Debating switching out the Ohlins I have on my 03 RKC for my 15 RG. Will the harley hand adjustable fit without issue? These would be the 12" shock.

 

they'll fit just fine. but, they are not recommended. your bike runs the older, less substantial swing arm. because the shocks only have adjustment on one side (left), the theory is that one side will not stay with the other and your swingarm will have some flex, which could lead to wobble.

though there are certainly instances where folks have done it and not had any issues....

 

Try them and see, I don't have any issues.