The easiest option is to thread a small allen key into the hose once you can see it and pull it through that way.

oops

Thanks everyone!
We rode all the Brechfa routes, two coastal rides and Afan, which was an unbelievably good trail for a centre. Unfortunately I lost phone signal, so I missed your later suggestions. :( We'll have to go back

We're staying just east of Carmarthen if that's any help. Thanks

Machynlleth to Centre of Alternative Technology may be worth a look.

Well worth while!

Mainly the howling gale and pouring rain. Otherwise, I have no excuse.