A new e-bike isn’t the only option for assisted pedalling. You can save money by converting a bike you already own – especially if you use Cyclescheme.

An e-bike conversion kit adds a motor, battery, sensor and controls to a conventional bike. It can be a cheaper route into e-biking because you’re only buying the electronic parts, not the bike itself. And your existing bike may well be better quality than budget e-bike.

The government advises caution about e-bike kits. It says: “buying a complete e-cycle is generally a safer option”. This isn’t an issue with conversion kits as such. It’s more a tacit acknowledgment of the many cheaply converted e-bikes that don’t meet UK safety and legal requirements.

Ever been passed by a food delivery rider doing 25mph without pedalling, on a bike with a big battery held on by cable ties or gaffer tape? That’s not an e-bike under UK law. It’s a motorbike. It may also be unsafe. E-bike fires are generally caused by cheap or incompatible batteries and chargers that have been bought from online marketplaces.

E-bike conversion kits can, however, be just as safe and reliable as complete e-bikes. The five below are sold by reputable sellers that are recognised brands in the cycling world. They comply with UK e-cycle regulations. The manufacturers or their dealers will work with you to confirm that your bike is suitable for the conversion. They’ll even do the conversion for you; some don’t allow DIY fitting at all.

The prices shown are minimum RRPs for the cheapest version of the whole kit. Note that you can make the usual savings by using Cyclescheme.

ARCC £1,899

ARCC’s Intelligent Drive System is designed and made in the UK, which along with the high quality accounts for the cost. It comprises a front hub motor, a Bosch powertool battery mounted on the head tube, a bottom bracket torque and cadence sensor, and a Bluetooth controller. One neat feature, called Launch Control, gives a three-second power boost when setting off from a standstill to make hill starts or traffic light accelerations easier. The whole system adds only 3.9kg to the weight of the bike. ARCC specialises in converting small-wheeled bikes such as Bromptons, Moultons and Airnimals – and in fact also sells brand new converted models – but can fit the kit to almost any bike. ARCC does the conversions; you can’t fit the kit yourself. ARCC picks up your bike and ships it back to you, which is included in the price for standard conversions. ARCC’s battery sizes range from 144Wh to 324Wh, but the small size means that a spare for longer rides is easy to carry. The ARCC system comes with a five-year warranty (three years for the Bosch battery).

Cytronex £955.64

The first Cytronex kit was produced back in 2008 and pioneered the ‘stealth e-bike’ concept: an e-bike that looked like a conventional bike and didn’t weigh a whole lot more. Designed and built in the UK, the kit adds from 3.2kg to 3.6kg to the weight of the bike. Its 198Wh battery is styled like a large water bottle and fits where a water bottle would. The first Cytronex kit used a front hub motor – and most still do. The company has recently launched a slightly more expensive rear hub motor (142mm thru-axle only). This will provide better traction on steep hills. You can buy and fit the kit yourself; the cheapest option (price shown) is to build the hub motor into a wheel but it’s not much dearer to buy it as a complete wheel. Cytronex will convert your bike for an extra £155. The Cytronex kit is intuitive to use, with one-button operation, optional bike light integration and a mini charger that’s small enough to fit in a seatpack for mid-ride charging. Note that Cytronex is not currently listed as a Cyclescheme retailer.

Nano £865

The Nano conversion kit was originally designed for Brompton folding bikes but is now also offered for other small-wheelers, such as Moultons (pictured) and Terns. It consists of a front hub motor built into a wheel, a pedal sensor, a controller and a battery. The standard battery is a 144Wh powertool battery, like that used by ARCC, but you can order a larger 360Wh battery if you want to do longer rides (e.g. 30 miles) or live in a very hilly area. Either way, the battery is designed to fit in a Brompton front bag. There’s a choice of controller. One is a display with buttons, like those of other e-bikes. You can select the power mode and turn assistance on or off. This the best option if you’ll be riding with assistance most of the time. The other two are throttles: a twistgrip or a button. You only get assistance when you use the throttle, and the more you twist or the harder you press, the more assistance you get. This works best for if you want power primarily for hills and for setting off from stationary. You can fit the kit yourself or Nano will do it for £190 (collect, fit and return). Nano is Cyclescheme registered.

Pendix £1,699.99

The German-made Pendix eDrive is different from the other kits here in that it uses a mid motor rather than a hub motor. This is integrated into the supplied crankset, with the motor sitting on the lefthand side. It will fit pretty much any bike with a 68mm or 73mm BSA bottom bracket, including folding bikes and tandems, adding around 7kg for the whole kit. As with any mid-drive, efficiency is good because the motor gets the benefit of the bike’s gears. Even with smallest (300Wh) battery option, you can expect to go further on each charge than with the other kits here – more than 40 miles in optimum conditions. At 65Nm, the motor’s torque is high, which is better for steep hills and heavy loads. The battery – different capacities are available – is a bottle-style unit that fits to bottle cage mounts on your bike’s frame. Unusually, the controller is on the battery itself rather than separate. You choose modes using a rotary wheel where a bottle’s cap would be. Pendix kits are only fitted by Pendix dealers. You can find your nearest on the website of the UK distributor, Velobrands. Many of the dealers are Cyclescheme registered.

Swytch £499

Of the better quality (and legal!) conversion kits out there, those from Swytch are among the least expensive. They start at just £499. That gets you the Swytch Go, which has a frame-mounted 180Wh battery, a front hub motor built into a wheel (26in/ISO 559 or 700C/ISO 622), a pedal sensor and a display/controller. The Swytch Go+ and Go++ are the same but with higher capacity batteries. The Swytch Max, which starts at £599, is a little more sophisticated. It mounts the battery in a quick-release handlebar clamp. The larger capacity Max+ and Max++ batteries light up and thus function as front lights for being seen. They also have a USB-C port that you can use to charge your phone. Most Swytch kits use a front hub motor but a rear hub motor is an option with the Max+ and Max++ kits. All the kits are light, adding from 2.6kg to 3.7kg to the bike. The Swytch kit is easy to fit for competent home mechanics. However, Swytch has dealers around the country who will sell and fit the kit. Some of them are Cyclescheme registered, so using them rather than buying direct from Swytch may be cheaper as well as easier.