How do you size a bike for a fast growing teenager?

slowlanejane

I was recently visited by nephew (16) who was instantly struck by my Bianchi. He isn't a sporty chap but living where he does in middle of nowhere in Cornwall, he does get about a fair bit on his bog-std cheapo MTB. And now he wants a roadie, oh sooo badly.

I would like to help him and can scrape a tiny budget, so I will start prowling sites and classifieds. Happy finding him a starter make / model of some description - roadie equivalent of an old banger to see how he gets on, then if he takes to it I'll consier a nicer model later.

My question what size bike do you buy a boy who is growing like a weed? Currently 5ft 6 or 7, when I last saw him just before xmas he was smaller than me and I'm only 5'4"

Any BR-ers with a suitable machine they'd like to offload in N Cornwall area, pls PM me!

Wh05apk

I have the same issue, my son is 13y/o but about 5'9" and has probably grown about 6-9" in the last year, he is looking for a road bike, as he is doing club runs on his Hardrock MTB he has been sized up as a top end 54cm, but we will get a 56cm and possibly use a shorter stem etc to allow a bit of growth, that should then give him room upto about 6', by then he will hopefully slow down his growth - or buy his own bike!!

saintdracula

Get him a cheap bike for now.

night_porter

If you look at most manufacturers "recommended size" you will see that each size of frame covers a few different heights. The fine tuning is done with the stem length (as suggested) and the seatpost. Try and get the largest size he can fit on then tweak as required as he grows.

Compact frames seem to offer the broadest range of rider sizes because the sloping top tube allows for a great variance in leg lengths.

Also whatever size you choose buy a 2nd hand one from ebay or similar and pay roughly what similar bikes go for (current market value). That way if you have to resell it you should recoup most of your money and open the door for a larger one.

bompington

Same way as you size anything else for a growing kid - buy him the biggest that reasonably fits, don't expect it to fit for long, and sell it second hand. You can put the saddle down & maybe get a short stem at first, then as he grows you can do the opposite - but he'll still probably grow out of it quickly. Although at 16 it is possible he might stop growing soon.

Super Domestique

Did the same for my growing son. He has a TDF and I fitted a shorter stem (80mm instead of the 110mm it came with) plus the water bottle bosses would not allow the seatpost to drop far enough at the time of purchase so I raided my spares bin and found one 50mm shorter which was ideal. (that was last summer and the shorter post would not be needed now and he is only 12)