Since Brake! Taillight are getting harder to obtain a lot of riders are going the hyperlites route:
Hyperlites for the CS can be obtained here
Ok here is the rundown on the Hyper-Lites installation. I got the F650CS kit with supplied the 2 hyper-lites with 8 LEDs each, the flasher and the license plate bracket.
To start the installation you remove your seat to access the taillight. The instructions say to remove the taillight, but I found this to be unnecessary. To wire the flasher into the circuit you remove the plugs from the taillight, plug in the wires from the flasher and then plug the original wiring into the top of the top flange of the plugs for the flasher. This can be a little difficult as this is fairly tight, but should not take too long.
The ground wire is the middle plug. To determine which plug is the running light and which is the brake lights, remove one plug, turn on the bike and check the light. Once all of the plugs are in place and secured, temporarily wire in the hyperlites, turn on the bike and hit the brakes to make sure the hyperlites are working.
Remove your license plate. Using a drill make a hole in the middle of the plastic backing piece as high as possible to allow the wiring for the hyperlites. Thread the wiring through the hole with the hyperlites on the license side. Thread the wires up under the seat on the left side and using the connectors provided connect the wires to the same colored wires from the flasher unit. Hyperlites supplies the positwist connectors which seem to make a good positive connection. All that is required is to strip about 1/2” of insulator from each wire and then twist them together, feed it through the bottom part of the connector and then twist on the top part.
Turn on bike and hit the brakes to make sure that hyperlites are working.
Install License Plate with supplied Bracket behind it back onto bike. Center the bracket before tightening the screws all the way. To make this fit better, I removed the license plate frame supplied by the dealer which was covering the bottom reflector. Mount the Hyperlites to the bracket flanges using the two sided tape. Because the Ohio plate is small, I mounted the Hyperlites on the inner side of the bracket, making sure that the LEDs projected beyond the bracket.
Mount the flasher to an appropriate surface using the two sided tape. I put this onto the back of the taillight housing. Using a ziptie to attach the wires to the wire for the license plate light so that they are tucked up out of the way. Turn on the bike and hit the brakes to check that everything is working.
Note that the Hyperlites are set to flash continuously while the brake lights are on. If you want to have them flash for 5 seconds and then stay on, there is a loop of wire on the flasher unit that you can cut.
Put your seat back on.
My quick impression of the units is that although they are small, they are very bright and visible. The license plate bracket is easy, although with the double sided tape you can mount the units wherever you can have them facing to the back. The key to any such installation would be running the wires to the underseat location of the flasher.
Total time – about ½ hour, difficulty - mild, some easy electrical wiring, other than that use common sense. Total cost - $60 for the Hyperlite kit, plus the value of my time – ie priceless. Satisfaction level – high.