When to go to XS frame
 

I have a son (7 years old) that I am riding every weekend with on Mt. Tam. He is a good rider, getting used to downhills, but a strong grinder up the mountain. We do 4-6 mile ascents.

He has been on a 20" Marin 14 speed, which is really a great bike. However, he is a very tall kid and the bike seems too small. I would also like to get him on a bike with triggers as the grip shifter for the front derailer is too hard to move for him, requiring a great labor whenever we change slope.

The problem? Decent bikes (front shock, 3 chainrings up front, decent shifters) are expensive. The logical path would be to move to 24", but I am horrified at spending $400+ then buying another bike in 2 years. I have heard people say buy an XS frame (13") built with a 24" wheel then get new wheels later.

I am at a loss and would appreciate any advice and suggestions.

when does your child move to a xs frame bike?

when he can safely ride it and can stand over the top tube with a bit of standover clearance, before that its unsafe

if you have the seat all the way down and he can't touch the ground then its way to big

go to your lbs and have his sit on a xs, unfortunatley the best thing would prolly be a womens bike cause they generally come smaller, but u'd have to find one in a color he would be cool with (most boys arn't down with pink)

as far as changing out wheels goes that would give a tad better standover, and assuming the bike has disc brakes I don't see why it wouldn't work, but getting 24" disc wheels will prolly be most of the cost of a 24" bike and on non-disc frame/wheels the brakes wouldnt' line up

there also exist 26" kids bikes that are in between a 24" and an adult xs, maybe harder to find in stock but they exist and are made by major brands (ie they arn'd walmart bikes)

Safty is the most important thing. If you can't fit "correctly" it's only a matter of time when he gets hurt. I have 3 boys that ride with me; 7 , 10, 13. My 13 year old has about outgrown is 13inch hardrock, so we though we might get my 10 year old onto the 26'' mtb. My 10 year old is kinda short, but he had a clearance over the top tube, Just not alot horizonaly (the bike tapers upward to the headtube quickly). Anyhow, he fell and broke his arm.

I wish I had not put him on the bigger bike. A broken arm cost me arround $1300 (with insurance), and the loss of my riding partner for a season. I'm just glad it wasn't worse.

Id'e spend whatever I could to make sure he was properly fitted.

You could also look for a set of trigger shifters to swap out for gripshift.

Thanks for the feedback. Took him to the LBS today, and they had a Specialized 13" with 24" wheels that gave him about 1.5" clearance over the top tube. I have decided to wait six months and see where he is rather than make a bad decision now. Your feedback has been very helpful

26" wheels were just way too big. Thanks!