Surplus to requirements. Four locking double-wheels. Video here: Say £45 collected only as it weighs 12kg. In Oakwood, Derby DE21.
I’m not sure if it’s designed for that but I just tried it and it works OK. Bike rolls on easily with two casters locked, might even work without locking as only about 15mm to roll up. I put it in gear to lock the bike to the stand, then unlock casters and it works ok. See photos. Cheers, Bill
Post it using www.postagesupermarket.com it should be under £10 via Parcel Force with their discounts...