Níl aon tóin tinn mar do thóin tinn féin
Yeah Deore 11 would have been better... but for kids, they dont care, stick them on a 6spd and they crank it up the hills anyway.I'm on Deore 10sp now, I would like a slightly wider range, Advent X or Deore 11sp would be nice.
The 10spd has a bit more leeway before the gear indexing goes out, 12spd is just too tight for adventurous kids and lower lever NX, nevermind SX has an abundance of play that doesn't make sense.
You are tall so your young fella is about to do some growing. Dont believe what the manufacturer says about the minimum height, take him to a bike shop and let him have a ride on a few (if they have any bikes).
Mine at 10 were on 27.7 small HT's, they were 150cm a year back at 13 and 14yrs and got a Med Canyon Spectral and M/L Remedy 8, now both around 160cm at 14 & 15 they have sprouted about 8-10cm in the last year... they will overtake the old bloke in 2021 at this rate.
He will easily go on a small 27.5 and you can make adjustments to make it fit, 32mm stem, slide the saddle forward, fit a cheap dropper, narrower bars and you might even stretch him to a Medium.
One of the people who bought my 2 x Kona Kula's, turned up with the little girl, an 8yr old girl. She fitted on the bike with the seat and dropper fully slammed, zero stem, narrower bars.... big grin, no idea she was full gravity chick rolling DHF/DHR WT front and back.