fixerupper
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- Crete Greece
View attachment 152422
I have just fitted a 250/500 watt rear hub motor complete with a 36 volt 11amp hour battery , PAS sensor, SW900 LCD and thumb throttle to my Specialized Rockhopper MTB …the bike works fine on the thumb throttle and it's great to buzz about and now I laugh at hills... but the PAS system seems to have a problem.
The motor starts but cuts out as speed increases, making smooth travel very difficult. In PAS 1 eco level the power comes on at about 7 kph and stops at 9 kph. In PAS 2 std level the power will continue up to about 11 kph and then fade out … and so on up through the PAS levels. In PAS 5 power the speed will get up to about 15 kph. This effect is altered slightly with gear changes. It is impossible to reach the designated speed for this motor, which I think is about 22 kph or 15mph using the bike in PAS mode ,though all goes smoothly just using the thumb throttle. Any clues on how to stop this happening in PAS mode?
Another question. The motor is 250/500 watts dual wattage. Any one know a way you can shift the settings so you know that you are legal (250w only) for road travel? Also the handle bar mounted SW900 LCD shows the wattage varying widely from as little as 75w to 800+ - how is that possible if it is only a 500w motor?
I mounted the PAS sensor on the chain-ring side of the bottom bracket because there was’t enough space between the frame and the crank. The gap between the magnets and the sensor is about 2 mm. Is the fact that the magnets are against the granny cog affecting the magnetic field that the sensor reads? Click on thumb nail for full image ....
The motor starts but cuts out as speed increases, making smooth travel very difficult. In PAS 1 eco level the power comes on at about 7 kph and stops at 9 kph. In PAS 2 std level the power will continue up to about 11 kph and then fade out … and so on up through the PAS levels. In PAS 5 power the speed will get up to about 15 kph. This effect is altered slightly with gear changes. It is impossible to reach the designated speed for this motor, which I think is about 22 kph or 15mph using the bike in PAS mode ,though all goes smoothly just using the thumb throttle. Any clues on how to stop this happening in PAS mode?
Another question. The motor is 250/500 watts dual wattage. Any one know a way you can shift the settings so you know that you are legal (250w only) for road travel? Also the handle bar mounted SW900 LCD shows the wattage varying widely from as little as 75w to 800+ - how is that possible if it is only a 500w motor?
I mounted the PAS sensor on the chain-ring side of the bottom bracket because there was’t enough space between the frame and the crank. The gap between the magnets and the sensor is about 2 mm. Is the fact that the magnets are against the granny cog affecting the magnetic field that the sensor reads? Click on thumb nail for full image ....