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  1. #1
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    Do all rear geared hub motors need 135mm dropouts?

    Are there any manf. of rear geared hubs for a 130mm rear dropout frame?

  2. #2
    Senior Member
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    Some of the 135mm motors, which is an approximate standard, can fit ok in a 130 with two tweaks...a "by hand" frame stretch of 1 or 2 mm on each side, and by filing the axle shoulders on the motor down by several mm. making sure that the "face" of the axle shoulder is flat so it sits flush against the dropout. I was able to get a 135mm Nine Continent motor into my tadpole trike (which is alloy frame and doesn't like much frame stretch) which only had 130mm available using both of these approaches. Everyone I asked said a "by hand' frame stretch of a few mm in total on an alloy frame was ok. You will want a good flat proof tire if the motor is in there really tight, although it is usually possible to fix a flat without taking the wheel off and leaving it in place - as long as you are able to find the hole. the Bafang BPM hub motor seemed to be around 132mm so it was easier, on a different bike to get in.
    The Ezee motors show around 130 on their engineering diagrams, so they are probably fitting with no filing in a 130mm space, or a 135 with some spacer washers.

    I use the spacer washers from ebikes.ca which fit tightly around the axle, as the hole in them is not round but axle-shaped.

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