In reply to gooberman-hill:
But going the wrong direction from Gardemoen..... and which station ?
Basically try any sports shop, with XXL being a large chain akin to Decathlon. Some garages as well, especially once you get away from town and towards Jotunheimen? Where in Jotunheimen - so you know where you're going through.
https://www.xxl.no/store-finder
Beware all sports shops will be shut on a Sunday, except a very small number attached to cafes...
Post edited at 17:05