I am going to install the 4" bar extenders from Phil and I wanted to start a thread with information and suggestions from members that have installed these. Information such as brake/clutch lines and photographs would be helpful. I will update the thread when I start my install. Thanks for any contributions to the thread.
A bit more than two years ago I installed Phil's handlebar extenders to my '09 C-14. I had previously installed two-inch risers that I decided to continue using. The risers alone allowed me to retain the stock wiring and throttle cables as well as the brake and clutch lines. However, the addition of Phil's extenders necessitated longer clutch and brake lines. The stock wiring was long enough to reach and the stock throttle cables were barely able to reach provided they were re-routed to the rear of the fork stanchion.
I did not replace the throttle cables when I installed the extenders because doing so involves removing nearly as many parts as it does to get to the valve covers when doing a valve adjustment. Since I was still some 5,000 miles short of doing the first valve adjustment I decided to forego longer cables until I had the bike apart for the valve work and could afford the down time to allow for the week plus shipping time it took to get the throttle cables lengthened. I rode the bike with no problems until I did the valve work and then I replaced the throttle cables with a pair that were 4-inches longer than stock and was able to route them in their standard locations. One cannot simply purchase longer throttle cables as the fittings on the stock cables are made specifically for this bike and no one has access to fittings that match. The only solution is to send your stock cables to a business that is able to remove those fittings and to use them on new and longer cables. I employed Motion Pro as they do excellent work and as a bonus their price was also the lowest of those I queried.
I replaced both the brake and clutch lines with standard (not braided) Galfer units. The clutch hose installation is pretty straightforward, just follow the route of the stock item. I can only direct you with replacement of the brake hose if your bike is equipped with ABS as mine is. Without ABS I can only presume that you duplicate the route taken by the stock line. However, with ABS there is a short hose from the brake master cylinder to the ABS attachment connecting it to a steel line to the ABS unit. The hose going from the steel line from the ABS unit then connects to the hose going to the junction connecting it to the two hoses to the calipers. As for the advice to upgrade to stainless braided lines, that is good advice from an appearance point of view. All brands of braided lines are quality hydraulic hoses encased in the stainless braided covers that offer an excellent service life. However, the unbraided Galfer hoses I used offer the same quality as the far more expensive braided items. The stock Kawasaki hoses are also of that same quality and from a function standpoint there is really no need to replace them other than cosmetic or to change their length. Therefore I chose to change just the line from the brake master cylinder to the ABS attachment connecting it to a steel line to the ABS unit. I left the other hoses in place as they contain hardware fittings not present on the replacement items. Replacing these lower lines will prove to be a hassle requiring a bit of fabrication. My hydraulic hoses and my throttle cables were all extended 4-inches.
Bear in mind that I am also using two inch risers that require a slightly longer reach for all of the replacement items. My extenders from Phil are 4-inches also. In addition to the handlebar expenders Phil also included the two hose clamps that attach to the top triple clamp. The smaller of the two pictures below show them in a photo of Jay Wilcox's (ZG) bike that I copied from one of his posts. I couldn't use the one from Phil on the brake side as it brought the hose too far to the inside so I just made one of the appropriate size that placed the hose in the proper place and also changed its angle for a perfect fit. You can see it in the larger photo below.
I hope this helps you in your quest for greater comfort. I must say that the addition of the extenders from Phil did a great job of allowing me to ride in comfort. They look peculiar as hell but are an example of his exemplary craftsmanship. They don't affect the quality of the bike's handling but certainly do have a positive effect on the rider's level of comfort. They surely have my enthusiastic endorsement.