"Cyclists have no right to cycle on footpaths away from the road but only commit an offence where local by-laws or traffic regulation orders create such an offence. Cyclists can ride on bridleways, but not on countryside footpaths. To do so is a civil tort, ie not a criminal matter, the landowner has to sue the transgressor for damages (of which there’s likely to be none)."
So it would appear it's not against the law to ride on a footpath but the land owner could take you to civil court and try to prosecute you for trespass.
This is correct, and very few such prosecutions are made, not least because most landowners don't really care about the cost of path maintenance where it is dealt with by the local authority. So it would only be publicly-owned land where the owner had an incentive, and local authorities haven't got the resources to take legal action over such minor matters.
However cycling on footpaths does have a downside, in that the ideal would be for suitable paths to be reclassified as bridleways but that isn't going to happen if all that the local authority hears is complaints from walkers about cyclists ignoring the rights of way. No cyclist ever seems to say that they have asked the local authority to reclassify a path, so the local authorities tend to view cycling on footpaths as the action of a small minority of hooligans.
Nobody ever mentions their local access forum, which are established to press local authorities to make improvements to rights of way. Nobody ever says they have organised a petition within their local mtb club. Nobody ever says they have approached the British Horse Society to see whether there is any common interest in reclassifying a particular path. Walkers and equestrians are very good at banding together to protect their interests. By comparison, mountain bikers are a dosorganised rabble, so it's no wonder that their interests don't get protected. The CTC takes a lot of subscriptions from mountain bikers, but as far as I can see it does little to protect their interests, and just about nothing about rights of way.