My daughter is an average sized 11 year old and is too big for her 24” Orbea.
I’m trying to get her a full sus bike second hand for our summer trip to Morzine.

I know she’s about the right size for a Small adult 26” bike but I keep seeing XS adult bikes with 27.5.

I’m tempted by the 27.5 option so all our wheels in the family are the same size but I don’t want to saddle her with something that feels like she is hauling cart wheels around.

We’re at the far end of SW Wales so trying before we buy isn’t likely as the market round here is very small for mtbs.

Anyone out there with smaller people on 27.5…good or bad points?

cheers

There’s not a huuuuge difference between 26″ an 27.5″: you could almost say its about one and a half inches or less than two centimetres of axle height. My just-turned 11 is on a 26″ bike I built, that’s only using 26″ because I had a spare Crest wheelset to hand, the frame is designed around 650b.

I think the new kids bikes are all 650b because of two key reasons:
1) 650b is new, 26″ is old
2) They don’t want to stock more wheel sizes than required.

Mine, he’s 11 and average. He’s on a 27.5 Small. Fits well, rides great and gives compatibility with mine for parts etc.

My mate’s lad has been on 27.5 for a while probably since he was 11 and he’s not big at all. Fits him ok, he looks like a smaller adult on a 29er. He went straight from a 24″ bike.

If I were you I’d phone ahead, then drive to Cardiff and try out all the options in one day. Plenty of LBS here you could visit in one go many with lots of stock.

My largish just 10 year old is on an adult XS 27.5 frame on 26 wheels. Fits well.

If you’re bothered buy it and stick 26″ wheels on it

I was in exactly the same situation last year with my smallish 11yr old daughter. Got her an xxs Orbea with 27.5in wheels and it has been perfect. No problem at all.

My lad is 12 years old and stands 4″11. He made the jump from 24 to 27.5 without any problems….. In fact I think its made him progress quicker as he says the bike rolls quicker giving him more confidence to hit rougher ground….go for it….. Worse case scenario is you can just put some 26″ wheels on the bike if she doesn’t like it.

Mrs_oab is 5′. So the average 11-12 year old.

She rode: XS / 12.5″ Cannondale F900sl (26″ wheels), then Trek Superfly 13″ (27.5″) and now Giant Liv Lust X’s (27.5″).

I would look more at the minutiae of geometry, including a sit on and try, rather than wheel size. When you are smaller every mm of geometry changes makes a disproportionally bigger difference.

26er Cannondale Vs 27.5 Trek

rossburton

There’s not a huuuuge difference between 26″ an 27.5″: you could almost say its about one and a half inches or less than two centimetres of axle height.

Even less than that – there’s 25mm (less than an inch) difference in outside diameter – so only 12.5mm difference in axle height on the same bike – and in practice 27.5″ bikes will drop the BB a little more than 26″.

If you can get a 27.5 bike to fit, go for it, will make the upgrade path a lot easier when you need a larger frame too.

My 10 year old daughter rides my wife’s Specialized Ruse which is either a small or medium, can’t remember which. We’ve done Forest of Dean, etc no problems.

Oh, and fwiw once you’ve worked out stack/reach type stuff you soon realise certain brands are not small enough at all.

Those that are:
Trek
Kona
Giant
Juliana

When we bought the Trek the dealer (Roots cycles) did a bike fit recreate if the Trek for mrs_oab and from that we took the plunge despite her not seeing a small or X’s.

I personally would go 27.5″ , just for obselesance of 26″.

My 10 1/2yo daughter has been on an xs Trek Marlin 27.5″ for the last year. She’s about 5’2″ at the moment- not sure how tall she was when we got her bike last year. She had been on a 20″ but combined with a growth spurt and not riding for a while, when she got back to it, it was comedically too small. Looked at some 24″ as the next stage but she was almost at the limits of that.

For a while the main issue was the width of the bars- she was holding them a fair way in but didn’t want them cut down. As she’s grown over the last year she’s started to use the full width more

Thanks for all the comments folks.
Seems I’m probably worrying too much!

Good comment re bars – our latest giant came with huuuuge bars, even for me. Mrs_oab now has some weeny shoulder width bars fitted, that feel like old skool to me yet suit her perfectly.

I’ll leave this here as I think it’s a classic example of a bike that would be suitable for your purpose:

Latest Classified Ads

My (admittedly massive*) 9 year old is on a xs ragley blue pig 27.5er.

Seems to be doing well on it.  Loves the bigger wheels. Dropper posts and relatively low BBs help.

*Bigger than your average 11 year old.

Sorry, the link was to the Banshee Spitfire listed in the classified ads.

My lads (11yo) Spesh Pitch XS wheelbase is a little short, meaning that his feet hit the front wheel very easily when turning the bars. His friends Marin has much better clearance.
He now rides my Stanton Switchback gen1 16.5″ when we go to any trail centre. The hydraulic brakes and far superior forks have made his riding much more enjoyable. A very expensive bike for a kid I know, but its my old one and it was sitting in garage doing nothing and I couldnt bring myself to sell it! He’s only allowed to ride it with me on rides though 🙂

My daughter moved up to an XS Kona Blast a few weeks before her 10th birthday. Other than fitting a set of 680 bars that I had lying around and a youth saddle, it fitted her perfectly fine straight away.

My 10yr old has been riding a 27.5 with 26″ wheels for almost a year. It’s a previous model Aeris MK1.5 so its long and low to start.

He’s using 142mm cranks preventing pedal strikes.
He could easily use 27.5 now but he likes the smaller wheels for whips and the Spank Race rims are nearly indestructible with his weight (35kg fully kitted up)

It’s been great for everything from a Purbeck gravel ride (with forks and shock locked and set at 140 on the back) to pro-line DH at Dyfi and Revs… rolls faster, climbs better and descends faster though it took him a month or so to get used to the extra length on jumps

My wife is 5′ and rides a small Capra with 27.5 wheels no problem. She has still got he’s xs Reign which I did message you about on your wanted ad. I guess it wasn’t what you wanted.