Originally Posted by
rekmeyata
The newer Tiagra 4700 did away with the thumb shifter button so it mimics the 105, Ultegra, and Dura Ace levers, whereas the Sora levers retain the thumb shifter button which bothers some people while others don't mind. The odd thing is that Claris uses a similar shift levers as the Tiagra and above levers have, why Sora didn't go that direction is beyond me.
But Sora
did go that way. Sora 3500, introduced in 2013, did away with the thumb button.
Getting back to the original question about Claris, I'm running 3x8 Claris shifters on my '86 Trek 300. They don't have a fit & finish that'll wow anyone, but they work well. I haven't put enough miles on that bike to test their durability.