I have the super detailed Hitachi Class 395 'Chris Hoy' and the White Olympic version also. With a full length six car train traction can be a problem with the tyres slipping and loosing grip. I have discovered that if you replace the other untyred wheelset on the power bogie with a set with traction tyres then the wheels don't slip and stick to the track like glue. They also fit the cheaper Railroad versions also. The wheelsets are available on Ebay from Peter's Spares for around a fiver: http://www.ebay.co.uk/itm/331782678175