My 12yo son will need a new bike soon.

He’s currently riding a Saracen Mantra, 24in wheels, and a really poor Suntour fork (massively overdamped in compression and rebound).

He’s about average height, maybe 145cm, skinny. Our riding is bridleway XC, some trail centre stuff. Not jumping, not racing.

I’m thinking his next bike will be an adult bike. Obvious choice would be a very small hardtail, with 27.5 wheels, maybe a Trek X-Calibre or something similar (got to be an air fork though). I think that would be around £5-700, used, or about £900 new.

However, we also have an old SC Juliana. It is in bits and needs a lot of work (and probably £500 in respray, bearings, fork and shock service etc) to get it rideable, so he can’t really try it first. It would have higher spec, though older, parts (XT, Revelations, Hope brakes etc). It would be lighter than any hardtail we could get for the same price (He’s very skinny so weight is important). Obviously would have the advantage of FS too.

But smaller wheels, older geometry, older components, etc.

WWYD?

All our youth bikes on the work fleet are 26″ wheels and not long, low and slack. Older MTB should be good, I’d do the mechanical stuff first and if he get’s on with it make it look pretty. They tyres on our work bikes are 1.5 inches wide and look like a small-block 8 for tread.

Juliana. If it fits of course.

My sons had my wife’s (re-sprayed) Five Diva and it worked really well.

Juliana. If it fits of course.

This (and he’ll grow into it)

But smaller wheels, older geometry, older components, etc.

For a 12 year old, this all means f-all.

Juliana refurb i reckon, it’s gonna be a great step up from a Saracen.
He’s going to have a growth spurt in a year or two, so you might want to wait until then before you move to something spendier and longer term.
Put my lad on my old refurbed Epic and he loves it even if it is a bit old school, it’s still way nicer and quicker than all his mates’ 700£ hardtails

Have a look on ChaiN Reaction as they had up to 30% off bikes.  I picked up a Vitus Nucleus for my 11 year old a couple of weeks ago.  Nothing else new could touch it for spec vs price.

If buying new a Vitus Nucleus is a great bike… I have tagged the more expensive VRS as the VRs are sold out in size S, but at 30% off they are relatively affordable even if you budget for Brand-X Ascend dropper post.

I run a School MTB Club and we bought a VR as a ‘loaner/demo’ and it has proved very popular, especially as we got a dropper post for it. Weight is reasonable, geo is great, forks work, brakes are good, Box 8 speed drivetrain is surprisingly good (VRS has Deore 10 speed which is even better) and they come with really good tyres.

*disclosure, I work for Wiggle/CRC and we own Vitus so (a) I was able to get us a good deal, and (b) you may consider e biased. But the Nucleus is an award winning bike and 30% off is definitely a good deal.

If it’s any use, I put my 12 Year old on a Scott Spark this year. It’s a size small, 27.5″.
He’s perched on it (currently 151cm) a bit but he’d definitely outgrown his 24″ and I was trying to find something he could grow into. He’s confident on a bike but definitely not into rad to the max DH.
I bought it last year when small’s were hard to come by. I reckoned an xs would be soon outgrown, and I could not find one anyway, and by going 27.5 he’s aligned with my bike rather than a 26″ which I don’t have many spares for.
I agree with the points above about kids not caring what they ride – they really don’t give a monkeys. 1x makes it simpler, and as long as stuff works well enough it’ll be reet.
I’d go with the Juliana refurb. But I wouldn’t bother chucking a respray at it and I’d just service it DIY.
If it needs parts, people on here are pretty generous with old kit. Start a build thread and see how it goes.

I’ve had a look at the Vitus.

After the experience with his current fork, I would need an awful lot of convincing to buy anything with a Suntour. (or i’d have to factor in replacing it).

Apart from that, it looks decent.

However I think it’d be too big for him for quite a while. Vitus suggest 160-170cm, about 6 inches taller than he is currently.

The Juliana refurb has the added advantage of MrsF seeing her old beloved bike getting used again.

“kids not caring what they ride – they really don’t give a monkeys”

I wasn’t suggesting he would care, in terms of it being new or old. I was thinking that he might actually get some benefit from newer stuff, more modern geometry and bigger wheels, because they might actually be better.

