heres what alot of guys use around here for a computer,watchdog 2000http://www.dugasengineering.com/,you can mount it directly to your top clamp,but I have another great product to mount your computer,watch,roll chart and your damper mounts under your bars,neat setup,cleans up everything as well
www.ptenduro.com heres a picture of this setup on my 300( havent mounted my damper quite yet)
