How it works:

​

The ARCC pod system is made up of a very small and neat looking 250W geared front hub motor and a solid looking aluminium ‘pod’ (wiring nexus and battery mount) clamped securely on to the head tube which communicates wirelessly with the handlebar-mounted Bluetooth controller (or an iPhone with appropriate app if preferred). Also feeding into the pod are the cables from a bottom bracket torque sensor and brake lever sensors. 

​

Battery power is supplied by a choice of 144 or 216Wh Bosch power tool batteries and there is the option of buying an even larger 324Wh Bosch power tool battery though that is not directly available from ARCC, despite this it’s easily available through DIY outlets and the like. All three capacity batteries can either be slid onto the pod or used inside an adapted Brompton bag. 

​

Using power tool batteries has the advantages that they are relatively widely available, reasonably priced and likely to be around for a good long time to come. Another plus is that they should be pretty robust if designed for power tool use, indeed they are rated to withstand a 3m drop. The obvious downside is that they are small capacity compared to the modern standard of 500Wh batteries (or bigger) that comes with many current mid-drives. 

 

This might all sound fairly conventional for a retrofit system, but it’s not. The high-tech approach doesn’t stop at Bluetooth control of power levels. The eponymous pod contains control electronics that integrate a 3-axis accelerometer to estimate how steep any gradient you are riding is, automatically adjusting power accordingly if you are in automatic mode. There is also a manual mode and you can switch between modes using the sleek looking wireless handlebar control unit that is smaller than a matchbox. The unit also lets you dial up and down the six power levels, and it removes from its secure magnetic cradle-style holder so you can easily slip it into a pocket as a way of making the bike less attractive to thieves.

​

The ‘launch control’ feature is activated by applying both brakes and pressure to the left pedal – ARCC say the pod senses this and delivers maximum power to the motor for a period of three seconds, so that ‘an effortless get-away can be achieved for safety, when moving away from traffic lights and crossings in heavy traffic.’ The pod also houses a bank of three USBC ports on the side for phone or GPS charging. All in all, the pod is one of the cleverest box of tricks on any e-bike I’ve come across. 
 

"The precision engineering" 
 

What stands out before you have even ridden the bike is the precision engineering. The pod, battery latch, pod side lever, Bluetooth handlebar-mounted controller and cradle components are all CNC-machined from solid billets of 5083 grade Alplan aluminium alloy then polished, hard anodised and weather-sealed. The Bluetooth controller is held in its handlebar mounted cradle magnetically, the cradle being designed with a lip that makes it almost impossible to knock it out accidentally. 

​

There’s further reassurance of the system’s quality in the form of a five year guarantee, and this is complemented by the fact ARCC will honour the Brompton warranty if they supply a new model with the ARCC system (or they will retrofit it to your own Brompton and honour any remaining warranty on that too). Bosch batteries come with a two year guarantee from Bosch themselves. 

​

If you like the sound of system but not on a Brompton, then note ARCC also offer it on Abington, Airnimal Joey, Moulton TSR and Rosemont bikes. ARCC also say they offer bespoke fittings, with previous bike conversions including a recumbent and the PF Mobility Side-By-Side Trike. Unlike most other retrofit systems there is no self-fit option, and the ARCC system must be fitted in-house at their Cambridge HQ.

​

How it feels to ride:

​

The motor pulls along nicely some fractions of a second after you start pedalling, and cuts off almost instantaneously when you stop pedalling. It feels nice and responsive and the effect of torque sensing is clearly in a different league to cadence/crank motion-sensing e-bikes; however, it’s not quite as immediately responsive to pedal pressure as a Bosch or Shimano mid-motor, nor does it have their raw power. The ARCC system seems designed to respond to a reasonably light pedal pressure and early selection of low-ish gears for the most effective hill climbing.  However, once you get the feel for the system it zips up hills in a very impressive manner for such a bijou motor. It’s a little more noisy than average and so will draw a bit more attention to the fact it’s an electric bike, which you may or may not be bothered about.    

​

The Bluetooth control on the handlebars worked faultlessly, never cutting out or turning itself off or any of the other things wireless gizmos can sometimes do. My only real criticisms were the fairly small and fiddly buttons (making it somewhat tricky to operate with gloves on or in the dark), and the fact battery capacity is shown by changing colour of a capacity indicator light, which means it’s hard to get a very accurate indication of the state of charge.  Despite that it’s ideal technology for a folding bike like the Brompton, removing the need for a trailing wire that could get damaged or tangled in the folding process, and it sheds a little weight to boot. There is an alternative to using the handlebar-mounted Bluetooth controller in the form of a smartphone app, but as this is only available for iPhones I was unable to test it on my Android smartphone.

​

Power modes: Automatic and Manual