axle road.
There’s less drivetrain noise because the chain is properly damped between the stays and there’s no ratcheting effect from the derailleur clutch that messes up compliance over small bumps. If you’ve ever ridden a traditional chainless motorcycle, then you’re familiar with that sliding sensation. It brought back memories of the last time I rode a bicycle with a gearboxalthough the belt takes that silence to another level.
Most high-rev bikes are notorious for being slow at lower speeds due to their increasing chain length. The AC1s short 435mm chain and 27.5” rear wheel seem to spin quickly in corners. The bike never felt nervous or wanted to understeer, but with more time I would experiment with a stiffer spring than the 400# we tried.
Alex prefaced this and observantly picked up on my feedback. He mentioned how moving the spring rate would barely change the sag, but would stay further up the progressive curve and weight the front wheel a bit more. This level of progression reminded me of Crestline VHP205RS where the beginning of the trip moved with ease and intensified strongly.
How about the steel chassis? Well, there are elements of steel Cotic RocketMax there too. These little tubes don’t act like a carbon drum machine. Instead, they dull the little circuit or cable noises that do occur.
In terms of flex, the AC1 rode on alloy wheels and didn’t have a disturbing amount of flex in the steel rear triangle, but that would be something to dive deeper into during a long-term review. Most importantly, though, there was no carbon vibration through the rear end of the bike.
Climbing requires new techniques and training for the Effigear gearbox, even compared to Machina’s Pinion. Shifts seemed to be less consistent, and if it wasn’t detected when the pedal stroke was slack, you could stay in gear until it decided to shift at will. Spending more time on this would probably result in less shiftiness, although I certainly appreciated the trigger switch.
Based on the comments left by some of our readers, the steel frame with high hinge and gearbox is the future. I’d be curious to bring a bike like this in for a longer term review against some of the other systems out there – maybe a shootout with a gear bike is in order.
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