I had two BMW's, a '02 K1200RS and an '05 K1200GT. I loved those bikes!

I had back pain on longer rides as well when I bought my Street Glide, but when I changed out the bars to some 12.5" apes, the back pain went away. I rented several HD models for days at a time to test ride before making a decision. The worst back pain came from a Road King for some reason (100% stock).

Now I just miss the power and handling, but not the attitude of the riding groups lol....

 

I would try to make some adjustments and give it some additional time to get used to. When I first bought my rocker, I thought I might have made a goof at first, but after doing 3k miles and setting the bike up better for me, I wouldn't let this bike go for nothing, LOVE IT!! I would work on your seating position, seat (my new one was like night and an day over the stock one) and maybe better leg position?? I changed all these and it made a huge positive difference! A motorcycle is like a good horse or woman, you need to ride them for 3000 miles or so to see if it's a good match. Don't give up and ride safe.

 

A bicycle pump will do

 

You're correct that with the BMW your legs were part of the suspension system. On the HD, you really need to make sure all parts of the suspension are working optimally for you. definitely add air to the shocks and make sure your tires are inflated properly.

The BMW also promoted a better riding posture. With the HD, you have to be more diligent in maintaining a proper posture. As has been mentioned, you need to sit up straight and not slouch. A back rest helps prevent the slouching. I have a windshield on my Road King which I look above by about an inch. I can tell I'm starting to slouch when the top of the windshield starts to occlude my line of sight.

Finally, it is difficult to "get up off the seat" on an HD, but when you anticipate hitting a severe bump, try to lean forward and lighten the load on the seat to minimize the shock to your spine.

 

I had the same problem. I put a 4" riser on the triple trees which elevated my bars,which relieved some pressure on my lower back,and I put a mustang seat on which completely fixed the problem.
There are infinite seats and backrest options. I'm sure you will find something.

 

So true. Took me a while to get my RK just right.

That said, if the OP can't get the bike right, go back to BMW for safety's sake.

Riding while distracted/in pain/even in a foul/sad/not sharp state of mind is a good way to get tagged by a texting cager even faster than normal.

 

You might also try moving your handlbars forward or backward in order to adjust your ride position.

Best

Greg

 

I got the shocks up to 28 pounds - Paid the Harley tax & got the pump at the dealer - nice pump - just road down the street and back - I can tell a big difference in the ride - I don't know if this is a cure for me or not but i can tell it will help for sure - i'll also order a back rest today - I think were on the right track - I really want to keep this bike so dumping another couple hundred bucks into it will be worth it if it helps & there is only one way to find out - tom

 

Aleve is the answer .... After some time your back will get used to it and you will have forgotten all about that beemer

 

My backrest made all the difference in the world. It forces you to sit upright and to have good posture instead of hunching over.