Anyone know if it’s worth changing the twist shifter on a Beinn to an x3 trigger? 7yo firstborn doesn’t seem to change gears ever and I’m not sure whether this might help.

All our kids took a while to warm up to changing gears. Grip shift imo is often too stiff for small hands unless you are religious about clean cables and lubed shifter. As soon as fingers are big enough (iirc @7yrs old!) then triggers work. We had X7 shifters as they were lighter and less lever throw.

The problem with the SRAM triggers is that the thumb is used for shifting up and down. Shimano triggers are easier as they use a finger and thumb, but then you have to change the derailleur as well

Next question – if I change the shifters, what grips? Are there suitable small-diameter lock ons?

Are there suitable small-diameter lock ons?

Yep but I’ve just cut down single lock on ones I had.
Stanley knife does the job and after you stick in the bar-ends it doesn’t need to be perfect.

I’ve changed grip shifts on the kids bikes to 7spd shimano triggers as my kids found these easier, though there is a still some challenge with my youngest as they do require some thumb strength to shift up the cassette.

Anyone know if the x3 trigger is made of cheese?

Yeah trouble is thumb strength it takes to push them. My eldest struggled going from gripshift to triggers, she found twisting them much easier. Also struggles with the up and down direction on triggers whereas gripshift was a bit easier to get her head around.

Bin the gripshit. Seriously the worst way for kids to change gears.
X3 or x4 worked fine with both my kids Islas.

Spank do lock ons specifically for kids, very nice.

I found the opposite, tried my eldest with triggers to start, she didn’t like it, fitted a gripshift and she can operate it just fine…

It is worth noting that she still needs prompting to change gear though, some kids don’t seem to link legs spinning at a trillion rpm with the idea of a slightly higher gear…

Went x4 trigger for my daughter when we passed her brothers bike down to her as the gripshift was playing up. She took to it very quickly. Unfortunately the older brother then wanted triggers on his new mountain bike, became quite costly. Daughter was six when we updated the shifter.

+1 for the Spank Grom grips, they’re great.

I think the Groms are slightly bigger diameter than the rebadged ODI grips on the Hybrid of Doom.

A pair of Ruffians should do, shouldn’t it?