Depends on the height of the Bars you want? Style? Make?
Before I replace my second bars (Tall Boy) I had sat on a few different bikes during Gettysburg Bike week, so I had a idea and style, but most important height the bars I want....Yaffee 10' was the call and never looked back...only had to changed my clutch cable out....Good luck

 

This question is one of the regulars which pops up often! Some bar brands will answer your question for you, or offer the extra parts needed for the installation, such as wire extensions and longer cables, etc. Alternatively select your preferred bars, install them, then measure up what you need to give the finished result you will be happy with. There are too many options, on bar shape and geometry, to give an absolute answer IMHO.

 

I have the Wild 1's Beach bars on my RKC, needed wire extensions but not for the brake/clutch lines. I've done several bar swap jobs, 10-12" apes on all touring bikes, and I've concluded that my rule of thumb is anything more than 12" you will need to change the brake/clutch lines and wire extensions. I tell my customers to go with the longest on the wire extensions (15") so that that portion of the job is already done if they want to go taller.

The beach bars on the RK look bad ***! You'll like them!

Ride safe!!