Can anyone explain why, after a 25 miles of mountain bike ride, Ive put on 1/4 of a stone?

I know if you lift weights the muscle ways more than fat but this is cycleing, wtf going on ? that cant be right can it.

ignore the "of"

Because after riding for that long your muscles start to tear, then when they are repaired they become bigger and stronger. Muscle Weighs more than fat so, In the intention of losing weight you actually gained muscle mass. (You also lost the fat that you might have had. But the muscle mass was a larger number than the fat lost)

If your exercising to tone up, its best not to use scales as a measurement; like you said, muscle mass weighs more than fat so you are not going to get an satisfactory results curve.
Look in the mirror and pinch your fatty areas; I know it sounds a bit vain, but after a bit you will notice a real difference and that will give you more motivation to continue

cycling also puts on muscle mass since are working out regardless. That's why there are spinning classes out there - spinning is basically cycling on a stationary bike.

so yes, it's probably muscle mass.

Well, I would of thought that when you cycle it builds up the mussles in your legs,
well hope it right :s
xx

simple, you drank more water than you sweated out. also, scales jump around and are not all that accurate.

Have you thought about getting off the bike before re-weighing?

Your scales are knackered.

DID you Drink water??

the closer to the ground you are, the heavier you get. weigh yourself again sat on your bicycle.

wtf?

Cycling muscles up your legs

Take a shower, it's MUD.