My kid using a £15 carbon bar on his XC bike…. I bought 2 as I was planning to test one before risking it but when I cut down his bars it became obvious it was more than strong enough for a kid!
Equally there are some chinese Stems (badged wake) .. again wouldn’t suggest use for an adult DH racer…. but they are £5….. (delivered) and were much lighter than the stem came with his 24er (and also much shorter)
Double check pedals…. I THINK the Orbea are 9/16ths…. just check they didn’t stick 1/2″ on the 20….
I bought some AEST superlight (Ti axle)… these are well described by superlight … they come with some aggressive pins which I filed down/rounded off. These have lasted well… they needed bending back a few times due to rock strikes but have bent back with mole grips no problem. I know I said they are light… but they are really really light. They also fit well up to size 2-3 (kid is currently size 13 and they are still good)
He is now well into territory where staying on the bike is more important… so I’m going to replace the pins… he had an interesting moment where he lost grip on a big jump riding at FOD …
On his other (Enduro bike he has some DMR V12’s that came with it) … I’m not changing for the sake of it but some V8’s would probably also be good.