Hello,

How can I tighten up the back of my bike? I feel like it springs a little to much.

 

You can adjust the pre-load on the shocks. This can either stiffen the suspension or soften it. You will need to lift the bike and use a spanner wrench. Here is a website that will tell you how to do it.
http://www.fatbillscustoms.com/

 

My local HD mechanic suggested not messing with the factory settings. He has had another guy who had tightened up the rear suspension and ended up with a ding in the rear fender due to the fender and tire gap being too close from the adjustments.

 

That is weird...because mine has stops that it will bottom out on before ever making contact with the fender.

 

That is strange, if its tightened up wich is what i am going to do that should make is stiff as ?

 

stiff as...what?
Using the spanner wrench, you will want to turn it counterclockwise to tighten the spring. That will "stiffen" the ride. Turning is clockwise will "soften" the ride.