I'd like to buy my son a new bike for his 11th birthday. he's a very experienced rider and we go on lots of family bike ride - mainly on trails/disused railways etc rather than full on mountain biking due to younger siblings. However, I suspect he will get more into mountain biking with his mates but he also needs to ride in on the street up to the shops etc.
My query is what size to get him. He currently rides a Dawes Grind BMX 20 which to be honest is still ok, just getting a wee bit small, but he is fed up of standing up on long rides due to the low seat post and would like a bike with gears. He is currently 137.5 cm in height, but has been that for awhile so I suspect is due a growth spurt. 62cm inner leg. I was looking at getting him a Specialized Hotrock 24 which is, I believe, the size before adult size. However, as the recommended heaight range for this bike is 135-145 cm I am a bit concerned it won't last him long. So should we get him an adult 26 inch bike instead? Would it be too big for an on the small side 11 year old?
To be honest it wouldn't necessarily be the end of the world if it didn't last for that long as he has 2 younger sibling to pass it down to so I am happy to pay for a good make, but I'd like it to last him a year or so. So 24 or 26 inch? And recommendations?