big landslip at new mills and bus replacement for a portion of the journey so you’d struggle with a bike! Would be worth checking if you are trying to get to Hope valley!
You can get to Marple direct from Manchester. There are also occasional (fewer than normal) trains to New Mills Central although New Mills Newtown (on the Buxton line) is unaffected.
The rest of the Hope Valley from Chinley > Edale > Hope etc is still served direct from Piccadilly but the trains go out on the fast line via Hazel Grove. Looks weird and wrong at first but if it says Sheffield via Hope Valley, you’ll start the HV at Chinley then call at all the normal places.
The bit that is currently completely out of action due to landslips is between New Mills and Chinley. And what you can’t do is go direct from Marple or New Mills out into the Hope Valley – not without a bus replacement. Which is bloody annoying!