Questions about wheel use

[Nika]

Hi there,
I am posting as I have little experience with winter whites (I have had three syrians so far, this is my first dwarf)!
My question is mainly about wheel use. I do not see Pepper (3-4 months old winter white) use his wheel very much - it is the same wheel I have had for all my hamsters, and it made me wonder if it's not the most ideal wheel for such a small hamster. I don't remember the exact wheel I got, but it may be/is very much like the Trixie solid wooden wheel (28cm in diameter). He is definitely able to move it, I have seen him in it for brief amounts of time, but he is not regularly using it at all (as far as I can tell anyways). He seems to be way more interested in scratching the back of the wheel and chewing on its stand.
I'm a bit worried he won't get enough exercise or that there is some other issue he has with the wheel.
He is housed in a detolf, all by himself, so it's a nice big cage for such a little ham. He seems to be completely healthy otherwise, he loves tunnels and digging, he is getting used to being handled, and he seems to be eating and drinking well!
Any ideas about what the problem could be? Is he just not interested in running?