I have searched through several threads, but have not been convinced yet to purchase a trailtech speedometer. I have a gps system already mounted and hardwired to my Trick Dual Sport kit on my 98 wr 400. I have removed the stock odometer set up and am considering putting a trailtech system on. I have noticed that some dual sporters in this forum have both a gps and a trailtech speedometer. My question is simple. Since I have a gps already, do I need a trailtech speedometer? What can it give me that the gps cannot? Thanks for any replies.