anyone know if the older (2009) mavic crossmax wheels can have there hubs swapped out for something like hope pro 2’s
I was told the newer crossmax will only take mavic hubs
and if the answer to the 1st part is no,
how easy are mavic wheels to repair or service ?
are parts readily available ?

No.
Yes,very easy.
Depends which parts you need.

What’s the problem with them?

Why wouldn’t you be able to change the hub and spokes? It’s just a rim like every other rim out there.

Depends exactly which crossmax, but if you’re sure its the 2009 then almost definitely not possible to replace with a hope

it could, at least in theory, be done with deemax and a couple of the muck older other wheels

hub spares should be no problem to get – for 2009 wheels rims and spokes will be topping out soon, as only guarantee spare parts supply for 5 years after model cessation

do you exactly which model they are – that will let me tell you more

TBH, If I was buying wheels tomorrow I’d go for hope hubs and the new 821 tubeless rims

been offered a set for 100 quid,
says they run true and although running freely they aren’t running as new !
yes they are older wheels but this is my 1st go at building a bike so im not going over the top to start,
the bikes around a 09/10 model anyway

good price – new bearings should make all the difference, though likely new free hub body as well (or a hub doctor) which is around 40 quid

and with reguards to the numbers on the rims,, ei, 821’s
I was told the 1st digit is the model, ei, the bigger the digit the better the wheel, and the 2nd 2 digits was the rim thickness,, is this also true ?
still new to this game and to say its a mine field is an understatement ! 🙄

Correct

first number, evens is tubeless, odd is not, higher the better

second two, internal rim width

though you can can never go wrong with hope hoops on stans or mavic 521

I got my older Crossmax Enduro rear hub rebuilt a while back, it was pretty slow- frankly Mavic France did their best to hinder it, refusing to offer any help other than “post both wheels to france”. But Mavic UK were excellent, one of their chaps actually spotted me moaning on here and provided me with the info I needed, then my local Mavic shop got the bits with no fuss. Was quite impressed.

So why can’t the hubs be swapped? I’m confused.

Not many spokes, and proprietary zircal spokes, with a coarse alu thread. You may be able to use the inserts from an XM819, but I don’t think they’re the same.

The rims have threads in for their nipples which are specific to their spokes (and captive on the spoke) which will only fit their hubs.

Makes more sense if you look at the pics below