Introduction: HPV-QUADRICYCLE FOR TWO
When I was a boy, I dreamed about my bicycle, but never had one. During my childhood and early youth (fifties and early sixties), bicycles are rare in Belgrade, Serbia, old Yugoslavia - there were just a few around. I lived in center of city (quite decent part with a lot of embassies) and there were just a few of bicycles in near-by building that we named "American", because of their high standard of life (probably domestic people from state and party establishment)...
Later, many years I was saving for my bicycle (wonderful example in the main general store in center of the city). Every-time when I visited it - it was more and more expensive: from 9,000 dinars to 28,000 dinars. When I collected all that money - I realized that it is too small for me - that was some kind of sporting type, smaller a little than original adults bikes. The pain was that one fellow in our new neighborhood have one just the same as "mine"... It seems that I didn't understand well economy, finance and law of inflation?
When I was twenty, I got VELOSOLEX moped and later BENELLY scooter from my brother - and learned to ride two-wheeler: didn't know to ride bicycle very well before that. Many years after that I got from a friend one modified old and big bicycle but later gave it to another friend to make a replica of motorised bicycle with domestic KRUSIK engine...
In teenage years, HPV-quadricycle became my dream, when I saw some pictures and plans in older Russian magazine (they used such vehicles for regular transport (not just for fun or sport)... Many of them hadn't possibility to buy a car or motorcycle, especially in far away parts of country. Strange thing – now, I found a few of pictures and sketches from that old magazine – thanks to Internet!
As it will be seen later, my dreams are realised now!
NOTICE: English language isn't my native language, so please excuse me for rude style, simplicity of sentences and mistakes in writing...
P.S.: Attached are photos of my Benell micro-scooter, then Velosolex moped and finaly my big old bicycle...
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Step 1: Step 1: INTRODUCTION
After I arrived to Switzerland a few years ago, I noticed that Bern is occupied with thousands and thousands of bicycles – harder to find parking space for bicycle than for automobile. There is huge garage in center just for bicycles and it is always full. Everybody (kids, teenagers, parents with kids in trailers, seniors or both genders...) ride them entire year, including wither with snow. Drivers are quite tolerant toward them, respect them and take care in traffic. There are a lot of bicycles paths and lines in city and around (almost on all local roads). Many parts of town had general restriction of speed up to 30 km/hour ~ 18.6 MPH and there is large pedestrian zone in old town, allowed for bicycles...
Real paradise for for some multi-wheel pedal-powered vehicle for two seniors (now pensioners)? Shouldn't be safe on two-wheel bicycle, especially on some kind of tandem for two of us – and some three-wheelers that I saw, are too expensive for us. Therefore, I finally started planing, buying components and building my own quadricycle for two persons! It was planed and build just for relaxed cruising across and around Bern and further through wonderful countryside, more for a joy and light recreation, but some practical use too (free transport)...
I had garage for work, bought some tools, make a few variants – and now have finished simple and cheap HPV-quadricycle! After considering all possible variants of three-wheelers, I choose four-wheeler (quadricycle), because of stability and easier distribution of quite a heavy freight. Together we have almost 190 kilos ~ 419 pounds, which could be in the limits of such vehicle. Keeping original MTB wheels was another reason to have four of them.
P.S.: Attached are sketches of some old Russian velomobiles (USSR period)
Step 2: Step 2: FINALE REALIZATION
After a lot of dilemmas, I abounded idea of some classic velocar a'la Mochet - too complicated and expensive for the first project. When I check prices of components (one of the planed variants was to buy components and build my own chassis) - they should cost me twice as bicycles: around 1,100 $$$. So, my quadricycle is built simply by connecting two male MTB, without cutting frames and welding. They cost me around 550 $$$, which is cheap for Swiss, but in Belgrade I could have all that for less then 250 $$$.
Problem was that at beginning my wife had desire to pedal with me, so I started to make such arrangement. Later, she decide that she would prefer "rickshaw" style, so I change everything – the second variant with me pedaling at front and she seating at rear. Later, I built the third and final variant: me at rear and she at front!
