The seller now wants more money

westernpromise wrote: »

Unfortunately the OP is almost certainly in the wrong because the purported seller of the bike did not have proper legal title to it, and therefore it wasn't granny's to sell any more than it is mine to sell.

Having proper legal title doesn't come into it as there is nothing written into any law that states this is the case.

All that is required is that the seller must have the right to sell the goods and as far as the OP knew, this was the case as the seller stated that she would consult her family to see if the offer was acceptable.

If I put something up for auction at a local auction house and it sells then was the buyer acting illegally as at no time did the auction house have legal title to the goods?

shaun_from_Africa wrote: »

Having proper legal title doesn't come into it as there is nothing written into any law that states this is the case.

Incorrect, it's fundamental English common law that you can't sell something you don't own. If you pay for such a thing, such as a stolen car, it is you who the thief is robbing because the legitimate owner is entitled to have it back. You would then have to recover your money from the thief.

If I put something up for auction at a local auction house and it sells then was the buyer acting illegally as at no time did the auction house have legal title to the goods?

No, because you would sign something with the auction house whereby you warranted that you did have good title. The auction house would as part of its T&Cs disclaim liability for establishing whether this was true or not, i.e. caveat emptor. Auction houses don't claim to be the owners of goods; they act as agents for the owners.

westernpromise wrote: »

Incorrect, it's fundamental English common law that you can't sell something you don't own. If you pay for such a thing, such as a stolen car, it is you who the thief is robbing because the legitimate owner is entitled to have it back. You would then have to recover your money from the thief.

No, because you would sign something with the auction house whereby you warranted that you did have good title. The auction house would as part of its T&Cs disclaim liability for establishing whether this was true or not, i.e. caveat emptor. Auction houses don't claim to be the owners of goods; they act as agents for the owners.

Of course you can sell something that you don't own providing that the owner has given their permission for you do to so and this is something that probably happens thousands of times a week when family members advertise and sell something for another member of their family.
You stated that auction houses do this by acting as agents for the owner which is what the person selling the bike stated that they were doing, selling it on behalf of the owner and that she had consulted with them and the price offered was acceptable.

Despite your saying that it's "fundamental English common law" There is nothing in either the SOGA or CRA that states anything about needing good title to sell goods. They both state exactly the same thing:

(1) In a contract of sale, other than one to which subsection (3) below applies, there is an implied [F9term] on the part of the seller that in the case of a sale he has a right to sell the goods, and in the case of an agreement to sell he will have such a right at the time when the property is to pass.

in any other case, that the trader must have the right to sell or transfer the goods at the time when ownership of the goods is to be transferred.

How about this:
https://www.netlawman.co.uk/ia/selling-goods-non-owner

If a person is in possession of goods, with the consent of the owner, as a mercantile agent, any sale by that person is valid even if the owner does not provide express authorisation for the sale. This means that an innocent purchaser can gain good title to the items if wrongfully sold by the agent.

Examples of agents passing good title to buyers include car dealership scenarios, where the owner of a vehicle gives his consent to a dealer to try and sell the car on his behalf. The owner does not have to be consulted on the particular sale for the transaction to be valid.

If granny was given permission to sell the bike but she did it at too low a price, that is her fault and the OP can still get good title to it.

shaun_from_Africa wrote: »

Of course you can sell something that you don't own providing that the owner has given their permission for you do to so and this is something that probably happens thousands of times a week when family members advertise and sell something for another member of their family.
You stated that auction houses do this by acting as agents for the owner which is what the person selling the bike stated that they were doing, selling it on behalf of the owner and that she had consulted with them and the price offered was acceptable.

Quite. And the owner is trying to get the bike back by arguing that granny did not in fact have either title to or permission to sell it.

If this is established (in whatever way) to be true, he gets the bike back and the buyer's out of pocket to the tune of that bike. As this has happened because granny misled the OP, she owes the OP his loss.

If it is not true that she was not authorised to sell, then the OP keeps the bike.