Kids Bike - what next?

[Ratty]

16 minutes ago, RahulM said:

Oh wow, he is quite tall for his age. My son is 8 but about 125cm. Would you reckon 20cm for that height is ok ? Sorry for hijacking your thread but google search gives many opinions. TIA.

Yes, he is very tall for his age, but then his big brother who is 17 is now 6f2.

Depending on which bike you buy, he could ride a 20 or 24 inch.  For example the Specialized Riprock they recommend for kids between 119 and 142cm's.  My son has been riding his for 2 years now.   You might find he will outgrow a 20 inch too quickly.

[Kuys]

My daughter, 12, 1.47cm, rides a small 29er with a reach of 420, 45mm stem and 650mm handlebar. Perfect fit. 
Dont underestimate effect of handlebar width, most kids rides bikes with handlebars too wide for them which makes the bike too big for them (their arms are too short to move through the wide arc the wider handlebar makes when turning)

[ChrisF]

On 2/3/2026 at 9:00 AM, Shebeen said:

Disagree on this one. My 11yr old is rocking his 3x10 on an XS 26" just fine. FD is the easiest thing to adjust and kids should learn about cross chaining -  the costs to replace this is serious low bang for buck in my mind. (happy to be slated on this one, you guys "upgrading" to 1x makes the 2nd hand market awesome!)

 

Jeepers, you clearly are missing the whole point ...

 

UPGRADE, then upgrade some more, then go 1x .....

 

Until you have a "kids bike" worth a fraction of the upgrades .... hanging in the rafters as a spare sparts for your bike .....

[quade]

On 2/3/2026 at 7:31 PM, Ratty said:

I have been watching what bikes all the slightly older kids are riding.  Doing the XCO race in Feb so will ask around then.

We were also at trail seeker, and sounds like we are in a similar boat.

If I were in your shoes I would be looking for a  XS or S Carbon frame hardtail, older quick release wheel are fine (ideally carbon or lightweight aluminium) with XT or better components....that is good starting block, and the bike wont disadvantage him against the other riders at that XCO level

It will be cheaper this way as it won't last him long if he grows fast, our kids are last 2 years before jumping to bigger sizes at that age, frame swaps are good, but cheaper to buy a whole new 2nd bike sometimes.

[RahulM]

On 2/2/2026 at 10:25 AM, amac said:

Buy 2nd hand. Speak to people close to schools/provincial racing. They will know who will be getting onto bigger bikes and what will be coming available. 

I am not OP but second hand market seems to be dominated mainly by shops and prices are not too far off new prices. Hardly any private sellers. I put up my son's bike for almost 1/4th of price I paid so it is confusing as to how these shops keep up the prices so high. 

[amac]

20 hours ago, RahulM said:

I am not OP but second hand market seems to be dominated mainly by shops and prices are not too far off new prices. Hardly any private sellers. I put up my son's bike for almost 1/4th of price I paid so it is confusing as to how these shops keep up the prices so high. 

Kids outgrow bikes in 18 months to two years, so go to kids events, identify which kids have good bikes and discuss buying when the older kids get replacement bikes. When kids are young, you trade bikes easily without losing much money, because the good stuff holds value. When they get older it's much more difficult.

[Alexis]

On 2/4/2026 at 11:39 AM, RahulM said:

Oh wow, he is quite tall for his age. My son is 8 but about 125cm. Would you reckon 20cm for that height is ok ? Sorry for hijacking your thread but google search gives many opinions. TIA.

My 6 year old is 120cm and I've just bought her the Avalanche Flash 20". Rigid Fork, hydraulic brakes, 7 speed, Shimano components. R5,4k. Almost R600 cheaper than online R5999 price point. And I researched the hell out of it.  Advice I got was they will bounce around on sus, and obvs good to start off using body for suspension. For her age - 3 speed would even work as its going to be her second race this Sat. But its nigh impossible to get those specs without weight. She weighs about 22kgs. 20inch is definitely the size bracket for your son. Depending on how fast he grows - if its anything like mine - bank on jumping up sizes every year for now. She is on the lowest her seat post can go and in fact, we even cut the last bit so that it can go lower so she can put more than the tip of her toes on the ground to feel more confident. So its definitely big enough. Random input from the side.