The Revos is a delightfully simple and affordable e-bike conversion kit that fits (almost) all bikes

Updated bolt-on e-bike conversion kit from Bristol goes into full-scale production

Revos e-bike conversion kit

The Revoloutionworks Revos is an affordable and very efficient electric bike conversion kit that will fit most bikes, can be fitted at home in around half an hour and weighs so little that you can happily ride without it being powered up.

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We first featured the Revos when it had just been launched on Kickstarter back in May 2018. The e-bike conversion kit has seen some substantial updates since then and is now in full production. It is available direct from Revolutionworks for £495 or £595, depending on the battery pack you opt for.

How does the Revolutionworks Revos e-bike conversion kit work?

Revos electric bike conversion kit
The kit only comprises three main components: the drive unit, pedal-assist sensor and battery.
Jack Luke / Immediate Media

The beauty of the Revos is that it consists of only three main components: the drive unit, pedal-assist sensor and the battery.

Its design also means that it can be fitted to most bikes within minutes using just a couple of tools and a few cable ties.

There’s also no controller at the handlebar to worry about, and switching assistance on and off requires nothing more than a slight backpedal at the crank.

Unlike most motor conversion kits, which place a motor at a hub, the Revos — which is assembled in Revolutionworks’ HQ in Bristol — uses a driven roller that wedges between a frame seatstay and rear wheel.

Revos e-bike conversion kit sensor
The sensor essentially ‘counts’ the teeth on the cassette.
Jack Luke / Immediate Media

A magnetic sensor, which is affixed to the chainstay, essentially ‘counts’ the teeth on the cassette — if you stop pedalling, the system will disengage.

The updated control unit then determines exactly when and how much power will be delivered from its bottle cage-mounted 100 or 209Wh battery pack.

This powers the roller, which turns directly against the bike’s rear tyre and provides pedal assistance right up to the UK’s limit of 15.5mph / 25km/h.

The internals of the roller unit have also been updated, losing the planetary gears of the first model and switching to a custom-specified direct-drive system. This is claimed to have drastically reduced the noise and drag of the system, and also increased efficiency.

On that note, Revos claims the system draws just 4 to 8Wh/km. A typical e-bike drive system has a claimed power draw of between 10 and 20Wh/km.

Riding around the most vertiginous locales in Bristol, the Revos team claims it has a typical real-world power draw of around 4.5Wh/km. This is key to making the most of its, relatively speaking, low battery capacity.

The system is also particularly light — just 2.1kg for the 100Wh battery pack option, or 2.7kg for the larger 209Wh option.

Once converted, your bike will be good for around 20 to 40km of riding, depending on the size of the battery pack you choose.

That’s hardly a class-leading range, but Revos is confident that, with the UK’s average cycle trip lasting a little over three miles, it’s a range that will suffice for most of its customers.

Should you end up with a flat battery then the Li-ion cell will be able to be charged to 80 per cent in just one hour, and will be fully charged within two hours. But if you can’t reach a charging point the roller of the drive unit can be manually retracted with a hex key to remove any drag from the bike’s drivetrain. The new battery also has a USB port for charging phones etc.

Both the 100Wh and 209Wh battery packs attach to a frame bottle cage mount.
Both the 100Wh and 209Wh battery packs attach to a frame bottle cage mount.
Oli Woodman / Immediate Media

What bikes will the Revolutionworks Revo e-bike conversion kit work with?

Revos e-bike conversion kit on tyre
The electric bike conversion kit will work with most bikes.
Jack Luke / Immediate Media

The Revos won’t fit every bike, but will work with most.

To make it work you’ll need room for at least a 50mm x 50mm space between the seat tube and rear wheel of the bike it’s being fitted to. The clamp also has a maximum external seat tube diameter of 35mm.

The roller also works best with a relatively slick tyre, so a knobbly tyre would have to be switched out.

Full guidelines for fitting the system can be found on the Revos website.

Where can I buy the Revolutionworks Revo e-bike conversion kit?

The Revos is the work of father and son duo Mark and Hugo Palmer, who started the project back in 2006 and have since left their careers to devoted all of their time to getting the Revos to mass production.

After a successful Kickstarter crowdfunding campaign, the system has now been brought into full production, with pricing set at £495 for the 100Wh kit and £595 for the 209Wh kit.

The kit can be ordered directly from Revolutionworks, but it is also actively seeking a distributor for the brand.

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This article was last updated on the 12 September 2019