You're sure to see dozens of cyclists in the first few miles of this route, which skirts Box Hill - the favoured climb of London-based road cyclists. NCN 22 goes round the side rather than over the top, but there's still a fair bit of climbing to do, particularly on the Mount out of Guildford. This is a well-designed route from south London (Coulsdon/Banstead) to Portsmouth, but note that it includes a number of gravelly unpaved sections. Touring bikes and hybrids will be fine, but road bikers will want to modify it to avoid too much jarring (or punctures). We'd suggest that it's best tackled over a weekend rather than a single day, returning to the start by train. If you have time to spare, you can take the ferry to the Isle of Wight for the short continuation of route 22 to Newport.