To answer you better, a little more information about the mission would be needed. Bike-to-Bike comms can mean a few different things.
My wife rides her own bike so we have had several different comm systems. None of them are Citizens Band (CB) or the British equivalent. First we had the Cardo Scala Rider Q2 systems which worked well. We next had the Nolan helmet integrated systems which had good range and battery life but suffered from a poor interface. Now we have the Sena SMH-10 system which is built into our Bell helmets. The Sena system is fantastic. About a mile range and very easy to use interface. Highly recommended.
If you are looking to replace the Kenwood, then the Sena unit is the way to go. Now if you use the Kenwood as a long distance communicator or to general public comm radios (PMR 446?), then you can also plug the Kenwood into the Sena. It just depends on what your mission is.
I hope that helps.