Triumph favourite faces a true test Ante-post JCB Triumph Hurdle gamble Londoner makes his eagerly-awaited debut over timber at Kempton tomorrow.Martin Pipe`s four-year-old, who showed useful form when trained on the Flat by Henry Cecil, will face seven rivals in the January Juvenile Novices` Hurdle.Londoner`s best efforts on the level came in the Stardom Stakes at Ascot as a juvenile, and the Glasgow Stakes at York the following season.He was beaten three-quarters of a length into fourth behind Atlantis Prince at the Berkshire track, while he was just one length behind Musha Merr when third on the Knavesmire.Among the opposition tomorrow is the Paul Nicholls-trained Rigmarole.The ex-French Fairy King gelding, who cost 55,000 guineas at the sales, comfortably accounted for a field of novices at Wetherby at the end of last month.Londoner is 8-1 favourite with William Hill for the Cheltenham race with Rigmarole available at 25-1.