Choosing a Bike for Converting to Electric

Almost any bike can be converted to electric, its just a matter of how many adjustments you want to make. These guidelines are to assist you identify the important considerations which will make your conversion the most straightforward.

FRAME

Steel, Cromoloy or Aluminium frames are fine, they are strong enough for hub motors up to 1500w in the rear, or mid-mount motors.  Bikes with sturdy forks can be used for front wheel hub motors, particularly with torque bars if higher power (we only do 250w motors for front wheels as standard).  Carbon fibre is not really appropriate for any conversion, as this material is not designed to carry the additional weight and torque of a motor and battery.

BOTTOM BRACKET

To fit a mid-drive motor, you will need a bike with a standard BSA bottom bracket, or a PF30 can be used with an adapter.  If your BB is wider than the standard 68 – 73mm, you will require a special wider motor, for Fat Bikes for example.  Ask us if you have anything non-standard and/or you are unsure.

DROPOUTS

The stronger the dropouts (where the wheel axle sits), the better your bike will handle a hub motor with torque running through the axle.  We include torque bars with all our 1000w & 1500w kits, it is critical they are used.  The axle on the motorised wheel is extra thick, but is trimmed to fit standard dropouts, it is 10mm wide across its flat sides, which will fit in most dropouts (new bikes may require some paint in the dropouts to be filed away).

If you have “Laywer Lips” (a concaved ridge around your dropouts, normally for ‘easy drop-out wheels), you’ll need to make sure the washers fit in snuggly and allow a flat tight surface for you to tighten your nut against.

HANDLEBARS

You will be mounting at the very least an LCD display over the headstem, and the buttons to control this are pretty slimline (can mount under gear shifters usually).  Optional controls to fit are a throttle (thumb style is standard, half twist is also available on request), which can sometimes clash a bit with gear shifters (we often fit thumb throttles on the left, as we have to move shifters towards the middle a bit, and this matters less for shifting on the front derailleur).  The other component is safety cutout brake levers.  If you have integrated gear shifters and brake levers, or hydraulic brakes, we also supply a brake cutout sensor, rather than the lever, to fit to your existing lever.  Mid drive systems also have a gear sensor cutout to feed onto the gear cable.

BATTERY MOUNTING

Ideally, you would want the weight of your battery as low and central as possible, to minimise affecting the balance of the bike, so.. for better handling.  We have a variety of batteries to suit different applications, as follows:

Rack style

If you are mounting a rack battery (usually for step-through style bikes, or cruisers), you will need some holes near the rear dropouts, and also on the seat stays, to bolt the rack legs and arms to.  Mounting here causes the weight to be a bit high, which can affect handling, especially on bikes with a lot of flex.. but sometimes there is just no alternative (not enough space in the triangle of the frame).

Our rack batteries come complete with a rack which is still usable for other things on top, the battery slides in and out (and locks in of course).  We also offer a handy bag with fold-out panniers which can be mounted on top of the rack, making the battery more subtle, while giving you great luggage space.

Frame Mounting

Great for keeping the weight more central, better balance and weight distribution.
For our frame-mounting batteries, its easiest if you have lugs on the frame which are designed for the water bottle holder, the bracket can usually screw straight into those.  Sometimes to get the correct positioning, you will need to drill an extra hole into the frame (we use Rivnuts).. Most bike shops could do this for a small fee.

If you require longer-range or specially shaped batteries, contact Melbourne Custom Batteries for a quote.

For front wheel conversions:

FORKS

We only fit 250w motors in front forks, all other more powerful motors are designed for rear wheel mounting (with the exception of tricycles).  Carbon forks will not generally be strong enough for any twisting force, we will not guarantee they won’t fail.  Most other forks will be fine for 250w.  Suspension forks will be fine, so long as they are decent quality and in good condition. The standard dropout width of 110mm is the width allowed on the motorised wheel axle.  Be aware you will not have a quick-release on the motorised wheel, you will need to undo nuts to remove the wheel (if that bothers you on the front, fit a rear wheel motor).

For rear wheel conversions:

It’s generally fine to add a rear wheel motor to any bike, although the conversion is a bit more complicated, having to play with the gears.  Our motors have SPLINE mounts now, to suit cassettes from modern bikes, rather than the old style of screw-on freewheels.  If you don’t have the tools to get your cassette off the existing wheel, a local bike shop will help you, or we can supply a matched one fitted to your motor for about $50.

Disc Brakes:

Our hub motors are all compatible with disc brakes.  The included electric cutout brake levers are only compatible with CABLE brakes, not hydraulic disc brakes, but we do have BRAKE SENSORS which you can mount to your existing levers instead if required.  You may need a disc spacer to get the disc into the correct position on a hub motor (they do come with one, which you may or may not need to use), ask us about these if you need any extra.

If you have any questions about our kits and how they will mount to your bike, please give us a call, or email a picture of your bike (with name and model) to info@rev-bikes.com