On Good Friday and Easter Sat and Sunday I am cycling the UK cycle route 72 following the path of Hadrian's wall between England and Scotland. I've been doing a lot of cycling recently to get fit enough for this and I seem to have perminantly sore quadriceps.

Tomorrow is the day before the three day run. Should I rest and rest my quads or should I get on the bike to stop them freezing up? Also any ideas for sore muscles?

DOMS means your muscles are inflamed. Working them more will just break them down more and make it worse. Remember muscle grows during recovery, not during the workout. Soreness is a sign you need to rest, preferably until the soreness is gone and then another day or so to make sure. Drink lots of water and eat protein sources high in glycine and glutamine. If stiffness is a problem get a massage.

you probably should have rested two to three days before and had a light workout the day before the race. if you're that sore, i'd take a day off before the race.