Ground planes are eminently practical. You have a built-in groundplane
called a bike frame/engine/fenders/wheels that are all electrically
interconnected. Mount a small aluminum bracket with a BNC(f) connector as
high and as close to the mechanical center of the bike that you can (the
handlebars sound like the optimum location) and then into a BNC(m) connector
solder a quarter wave 19" whip made out of brass brazing rod for 2m and
another BNC(m) connector with a 6" long brazing rod whip for 440.

You will be amazed at the performance gain over the rubber duckie lashup you
are using now.

Jim



"Nick" wrote in message
...


groundplanes are not practical. On 70cms
the aerials will be physically smaller but not sure how the range might be
affected / reduced