GSM Motor Gear Change Sensor

awol

Esteemed Pedelecer
Sep 4, 2013
1,216
374
My first test rides with a GSM crank motor and have found it very different to my usual hub driven bikes to use.
Me and the motor did not get on with changing gears with the motor under load which it generally always was, I could not get to blip the brakes and change gear in time so always ended up with a clunk.
Since I'm using a KT controller I cannot just plug in a BBS gear sensor.
But I come up with a solution using a BBS gear sensor and I don't want to cut the cable on the expensive gear sensor either.
So cut the socket off a cheaper BBS brake wire 'Y' adaptor and solder on an old HWBS wire 3 core cable with a jst plug on the end,
IMAG0183.jpg
Connection is red to red, black to black, then the other colour is signal to signal.

Connecting this to the KT controller brake sensor circuit really has transformed the bike for me and has been a well worthy project.

Obviously when going really slow under load you still get the clunk because the grears haven't had time to change before the power returns.
 
Last edited:
  • Like
Reactions: Woosh and Nealh

Nealh

Esteemed Pedelecer
Aug 7, 2014
20,981
8,565
61
West Sx RH
Nice solution awol.
 

anotherkiwi

Esteemed Pedelecer
Jan 26, 2015
7,845
5,786
The European Union
If it clunks you're doing something wrong :rolleyes:

On a road bike it doesn't so I guess you are riding off road? I am using a 7 speed Acera derailleur at the moment with an 11-32 cassette (a 12-32 actually but I swapped the small gear).
 

Woosh

Trade Member
May 19, 2012
20,451
16,916
Southend on Sea
wooshbikes.co.uk
Last edited:

awol

Esteemed Pedelecer
Sep 4, 2013
1,216
374
On a road bike it doesn't so I guess you are riding off road?
Yes, it's going to be more for off road use.
I never knew there was one already available from Woosh, guess I will ask first in future.
 

anotherkiwi

Esteemed Pedelecer
Jan 26, 2015
7,845
5,786
The European Union
In other threads I got cheeky remarks about my superior shifting technique but I have only been using click shifters for about 3 and a half years! Shifting on the trike without a motor goes clunk and I have that down to the quality of the rear derailleur and/or the precision of the shifter. There is an awful lot of cable between the shifter and the rear derailleur too. We shall see what adding a motor to the drive-train brings.