According to Official Guinness Records,
The fastest journey from Land's End to John O'Groats on a conference bike was 28 days 8 hr and 27 min and was achieved by Team CoBi (UK), a group of 194 individuals from across the UK. The 1855.52 km (1159.7 miles) journey was completed on 29 August 2010.
Team CoBi used a seven-seater conference bike for the journey and visited six Cancer Research UK centres and institutes across the country. The journey raised over £30,000 for Cancer Research UK. Edward Guinness, member of the brewing family and one of the original signatories which agreed to support the creation of Guinness World Records, helped pedal the final half mile.
For a complete list of 2010 records, please visit 2010 Guinness Records in United Kingdom.