The Juliana is not in a state to just be cleaned off and ridden. It was completely disassembled many years ago, for a respray that never happened. Even the frame is in bits. So i need to get new bearings and bushes for the frame to start with. Might as well get it powder coated at the same time. a lot of components will then simply bolt on i guess.

a lot of components will then simply bolt on I guess.

Sounds like a pretty cool Dad and Son project, too.

Have a look on fb marketplace for small bikes, you get some decent stuff around that price point (or an optimist grand that’ll get bargained down to 750 after a few weeks).

Got a small liv embolden for my 11yo daughter recently for 750 and there was plenty of other stuff around that price.

My 10yold is 149cm and is just getting too big for his 24″, but isn’t quite big enough for the 26″ small Cotic Soul, I’ve bought to replace it. 27.5″ would, IMO, be too big.

I just got my daughter a norco sight youth. 27.5 Xs frame. Second hand but not used. 27.5 but put a 26inch on the rear a used a shorter airspring I had for the pike fork to drop the front end. Bike is a bit big but not much. She is 9 and 145cm. She can ride her mums Juliana small, no stand over which is the issue.

I would go for the Juliana and see if it fits. Can you use the 24 inch wheels you have and mullet it if stand over is an issue?

Whyte 806 Compact; Maybe one of these in XS.  My son at 155cm has a small one. Seems to be very good not great value though.

Also we have had Trek hardtails in the past which are really good value; such as a Marlin and are nicely compact.

After 2 Early Riders (20” & 24”) we put our tall 11 year old on a Nukeproof Cub Scout. He loves it.
Fortunately I have an old spare set of 26” wheels, so he can have one set for road/gravel and another for ‘proper’ off-road/MTB.

“isn’t quite big enough for the 26″ small Cotic Soul, I’ve bought to replace it. 27.5″ would, IMO, be too big”

Trek’s XS (Marlin and X-Calibre) hardtails have 27.5s and they’re recommending those for people well under 5ft, or from 137cm upwards. Not the only important measure of course, but its standover height would be 27.4in, slightly more than an Islabikes Creig26, which is said to be for 9+.

“Sounds like a pretty cool Dad and Son project, too.”

Yes, we spent a bit of time last night talking about it. I think he likes being able to choose colour, decals etc and i think/hope he’ll enjoy helping putting the thing together. It might give him more interest in the bike and, who knows, maybe he’ll even want to clean it himself!

However I think it’d be too big for him for quite a while. Vitus suggest 160-170cm, about 6 inches taller than he is currently.

Have you seen the Nucleus 26 youth bike? Recently moved my 146cm tall 9-yr old onto that and it’s a great spec for price and ideal size. We’ve got last year’s model which came with a different fork, I note the comments re Suntour fork but at that price you could factor in an upgrade if it bothers you that much.

GF, my 10 year old has just moved from a Crieg 24 to a Creig 26 and he does the same kind of riding that you describe above.

The difference that the bigger wheels makes is incredible, he’s significantly quicker on the 26 than the 24, and we’ll be able to sell it on for a good price when he grows out of it, but you know that already.

However, if we were in your situation with a Juliana refurb project as an option I think we would have defo opted for that.

My 10yr old is the same height as your 12yr old and his current bike is a size small Scott Scale 950 29er, fits his really well and he loves it. It has a Fox 32 rhythm air fork and sag & rebound are bang on for his 38.5kg frame.

My 8yr old who is around 136cm is on a size XS spesh rock hopper with 27.5″ wheels and is very confident on it. It has a Rockshox Judy air fork and it too is set up fine for his somewhat lighter 30kg skin & bones build.

Make of that what you will sizing wise.

my 11yr old daughter is on a 26er planetx jumping jack flash anniversary edition and loves it. shes pretty tall for her age at the moment.

I have just got a second whyte 603 in xs for £300. my daughters are now fighting over it. They are both just under 150cm but the taller 10yr old looks fine on it. The forks does seem a little notchy but haven’t tried to service it yet.

It is in really good condition, classic bought for the wife but never ridden in anger bike.

4’9” on a 29er? Really?