After buying two Bromptons I found myself with rather a lot of bikes, and was able to compare their performance on my regular commute on the Atlantic coast of France. I live in Hennebont and commute through the town of Lorient to my office on an industrial estate ten kilometres to the west. My conclusions aren’t rigorously scientific, but I have corrected for differences in cycle computers and only included simple rides on the same route, without detours for shopping etc. I have also excluded exceptional weather conditions (strong winds, ice, etc) and night rides (some bikes have dynamos and some battery lights).
Most of my data comes from this daily commuting round trip of 42.6km (27 miles), mainly on rural roads. Because Lorient is on a river estuary and there are not many bridges over the river Scorff, there are few routes to choose from.The total climb for the round trip is about 500 metres (1,600 feet) with one steep hill, so single-speed bikes are not a good option. After 3,391 kilometres, I can report that the speed variation between the fastest and slowest bikes is only 3.7mph.
On this commute, I usually cycle both ways during the summer, but I tend to use the Brompton plus the train in winter to avoid a long ride in the dark.When cycling, I allow about an hour each way. By comparison, the train plus Brompton takes five minutes to the station, five minutes waiting, 17 minutes on the train and ten minutes riding to work, making 37 minutes in total. As the evening train doesn’t stop at Gestel, my nearest station, I have to ride to Lorient, increasing the journey to about 47 minutes. It is possible to get to work by bus, but that takes 90 minutes each way.When I get a lift by car, the trip takes about 30 minutes on back roads – the quickest car route is on the motorway, but this is risky because there are frequent jams.The best ‘commute’ of all is working from home using my ADSL router to transmit documents over the net!
Research
Martin's experience will be familiar to commuters worldwide. The motorway is fast, but can be unreliable, train/bike comes second, but needs careful planning, bike is slower but more predictable, the bus is slowest of all.
From my research, the four factors that most affect bike speed are riding position, gear type (hub or derailleur), wheel size and tyre type. Apart from the huge difference between road-going Martin’s experience will be familiar to commuters worldwide.The motorway is fast, but can be unreliable, train/bike comes second, but needs careful slicks and off-road planning, bike is slower but more predictable, the bus is slowest of all knobblies (bikes 3 and 10 are the same!) I have not investigated the difference between different brands of tyre, but this is probably significant.Wind resistance is important too.The two fastest bikes had aerodynamic drop handlebars, and one of these was the Moulton, which proved 2.5km/hr slower with ordinary straight bars. Wheel size is less important, but small wheels would seem to be slightly less efficient. Comparing bikes in positions 1 and 2, the Moulton is a little slower, but it is also heavier, has fewer gears and a smaller top gear sprocket (11-tooth). Another interesting pair are the Roadster in position 4 and the SP Brompton in position 8. Both share the same hub gear, but the Brompton is noticeably slower. Hub gears seem to be slightly less efficient, although bikes ranked 3 and 4 achieved very similar results, with few differences, except for the gears. On the other hand, the two Moultons (one with 7-speed derailleur and the other with 7-speed Nexus hub) performed very differently.The Nexus was very inefficient when new, so after a few hundred kilometres I took it apart and greased it, but it’s still noticeably less efficient than the oil-lubricated Sturmey S5-2.
…I use one of the Bromptons when there’s a likelihood of other transport being involved…
Best Commuter?
Which bike gets the most use? Neither of the fastest two.Though the derailleur- geared Moulton is fast and comfortable, it is only suitable for good roads and fine weather, or the derailleur will pick up muck too quickly. I tend to choose one of the Bromptons when there is a likelihood of other transport being involved, and the roadster gets a lot of use because it can carry a lot of shopping and the wide tyres enable me to explore paths and tracks. But the bike I used most in 2004 was the Moulton with the Nexus 7-speed hub – it also has a rear roller brake and hub dynamo that work in all weathers, and I appreciate the comfort from the suspension.
Editor’s Note: If, like Martin, you are expecting to commute daily, don’t be scared off by small wheels. They really do make very little difference, and a smaller, lighter folding bike can be a more flexible solution. Even on this long ride, the Moulton is only three minutes slower than the conventional lightweight racing bike. On a shorter more urban commute, the tables could be reversed.Tyre type and quality are more influential than tyre diameter. So don’t choose an MTB! The gear system is important too, and Martin’s figures seem to confirm that the Nexus 7-speed hub is relatively inefficient, the Sturmey Archer 5-speed less so, and the Brompton/SRAM 3
A to B 48 – June 2005
