Dura Ace Rear Mech Compatibility

Question: So I need to now upgrade my "old" 9 speed DA on my Six13 Slice as my new Slice is a 10 ... since you have said that the DA vs Ultegra is not worth the $$'s now, but as an upgrade yes ... should I get the DA rear now for my new Slice and move the Ultegra over to my Six13? Will the chain rings and Front derailleur need to be changed over for the 10 speed as well or will what I have work? I do know that I will need to get new bar end shifters for my Six13 ... other things I am not thinking about?

Hi Titus,

OK, so you need a new rear mech, well now is the time to get the best you can afford and if that is a Dura Ace then go for it.

If you are using a Dura Ace 10 speed rear mech with all 9 speed equipment then there is no problems, it will work fine. The problems start when you mix some 9 speed and some 10 speed. 10 speed levers will not work with a 9 speed cassette; a 10 speed chain will not work on a 9 speed cassette or the other way round. A 9 speed chain will work on a 10 speed chain set and usually a 10 speed chain will work on a 9 speed chain set, but not always. Your shifters have to be the same as your cassette, so a 9 speed cassette has to have 9 speed shifters and the same with 10 speed. If you run a 10 speed cassette you must use a 10 speed chain.

So the Shimano Dura Ace rear mech will work with all your 9 speed kit, but if you start to change the other bits then you will be in trouble. Get the rear mech of your choice and change all the other bits when you can, but you will need to change the other bits at the same time.