I had the same problem with my 2012 Iron 883. I tightened up the springs 2 notches by buying an adjustment tool from HD, $11. The bottoming out stopped on my rear shocks, the front does bottoms out now once and a while. The rears almost never bottom out now. The ride seems firmer than what it was but I see that as an improvement.

 

Just put SG 12" shocks on mn N a few weeks ago. Night n day difference. Install was simple. Hit the hardware store and pick up eight 12mm washers. Place two on each bolt and everything will line up. You can use the original bolts. Dont forget the blue loc-tite. Rode em a couple weeks with 0 air, then bumped em to 6lbs. Perfect for the way I ride.

 

I weigh about 150 and if there HD that would explain it. I couldn't find a number except on the spring. I might have ordered the HD because the stock ones were bottoming out, but I don't remember.

 

Changing the stock shocks is something many of us do, but my advice is never buy them in a box off the shelf. Get them from a dealer who will ensure they are suitable for your bike and YOU. Sending shocks away to get the springs changed is plain daft - get the right ones fitted from the start!

 

Legend Air Suspensions are awesome on sportsters...They utilize the full wheel travel allowed by the bikes frame and swing arm, air up for added load, air down for us shorter folks to touch with ease, and give a smoother ride too. There's a short lady on a bagger on their website videos that explains it all well.