Yesterday evening I had a small problem with my Mango which meant I couldn't ride it home, so I rode my old two wheel Pashley PDQ recumbent instead. This has been languishing in the back of the ligfietsgarage for six months since my Mango was ready to ride and I abandoned my old friend.
It actually felt great to ride the old bike again. I've made many journeys on it in the past and it was a return to a very familiar feeling. In fact, it was better than it had been for a while, because not long before it was "abandoned" I'd spent quite a bit of time sorting it out with new chain, cassette, chainring, mudguards, even a new fork to replace the rusty looking one I was using (thanks to Tom who gave me his spare PDQ fork several years ago). The PDQ felt very light-weight after riding my Mango, acceleration between 0 and 20 km/h seemed instant. I enjoyed riding it. I had a bit of a tailwind for going home, and it took just 56 minutes to get home last night on the PDQ. For me, that's a good time in real conditions over 30 km on the PDQ.
Of course this morning the same tailwind was a headwind. It took me an hour and 3 minutes to get to work. Again not too bad on that bike with a headwind, but then there is what happens when I ride the Mango instead...
Both days have had much the same weather. Dry with a Northerly wind (i.e. blowing from work towards home). Yesterday morning it took just 53 minutes to get to work against the headwind in the Mango, and this evening in the newly repaired Mango it took just 49 minutes and 10 seconds to get home again. Those are average door to door speeds of 33.5 km/h into the wind and 36 km/h with the wind vs. 28 km/h and 32 km/h on the PDQ. I'm quicker in the Mango with a headwind than on the PDQ with a tailwind. It's a speed difference of between 12 and 20% - the greater difference being with a headwind, which is what you'd expect with an improvement in aerodynamics. A tailwind tends to even different bikes out.
The improvement in efficiency is amazing. Compared with a normal bike, or even most recumbents, the Mango allows you to propel yourself further and faster for the same effort.
This got me thinking. Some years ago I came across Walter Zorn's excellent bicycle speed calculator on his website. Unfortunately, I understand that Walter passed away last year. While his personal website is still viewable, not all of his excellent work is. In particular, his bicycle power and speed calculator has been offline for some time and I could only find it on the wayback machine.
While Walter's calculator has always had the Quest Velomobile in it as an option, it didn't have an option for the Mango. I've made a modified version which includes the Mango velomobile taking figures for Mango aerodynamics from other websites and the weights of real Mangos, including my heavy one fitted with the wonderfully puncture resistant Marathon Plus tyres (I ought to change them now that winter is over).
The calculator also still includes many other types of bikes, from upright roadsters through racing and time-trial machines and a variety of recumbents. One of the options is for a short wheel-base touring bike which produces numbers which are reasonably believable for my PDQ. By comparison, the option I added for my Mango gives just about the right difference in speed from that "PDQ" option. It's interesting also to compare with newer, lighter Mangos, and to see what happens with a hill. Even in relatively flat places like the Netherlands, there is never a truly flat surface, so weight is always an issue. The light weight of the Mango Sport means that it really comes into its own with even the slightest of uphill gradients, especially when compared with heavier velomobiles.
The photos show me on my PDQ somewhere with rolling hills between Cambridge and London back in 2006, and my colleague Arjen test riding a newly produced Mango Sport earlier today on a cycle path in our industrial estate. I wrote about commuting speeds before. The infrastructure here also helps a great deal. NL is a great place to live if you like to cycle fast. Read my review of the Sinner Mango Velomobile.
Crossrail for Bikes - Dave Hill gets it Wrong ?
16 hours ago