Help! Help building my first ebike


Finding my (electric) wheels
Feb 11, 2019
Hello all, this is the first ebike i'm building and need some advice (this bike is meant for off road purposes).
First i'll tell you the parts I have/have bought and are on the way.

Donor bike: Is a Giant Talon 3 2018 in good condition
Motor kit: Rear hub 1500W 48V motor
Battery: 52V 20Ah

So I have a few questions, mainly about the brakes.

The donor bike I have has Hydraulic disc brakes. In the kit it comes with new brake leavers for motor cut out (but only for cable brakes). Therefore, I've seen you can get a magnet sensor you put on the brake leaver that works in the same way. Would it matter which one I get? Are they all compatible with the controllers? Also can anyone link me where I can get one in the UK?

I was also wondering about how I remove the disc brake from my current bike to put on the new motor wheel. Is it simple or do I need specialist tools?

Also do you think this is a good setup in general for just having some fun, nothing too serious?

Thank you for any help

Laser Man

Jul 1, 2018
Michelmersh SO51
There are two sorts of magnetic brake sensors for hydraulic brakes - 2 wire and 3 wire : make sure that you get the correct type for your controller. (The 3 wire (3 pin) ones are generally sold to go with the Bafang mid drive motors).

There are also two types of disk rotor fittings. If your bike has 6 screws holding the rotor on then compare the lengths of the screws between the original bike ones and the ones on the motor - if the motor ones are shorter, then these are the ones to use. If the motor ones have round heads (as opposed to triangular) then you can't use the anti-rotation tab washers so use some threadlock instead.
If your existing rotor doesn't have the 6 screw fitting, then you will need a new rotor too.


Esteemed Pedelecer
Feb 28, 2016
Hydraulic brake sensors are available on ebay fron £5-15 depending where they are sent from. You only really need 1 on the rear brake, although some like to fit on both. Most are 2 pin and will work on any controller, but you may need to change/remove connectors. Brake disc bolts are either allen key or torq head, so you will need to check this. You may find if you are running 160mm disc that your caliper will not fit against the motor, in which case you will need to upgrade to 180mm to give you the clearance. good luck with your build and let us know how you get on. Large direct drive hubs work best at higher speed, so are not the best at slow, technical trails, but i'm sure it will put a smile on yer face:D