Theres hundreds of them…..

http://www.motorcycleradar.com/

EDIT….check out the Solo S2…runs on 2AA batteries….I think it may have bluetooth for a wireless headset too….but no wires to the bike if you dont want, although hardwiring a lighter socket is pretty easy.
References :
Honda & Suzuki Service Technician
Graduate of MMI (Motorcycle Mechanics Institute) Phoenix Az.
25+ years riding experience

Another plus for the Valentine one.

Escort makes a good detector for the motorcycle too.

You need to look for some degree of waterproofness.

Also, Laser detection on a motorcycle is limited. Think about how you have to mount the detector - you are in the way of the detector for rear detection and the windscreen is in the way for front detection. Laser is light and the detector has to be in clear line of sight to detect.
References :

As stated there are hundreds of models to choose from but beware.Some States and some Canadian provinces have laws against them.One in particular is Ontario Canada.If you get caught with a radar detecting device installed on a motor vehicle they will seize it remove the device and sell it at public auction.
The vechicle not the device
References :
35yrs lic mech
40+ yrs riding