has anyone ever used the suction cup on there gps on the tach . leaving on trip to wash dc. on short notice don't have time to buy a ram mount .

 

I used to use it on a Nuvi 500 and stuck it to the lower left windshield. Tied a black shoe lace to the clutch cable and mount for peice of mind to prevent it from bouncing down the road. It never fell off, although it vibrated right much at idle. Love my Zumo!

 

Ive used it twice now for short hr or hour and a half rides over some pretty bumpy Michigan roads and never had any issues on either trip.

 

If you like your GPS I wouldn't chance it. They fall off on the windshields of cars. Can't imagine on a bike.