Powerfly Trek Powerfly4 speed/mileage off


New Member
Mar 20, 2023
This spring we bought my wife a size small Powerfly4 Gen3. It is completely stock with the Purion controller. As a size small, it's on the 27.5 wheels. I suspect the controller maybe be set for 29 wheels. Is there a way I can check wheel diameter without taking it into the shop? I don't want the odometer reading higher mileage than she's acutally putting on it for warranty reasons and I feel shorted if it's supposed to have assist to 20mph but it starts to cut out at 19mph due to the coding, which is really 16'ish mph.

BAckground - On one of our first rides I noticed that her system recorded mileage was more than my GPS (Lezyne MegaXL) recorded mileage. The Lezyne is pretty accurate/consistent in the routes it tracks but I chalked it up to GPS just not being as accurate as the wheel sensor. A couple weeks ago we were riding and she was having trouble keeping up with me at around 17mph on my computer. Her assist starts to cut out around 19mph on her bike so I didn't understand. She said her bike showed about 19mph. Again I chalked it up to GPS descrepancy. This morning I used her bike to commute to work. I consistently kept it pegged at 19mph on her display and my computer was showing a hair over 16mph. Upon reaching work I did the calculation for moving time and distance and it came out to 16.2mph. So I suspect the tire diameter value is incorrect.

Ride 2d@y

New Member
Jul 12, 2023
Best to take it in to a Trek dealer who can run the Bosch diagnostics and update the software etc. Big Trek dealer like Freewheel in the Cities has the expertise etc.

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