I have used Simplex Retrofriction levers and they were the best friction levers I ever tried but although I wish to stick with DT (if I go that route)...I am not sure whether you can use them with 10 speed.
And how did it go? Smoothly? Could access all 10 gears with ease? I have only used Retrofriction levers with 7 gears....I looked on line...most people seemed to struggle beyond 7 speed...though not all... probably safer to stick with SL7900?
I have used Simplex Retrofriction levers and they were the best friction levers I ever tried but although I wish to stick with DT (if I go that route)...I am not sure whether you can use them with 10 speed.