Hi All I have recently purchased a Hornby Class 91 “Durham Cathedral”. I have a large collection of Hornby locos ranging from older models up to the likes of the re-tooled HST - all running on a DCC layout. Every model I have purchased has been excellent and I’ve never had any issues up until now. I had been looking forward to the arrival of the Class 91 after the excellent HST but unfortunately it has been a disappointment. Whilst the loco is finished superbly it is not a good runner. My layout is not huge, is made of all Hornby set track pieces and does not have many complicated track configurations. Since it’s arrival the Class 91 has struggled to cope with it. It is a very “clunky” runner particularly over point work where is often derails. It also struggles with 2nd and 3rd radius curves. My track work is level when a spirit level is laid across it and I rarely have any derailments. I have spent ages working to improve the sections that the Class 91 was not happy with but it has made little difference. This afternoon I set my HST running and it didn’t put a foot wrong. I then set the Class 91 running at the same speed on the same track and it derailed twice, wiped out the barriers on my level crossing and then shorted out my DCC controller so it required a reset as the loco had essentially left the track. This I’m afraid was the last straw and it is going back for a refund. It just would not run reliably enough - you have to watch it constantly. Issue seems to be with the front bogie that has very little lateral movement so any slight undulation in the track makes the lead wheels lift off the rails and then derail. It also gets bounced across point work hence the clunking noises. A real shame all round - hoping the Class 87 to replace it is altogether better. Regards