>>2106918You can compress high volume fabrics using a plastic bag, you fold them as usual even if they take up a lot of space then you put them inside a bag, make a knot that allows just a bit of air to pass and then compress the bag with your weight to push all the air out, then just make the knot tighter so air can't get back inside. This method works for anything from sleeping bags to clothes like jackets or sweaters. When you're done strap them to the back of the bike.
