Most of the moto lower triple clamps I have worked with were press fitted with steer tubes. Those are difficult but not impossible to retrofit with replacement steer tubes. Some are clamped on, and those are easy. In either case, to change to a different diameter steerer, you either have to ream the triple clamps to a different size, or you have to machine a step in the steer tube where the triple clamp fits.
I have only seen motorcycle steer tubes that are smaller than commonly used 1-1/8" or tapered bicycle steer tubes. These can be sleeved over (at the crown race and separately at the headset/stem) rather than replaced, if they're long enough to fit the bicycle frame and stem.
In my casual observation, motocross forks tend to be initially softer, but with much longer and more progressive travel than bicycle suspension forks. So I think you wouldn't have a problem with them being too hard, but perhaps you wouldn't use as much of the suspension travel as normal. Keep in mind that moto guys usually want their forks to sag 25% from just bike and rider weight, which would promote terrible pedal-induced bouncing on a bicycle. On an e-bike, you'll be using more of that first 25% of travel for bumps instead of rebound.
There are lots more different springs available for motorcycle forks than for bicycle forks. If you don't like the spring rate you start with, you can change it.
P.S. - yes, the grip section diameter of MX bikes is the same 22.2mm as that of MTBs.
Last edited by Chalo
on Dec 13, 2017 4:23 am, edited 1 time in total.
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