Question: Can you do a video on tips for mixing and matching brake calipers and levers for road applications? For example, can I use Dura Ace 7800 STI levers with Dura Ace 9000 brake calipers? Can I use the reverse? From: Phillip
Answer: Until Shimano changed the design of their brake calipers and their brake levers’ cable pull ratio, every cable actuated road brake lever was compatible with every road brake caliper including cantilever brakes.
Shimano made this change when they went to their SLR-EV brake architecture. Rather than list out what Shimano group generations are made for SLR-EV, and which ones are for the traditional brakes, there is a very easy way to understand which levers work with each type of brake. If the shift cables go under the handlebar tape, the lever is made to work with SLR-EV brakes. If the shift cable is exposed coming out of the shifter, this lever is made for traditional brakes.
The newer style shifters with the shifter cables run under the tape pull more brake cable per pull than the older levers. So, if you were to use a Dura Ace 9000 caliper with a Dura Ace 7800 lever, the lever feel would be too mushy. So mushy in fact that it’s dangerous. If you did the reverse, with a 9000 lever and a 7800 caliper, the lever feel is very firm and lacks power and modulation. It isn’t as dangerous as an old lever with a new brake, but is obviously less than ideal.
Because SRAM, Campy, and most aftermarket brakes, such as Ciamillo brakes for example, use the old traditional cable pull ratio, they are unsafe to run with the new style Shimano brake levers. However, they will all work just fine with the old style Shimano levers.
This also means that current Campy and SRAM brakes can be used interchangeably with levers from either company, but keep in mind that they are optimized for use with their own respective levers.