Re: What type of engine do I need for a Trek 4500
That Trek 4500 should fit most any engine kit. A frame mounted 2 or 4 stroke kit will fit with a fat (frame) tube front mount or muffler clamp. You should be able to use a rack mounted engine also. Most any electric should fit.
If you have disk brakes, there are vendors that make sprockets and sprocket adapters that take all of the wobble out of the back wheel.
Check out the photo gallery to see what appeals to you.
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