This website is a scam.
Looking back, I should have recognized the warning signs. They replied to emails after midnight UK time, suggesting they were not actually based in the UK, and they required payment by bank transfer rather than by credit card, which offers buyer protection. Despite all the red flags, I unfortunately fell for it.
If you are unlucky enough to place an order with them, do not fall for the next scam they will try. After taking your money, they may ask you to pay an additional £1,000 "insurance deposit" to a company called Allied Transport Logistics. Unsurprisingly, they also insist on payment by bank transfer rather than credit card.
The last message I received stated that if I did not pay the £1,000, they would have to dispose of the bike. Well, good luck disposing of an imaginary motorcycle that never existed in the first place.
I take full responsibility for not paying attention to all the warning signs. However, I hope this review helps others avoid making the same mistake and losing their money.