I'm thinking of adding a bump switch to the start here robot
https://www.robotshop.com/letsmakerobots/start.
I'm thinking of adding a bump switch to the robot, do I need any drivers? or anything?
http://rocketbrandstudios.com/
help is at hand…sort of
You’d want to connect on terminal of the bump switch to +5V and the other terminal to an input on the picaxe. I’ve never used a picaxe so I can’t help you with the code. 
Hey Sunny
The bump switch kit I carry specifically fits the Tadpole robots. That said, it is just a basic, flat plate and the two switches themselves. With a little ingenuity and/or hot glue, I am sure you could get it to stick on to your standard SHR. The kit comes with jumpers etc. which should plug into your Picaxe just fine. As I recall, the Picaxe uses internal pull-down resistors (do a google on this) which will be needed to make the bump switches work properly.
Then again, you grab one of those Tadpole kits and it will just bolt right on, no worries…
Kit and DIY
might go both, kit at the beggining and super glue later for the learning.
I watched one of your vids that asked “do you like to make a robot or want to have a robot”.
So my response is, I hope your kits come as dissassembled as much as possible because I’m here to build.