Though many CB's have a highlighted
channel 9 for use in an emergency (which often is automatically selected if you
lose then recover power), it turns out that neither channel 9 nor channel 1
(typically used by motorcyclists all over the US) is the most likely channel to
get help on in case you need it.
Channel 19 is almost
universally used by truckers. That is the channel to go to if you need help.
In case you are curious,
truckers find great satisfaction in the fact that they typically use channel
19, (and have done so even when a CB only provided 23 channels), because they
know that it has the greatest range on typically tuned antennas today! This is
because if you tune your antenna using an SWR (Standing Wave Ratio) meter, you
tune it so that your CB can use both channels 1 and 40. The result is that
channels near the middle of the band are optimized.
You would do better if you
had a cellular phone on the bike, and better if you had a HAM radio on the bike
(I carry all three.) But Channel 19 on your CB is the most likely place to find
an ear if you only have a CB on the bike. Note that you can expect no more than
1-2 miles from your CB, typically line of sight for your HAM rig (but there are
repeaters located throughout most metropolitan areas and many remote areas as
well), and no telling about your cellular phone.