Homemade GPS Bike Mount

This little project came about from wanting to clock my speed while out biking. I had been going to buy a bike mount for my Garmin 60csx, but all the reviews I read said that it was prone to popping out. To that end, I engineered (in very little time) an extremely secure way to fasten it to my bike while still being able to remove it for hiking, and which is easily modified by anyone for their own GPS.

Also, sorry if the instructions are not quite up to par, this is only my second instructable, and my first one wasn't very complicated to begin with.

Edit: Please feel free to post any comments on how I might improve this instructable or future instructables, I could really use the advice.

Step 1: Materials

 This bike mount is fairly simplistic, and requires very few materials. Despite this, its extremely strong. To that end, you will need:
-Bungee Cord (short)
-2-3 Zip ties
-GPS Belt Clip (The one that comes with your GPS, though most belt clips of the same kind will do, as they are the same diameter connector)
-GPS
-Length of foam pipe insulation
-And a knife(or scissors)
-A bike (obvious, but not pictured)