Originally Posted by
Lemond1985
Some people have said that anything indexed that's over 8 speeds, feels like friction shifting anyway, because the gears are so close together. Regarding indexed 10 speed thumb shifters, I don't think there is any option than Microshift. Just cheapo $20 friction shifters, or something vintage. Or bar end shifters.
Shimano makes them.
https://www.universalcycles.com/shop...7&category=774
Personally, I would get 9 speed triggers (9 speed road and MTN have the same cable pull ratios) or swap the 10 speed RD with a mountain RD that is compatible with MTN triggers.
I have also read that mounting the thumbies upside down is more comfortable, but you will also have to run them on opposite side (right-left). It is said that was common in the 80’s before triggers were common.