Ok so here is the deal I took my longest ride 2800 miles, 2 days riding, 2 days at the destination then 2 days back. I had some pain for sure. Lower back and some in the upper back. I riding a stock '11 FXDWG I weigh 170lbs. I am going to upgrade the seat to a mustange vintage solo. I wanted to upgrade the shocks too because in July I will be going to Charleston. I ride solo, but on longer trips I have 20-30 lbs of gear. The question I have is which shocks will work for me?

I am trying to save a little coin here. I had convinced myself that the progressive 430 or 440 was the way to go but I was told that the 412 is all I need.

Also I'm all about the ride quality. I don't want to lower the bike at all. So I'm not sure on which length shocks to get. I wouldn't even mind a slightly taller shock for increased ride quality. Is going with a slightly longer shock worth it?

 

I put 50k on the 412 and they still hold up. IMHO that's all you need for a light bike like the FXDWG.

 

The stock shocks are sprung quite well for your weight. Since your upper and lower back get fatigue, I would say your issue is with your riding position, not your suspension. Sounds to me like your back isn't straight. A slight curve can cause your malady. A supportive seat with a rider backrest would be my recommendation. Go ride a bike with back support to see the difference that'll make.

 

I can see that for sure. The most comfortable position for me is not actually in the saddle its on the seam of the seat and passenger pillion. I'm ordering the Mustang Vintage Solo seat which should raise me up a little.