My Probike now a donor for MTB (eMTB)

AlanRHB

Pedelecer
Aug 21, 2019
27
9
77
I recently bought a cheap, older, mountain bike requiring work on brakes, gears and front suspension.
So after carrying out repairs which only cost me a new chain and front disc brake pads, plus strip,clean and lubrication of front forks and front and rear derailleur assemblies then resetting. I gave it a ride around and realised just how heavy, and due to the length, unwieldy the Dutch style Probike is. Plus due to rigid forks, the discomfort and pain to my arthritic wrists and shoulders riding our potholed roads.

So after ordering a couple of weeks ago, a KT sine wave controller and KT LCD3 display unit from PSWpower (thanks to advice from vfr400 and Nealh,) I decided to convert my new (old) MTB into an e-gravel bike using the Probike as a donor, mainly the rear wheel/hub ass., the wiring, controller and all handlebar controls, and keeping the 24v sealed lead acid batteries temporarily for checking and testing, as for my Birthday on March 1st, Pam has ordered a nice new Li- on 36v 15ah battery from a company in UK. ... :) :) :)

After completion of the transfer, I dropped the lead acid batteries into saddlebags I fitted to the rear rack from the Probike, (I also transferred the (mudguards) in order to road test.
Very pleasantly impressed with the handling and comfort compared to the Probike, even though very heavy SLA batteries either side of the rear wheel.


0331C5E1-D0BA-4757-A646-2DB2806C52B0.jpeg

So far, the new pedal assist sensor I fitted to the right hand crank to replace the Probike one fitted to its single crank sprocket, refuses to work, but the throttle does work very well.
In fact it is quite sensitive, immediate response and will introduce power slowly and smoothly allowing me to creep away from start which I have problems with using pedal power only, particularly on a hill.
I can also feed and hold levels of power at any percentage to assist rather than replace my pedalling using the throttle, and the motor cuts immediately the throttle closes. No drag from this compact, brushless 250w motor when pedalling on the flat or downhill when the throttle in closed, or when I stop the motor when travelling downhill with a quick light jab of the rear brake lever cut out.
Also there is no drag from the motor when the power cuts upon reaching approx. 15mph.

I realise of course that it is illegal to use with throttle only, so will continue to try to sort the pedelec sensor and wiring. The same coloured three wires are arranged in different positions in the multi plug, so I cut the plugs off controller and sensor loom in order to join the same colour to colour... perhaps that was a mistake as each colour may have a different task in controller and sensor.

I hope the throttle will still be legal to use due to the age of both bikes . Meanwhile my project to convert this budget MTB into a Gravel/Adventure ebike continues.
 

Nealh

Esteemed Pedelecer
Aug 7, 2014
20,138
8,231
60
West Sx RH
With the PAS I wouldn't have cut anything off until asked for advice.
In theory if both connectors do use the same colours then they might be ok.
KT controller pas wire is Brown /5v, Black/ Gnd & Yellow /Signal, is the PAS sensor a KT supplied one or did have a wire sequence order with it ?

Some China wire colours can be random and often Yellow can be used for Gnd .

The PAS in your pic is on the LHS, if this is the new one then it might be handed for the RHS. You can fit them on the side you have decided on but will have to re-orientate the disc or sensor. Also the sensor looks like it should rotated 180 degrees so the wire feeds under the BB.
Easiest way to get PAS working is to remove both parts and having wired the sensor up correctly (look to see if the sensor has a Red led), should blink when the disc is passed by the sensor. If not flip the disc face as the poles passing might be directional.
 
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wheeliepete

Esteemed Pedelecer
Feb 28, 2016
2,047
755
60
Devon
Oooh, I can feel the pain and strain of your panniers carrying those SLA batteries, hope they hold out till your new battery arrives. :D I wouldn't worry about your throttle, AFAIK, the powers to be aren't using carbon dating on ebike, yet.;)Enjoy your new ride.:)