I know a little bit about the radios you mention. They used to be only available from Motorola and were very pricey. Now they are made by all kinds of companies and price has come down.

I have a cheapo set that I got at a Target store for $39.00/pair and they are OK for general use with the family at the park or zoo (or bike ride). I found out from my oldest son that I should have paid a little more and gotten the ones with 14 channels and 38 subchannels. That frees you up from interfering with others in the 2 mile radius that may be on the same channel.

On long car trips when there is more than one car it is really handy to have multiple channels. Otherwise the likelihood of getting in on someone elses conversation is very real and annoying. On a bike trip it may not be as big a deal especially since you are so close and not mixing in with hundreds of other people. Of course the extra hands-free accessories will be an additional cost more than likely. I have the Cobra brand and they seem to work fine, although have a supply of batteries since you will burn through them pretty quickly.

Hope this helps.