Cross levers are named as such because they are commonly used in cyclocross races. This addition places two extra brake levers on the top of the handlebars, so that you may brake without placing your hands on the hoods of your dual shift/brake levers or in the drop bars. These brake levers work in conjunction with the ones you already have, making them relatively simple to install and use.
Set your bike on its kickstand or in a bicycle work stand. Locate the brake cable stop bolt on both the front and rear brake calipers. Loosen these bolts with a 5 mm hex spanner. Pull the brake cable out of the housing and let it hang from the existing brake levers.
Attach the right cross lever to the right side of the top of the handlebars. Use a 5 mm hex wrench to tighten the clamp bolt and hold the cross lever in place. Hold the brake cable housing from the existing right brake lever across the top of the bars. Cut the housing with a pair of cable cutters where the housing crosses the cross lever.
Set the end of the piece of housing that runs from the existing brake lever into the housing stop on the right side of the right cross lever. Insert the end of the piece of housing that runs to the rear brake into the housing stop on the left side of the right brake lever. Repeat this procedure to attach the left cross lever to the bars and the front brake housing to the left cross lever.
Insert the rear brake cable into the cable housing of the right brake lever. Slide the cable through the first piece of housing, through the cross lever and into the second piece of housing. Route the cable to the rear brake and secure the cable underneath the rear brake cable stop using a 5 mm (13/64) hex spanner. Repeat this procedure to attach the cable from the left brake lever to the front brake caliper.
Take your bike out for a test ride and squeeze your new cross levers a few times. The bike should stop just as effectively using these levers as with the standard dual shift/brake levers. You can now use either set of levers at any given time to stop or slow the bike.