Motorcycle Repair: 79 honda cx 500 custom, honda cx 500, engine transplants


Question
im wondering if i could swap out the cx 500 motor and replace it with an1100 from a goldwing. it looks close just wondering before i get everything torn down. im sure id have to fabricate some mounts but im wondering size wise.

Answer
Hi Ed,

I can't really recommend such a swap as the 500 engine
is used as part of the frame support on these bikes.
The frame and suspension are not made for the weight
of a Goldwing engine.

Other problems you would face are engine mounts, cooling
system radiator too small and different ignition, charging  and
fuel requirements.

The drive gears on a 500 may not handle the added torque of
the Goldwing engine for long.

If you are just experimenting you can fit anything into anything
with some work but this bike would generally be unsafe
due to frame and suspension weakness.

My opinion is the money would be better spent on getting
a used Goldwing or a frame that can handle the weight
rather than shoehorn that engine into a CX500.

I would hate to see that frame or forks collapse at highway speed
with anyone on it, wouldn't you?

I know it sounds like fun but the bike would flex so much it would
be unusable and this flexing from the weight is what creates cracks
in the frame.  I have tried similar projects and so speak from experience.

I had one bike break in half with the forks going one way and the rest the other.
I lived with only a sprained ankle but never mixed bike parts after that.

Some examples of engine transplants:

http://www.bigbikeriders.com/48cyl.htm
http://www.harzer-bike-schmiede.de/Bilder/anfahrt1.jpg

WS
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