Have I mentioned recently how much I hate grip shifters? You know, those twisty bicycle handgrips that shift gears while you wreck? Trigger, thumb, and plug shifters are much safer and as a bonus, easier to work on.
There may be some kind of super-high-quality grip shifters I’ve never seen before, but mostly they just seem like something that a marketing expert thought of for low-end and low-mid-range bikes. A “sounds like a good idea until you think about it for ten seconds” kind of thing. And they make a ten-minute cable replacement into an hour-long ordeal because the cheap plastic parts cracked and I had to dig around in my spare parts buckets. Fooey!
I had one when I was young—probably adolescence and young teen. As I recall, it worked pretty well and never required maintenance. That was in the ‘60s, so it’s likely that even a poor concept was implemented with more care and better materials. Seem to remember it feeling quite solid and operated smoothly. But I bet if it had failed it would have been a difficult repair.
I hate grip shifters. It’s not just the accidental shifting when braking (or turning, or not focusing on not-shifting) but the fact that they sound like high tech aliens.