Wednesday, 8 September 2010

10000 km with a real "green" alternative to driving

I've now ridden my Mango 10000 km since I first rode it, just under eleven months ago. That's about 910 km per month. I calculated before I left work today that I'd be a couple of km short of the magic figure if I rode home the usual way, so I took a detour through Assen to make up 2 km extra, and 10000 rolled onto the computer just as I passed my home.

It's been used for many day rides and a few races as well as my regular commute, and it's really worked very well for all these things.

The luggage space inside has been used for shopping, for vegetables I've bought from stalls at the side of the cycle path on my way home from work, and for my tent and sleeping bag when I've gone further from home. It's also pulled a trailer when there has been more to carry.

As I commuted all through winter (and also the Dutch summer), I've ridden my Mango through snow and rain, and it's also provided some some shade from the sun on days when the temperature was 37 C.

The Mango has done all these things, and done them all very well. It's just wonderful to be able to go faster for the same effort, even into headwinds which would otherwise be a bit dis-spiriting. This evening there was a strong head/side wind on the way home, but it didn't stop me cruising at 38-39 km/h without any difficulty at all.

And what does 10000 km represent in terms of fuel consumption for a car ? Well, if instead of riding in the Mango I'd driven our quite average car this distance then it would have consumed about 730 l (160 gallons / 192 US gallons) of petrol, costing over 1000 euros (about 90 euros per month), which would have put 1680 kg of CO2 into the atmosphere. My 60 km round trip commute would have consumed about 4.5 l per day, about 7 euros per day, and produced about 10 kg of CO2 for each commute.

If we'd invested €25000 or so in a shiny new "green" Toyota Prius, I'd have been able to get away with burning only about 2/3rds as much fuel. And to repay the loan over 5 years would cost around 500 euros per month and fuel cost around 60 euros per month.

Instead, with my €5500 Mango I've not had to buy any fuel at all, and if I had a loan then the repayments would have been similar to just the fuel cost for a car. My Mango consumes no fossil fuels (not even indirectly at a power station) and produces no CO2 emissions. It's the true green alternative, and it also keeps me fit - saving on the cost of the gym which perhaps I might have subscribed to if I lived in another world and didn't cycle regularly.

Governments around the world encourage people to sell existing cars and buy slightly more efficient models. Where is the comparable government help to buy a truly green vehicle ?

Sometimes people express concerns about the environmental cost of the glass fibre, epoxy, polyester, aluminium etc. used in construction of a velomobile. They're right to do so, as all these things do have a high embedded energy cost, and yes, there are some nasty chemicals involved as well. However, to build a car uses more of everything. The Mango necessarily has to be efficient with the low energy input available from a human (more than 100 W over a long period of time is difficult) vs. that available from an engine or motor (1 horsepower ~= 745 W, and powers over 100 hp are not uncommon for cars - i.e. cars can have 3 orders of magnitude more power available). The Mango weighs only around 30 kg (it depends on the model). This is necessary as rolling resistance and acceleration are dependent on weight, and it must require far less energy to move than a car. If the Mango weighed 1000 kg, it would take a huge effort ever to exceed 10 km/h (there's a calculator here that you can play with). The low weight also means the embedded energy cost is lower simply because fewer materials must be used.

Now a couple of things that I've changed about my Mango more recently. Several months ago I bought one of Peter's small lights to mount near the mirror. It took me ages to get around to mounting it on my Mango last week, but I'm very pleased with the result.

While the small light doesn't consume much electricity, and can't light up the road like the IQ Speed mounted in the front of my Mango, I can aim this light higher without dazzling oncoming cyclists and motorists and it is really very obvious from a distance. Both the IQ Speed and the small "daylight" LEDs in the front of my Mango are also lit in this photo, but the brightest from this angle is the small light next to the mirror. I think it makes the Mango easier to see (to those people for whom 2.5 m of bright yellow simply isn't enough...). It does this while drawing very little current so having a very slight effect on the battery.

Finally, for a couple of weeks I've had an annoying clonk noise with every push on the pedals. One after another, I've been tightening up this and that around the Mango and the clonk noise remained. Today at work Harry suggested it might be the bottom bracket bearing cups being lose. I tightened them and... At last - near silence again ! I'd not even considered these because they weren't obviously lose and I couldn't see where enough movement could come from to make a noise. If you've a mysterious clonk noise when pedaling on a bike with this type of bottom bracket, try tightening up the cups.

You can find out more about the Mango on the manufacturer's website. Yes, I do work there, but I do so because it's really a great product.

I was of course hoping for 1000 km per month in the Mango. However, I ride other bikes as well, and my personal total is easily over 1000 km per month if these are included.
Read my review of the Sinner Mango Velomobile.

11 comments:

scruss said...

Congratulations on the 10k, David! There's someone here in Toronto who rides a Mango, and it looks very nifty.

Stewart
(on his staid Batavus)

gingerbeard said...

hmmm, I am currently riding at a rate of 5000-6000 kms/year, just on a $1200 (500 euro) bike. Guess that makes me even greener.

still congrads on the distance, and the commitment.

Matt said...

Congrats on 10,000km. It's quite an achievement.

I really wish velomobiles caught on and took the place that cars do now. The world would be a seriously much better place. At over 5,000 Euros a pop that ain't going to happen. I know your Mangos are hand made and finished to a high quality level, but I wish they were ubiquitous and cheap.

And I still want to have a go.

ben said...

Hey David, I am interested in how the fiberglass shell is made for the mango. Can you show a video of this?

Klaus Mohn said...

Congratulations, David! The Mango is a really cool vehicle. You may have adressed this point, but here goes: how practical would it be for someone who lives in a tight, routinely traffic-choked urban core (Paris city centre)? I can't see myself sacrificing the agility, peripheral vision and "blend-in" factor of my traditional city bike. Is there a 'bent/velomobile solution for me?

(Unrelated question: do you make Klickfix baskets?)

Anonymous said...

Well done to both you and your Mango.

Mark Garrett, Bristol UK

ian... said...

Wow - mileage posts are popping up all over the blogosphere this month.

Congratulations on the 10k & what a stunning machine the Mango is. (I've got a bottom bracket to check now as well ;>D )

Pjotr320 said...

A good start David. Now keep pedalling and get it up to 25.000 :-)

kfg said...

BB bearing cups are the usual suspect with all kinds of BB.

The Clog said...

If your bottom bracket cups are loosening, they were likely not torqued sufficiently. However, your bottom bracket also may need facing to ensure that the cups are locking against the shell properly to achieve the previously mentioned torque requirements.

David Hembrow said...

kfg, The Clog: I'm surprised at your interest in this detail.

As it happens, I've worn out and replaced many bottom brackets in the past and would normally notice such a fault immediately. However, there's a reason why I didn't immediately pick up on this as a bottom bracket problem. The noise made was not similar to that I've had previously from bottom brackets and I couldn't feel the fault through my feet.

It was not a creaking sound due to sliding against a slightly dirty surface, but a solid "clonk."

You also have to take into account that it was not immediately obvious which direction the sound came from. In a velomobile, sounds travel through the frame before coming out where you least expect them and resonating. It can be very misleading. First of all, I tightened up bolts on the seat support as initially the sound seemed to be coming from almost exactly the opposite direction to its true source.

If you've not had this experience you probably won't understand it.