Sinner Mango Velomobile
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The Hembrow Cycling Holidays blog has stories about cycle routes in Drenthe.

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Sinner Mango Velomobile DIY ideas

The DIY ideas presented below are suitable not only for the Mango but also for many other velomobiles such as the Quest and Strada.

Any suggestions for DIY work must of course be at your own risk. If you do things incorrectly you could either damage your bike, or yourself. None of what is described below is difficult to do, but do take care.

This article is in three parts (this is the third part, with Do It Yourself suggestions), and has the following sections:

Adding a USB outlet

While I worked at Sinner I built a small circuit board which fitted inside the dashboard of the Mango to provide two USB outlets to charge telephones, GPS or other devices from the Mango battery.

USB adaptor from DealExtreme

It is no longer really worth building a circuit yourself to do this job as you can buy a circuit pre-assembled from China for less than the cost of the components to make it yourself. The price was under $2 including delivery when I wrote this - click on the photo to the right to buy one. This device is designed for 12 V operation, but I found it worked fine with the 6 V battery in the Mango and could handle things like being shorted out for a short period of time without trouble. DealExtreme have several other similar USB adaptors which claim to adapt 12 V to 5 V, but I recommend this one because it works. I've not tried the others with 6 V.

Now for how to connect it inside the Mango. First you need to make a connection to the metal contacts. They are not easy to solder. You can take the device apart, but it's messy and you potentially break it. Also, if it fails (it costs $2 - I don't know how long it'll last) then you'd have to repeat the same surgery to fit a new one. I recommend instead that you buy a socket with loose wires to fit it into. Pick from two different types on dealextreme, either this one or this one. Either will do the job.

I recommend fitting this after the main switch in your Mango so that it is automatically turned off when everything else is switched off. This way it also benefits from the fuse already fitted in the circuit to prevent the risk of fire. However, older Mangos didn't have a main switch. In this case you have to either fit to, say, the interior light switch, or directly to the battery. If you connect directly to the battery you must have a fuse in the circuit for safety. An inline car fuse holder fitted with a 3 A fuse will suffice.

For my own Mango I also designed a charging circuit to recharge the battery from solar power (perhaps I'll add that design to this web page at a later date. In this case you will have to do some soldering), and for Sinner I designed another similar circuit to charge the battery from a dynamo. The USB outlets make more sense if you have a way of charging the battery. However, they are also useful for running small gadgets which have a lower capacity battery than that of the Mango. MP3 players, for instance.

For those who might be interested, I took one of these apart and photographed the internals. It uses a switched mode power supply.

Adding a trailer hook

I added a trailer hook to my Mango so that I could use it to pull outside items. The Mango slows down a lot with a trailer because while the velomobile remains aerodynamic, the trailer certainly is not. However, while I lose much of the speed advantage of a velomobile when towing a trailer, I still get to stay warm and dry

Required parts: The L shaped and flat aluminium parts are both 50 mm wide x 5 mm thick aluminium. The width of the aluminium
spreads the load on the fibreglass body and avoids damage. Don't replace with a small washer. My trailer uses the Chariot hitch
on the left, but this should work with any trailer hitch which mounts on the left side of the rear wheel.
All parts assembled. The Mango body is sandwiched
between the aluminium parts
Another view of parts assembled

Two holes have to be drilled in the body, but they're on the
underside where they are not easily seen. If the hitch
is removed, just two holes remain, easily covered with tape
I use a Chariot hitch. It would have been easier for me
if I had made the vertical part longer.

I pull a trailer quite often to collect stock:

We have lots of other useful things, but we don't sell these hitches in our webshop. I have only made one of them for my own use, which is shown in these photos and which I still use. It works very well for me and I think if you make one the same way for yourself then it will work just as well for you. However, if you choose to do this, you do so at your own risk.

Changing the bell

In many countries, a bell is compulsory equipment on a bicycle. Even where it is not compulsory, it's useful as both a warning device and just to politely let people know that you will pass them.

The bell in the Mango (and other velomobiles) is inside the shell. This means that the bell isn't as loud to other riders as it would be on a normal bike. The bell fitted as standard is in any case not particularly loud in the first place.

Usually this isn't a problem, but occasionally I've found myself stuck behind slow elderly cyclists who clearly can't hear my bell at all, or teenagers listening to headphones who can't hear the bell because it's not loud enough.

Back in 2010 I tested bicycle bells to find out which was the loudest. The winner by some margin was the Widek 80 mm Ding Dong bell. It also made easily the most pleasant sound as you can hear from this sample:

Drilling a hole

Replacing the bell is a very easy job to do.

First drill a hole in the new bell in the part normally pressed by the thumb. This is to accommodate the string which is used to operate the bell inside the Mango.

Turn the Mango onto its side so that you can access the bell through the foot holes. Un-tie the string used to operate the original bell and remove the bell by undoing the bolts which keep it in place.

Install the new bell in place of the old, passing the string through the hole that you drilled earlier. Make a good large knot so that the string can't be pulled out of the bell. It's important to mount the bell as low as possible on the post.



Fakes abound, mostly with rather a less pleasant tone, and usually quieter. Genuine Widek Ding Dong bells are available at the DutchBikeBits webshop.

Where to find the Mango users / service manual

While working at Sinner, I translated the Mango manual to English and updated it to cover the more recent models. Unfortunately, Sinner rearranged their website in such a way that it isn't possible to find the manual any more. However, I have it and you can download it free of charge from here.

Where to buy parts and accessories

Our webshop,, has a special section with some of our favourite parts for recumbents and velomobiles, including tyres and lights.

This is Part Three. Go back to Part One or Part Two

For details of our other bikes, tour stories etc. return to my bicycles index.