Weight of final variant is 52 kilos ~ 115 pounds, which looks too high, but bicycles alone had weight of 2 x 18 kilos = 36 kilos ~ 80 pounds, which means that I add some 16 kilos ~ 35 pounds. That could be lighter, but I used what I could find and buy cheaply and install easily...
Distance between front and rear axle is 108 cm ~ 42.5” ( standard bicyles dimensions, without modifications) and distance between wheels (and frames) is 70 cm ~ 27.5”. That was a little crumpled dimensions for two of us, but at the end it was satisfying and good for bicycles paths and lines.
As could be seen, I am seating at rear and high, in similar position to ordinary bicycles and my wife has a place in front, as on some Asian rickshaw... There are some details to be finished: mudguards/fenders, canopy, signalisation, trunk at rear... But, that shall wait on our return from holiday in Belgrade, that will started in a few days.
Details shall be seen in following steps, the same as results of testing. There wasn't time and possibilities for more photos and videos. Maybe, they could be add later?
NOTICE: All this is the story about my realization of my dream and building my project – not a plan and advice for anybody to do the same or similar, in general or details. Any wheeled vehicle is moving thing ans so – it is dangerous thing that could make damage to property of driver, passenger or public and injure or kill driver, passenger or somebody from public. If somebody make something inspired by my article – all that is his/her responsibility, during building and driving – not mine! Build and drive safely, respect low and other persons.
P.S.: Attached are phOtos of finished quadricycle, the third and final version!
Step 3: Step 3: PREPARATION & PLANING
At the beginning, I defined some goals that could be good if achieved:
1- to have rides together with my wife (but solo, too) – at final version, pedaling just for me to avoid complication;
2 - to ride in some way of comfort (leisure position, easy step-in and step-out, wind/rain and sun protection);
3 – to avoid building complications: no cutting and modified bicycles frames, using knowledge and tools that I have and to please myself during building;
4 – to achieved safety factors, general and our specific: neither of as are experienced rider (good stability, precise and safe steering and braking, some protection from impacts of cars;
5 - to have interesting, and if it is possible, cute vehicle (not to be embarrassed during rides) – but without too complicated details or “perfect” finish – it would anyway looks as cheap and simple DIY project;
It was build by us – just for us! No needs to pleased other too much, or to make it adjustable... Never had intention to sell plans or possibility to make something similar in professional way, as possible small-business.
At the beginning, I made some simple sketches, just to check my ideas and possible realisation in a few variants. In meantime, I bought two MTB and took all their measures to check possibilities with a few variants (cutting or not the frames, make them longer and so on...). In the same time I took all our main body-measures, so to define ergonomic positions: seating, steering and pedaling. Result was decision to simply joined two ordinary MTB, with tandem-seat position between frames!
The first variant with both of us pedaling – was abounded because of too many mechanical complications and not easy designing proper seating positions in mentioned simple construction...
The second variant, with wooden module between bicycles frames, with me pedaling and steering in front and my wife seating at rear – was abounded before almost finished! It shown that my position isn't so good as I expected. IMPORTANT ADVICE: at the beginning of construction – make simple and cheap wooden-stick model in full size to check position for seating, steering and pedaling!
So, quadricycle was almost “destroyed”, just keeping some metal connecting components (modified) – and everything started from beginning. The end was the third and final variant that could be seen on many photos.
P.S.: Attached are photos of the first and the second variant!
Step 4: Step 4: BUILDING PROCESS
Used tools were simple: electric grinder and electric hand-drill, later welding apparatus (just for fixing new pedals) and various simple and cheap hand-tools. On the floor, I draw rectangular shape, for easier keeping straight base of quadricycle, with additional wooden sticks for help. I was working alone, so no help of “third hand”. Some claps and bung-cords were helpful. The same - new metal chairs that I planed to use after abounded central wooden module.
I used metal square frame from the second variant, modified/shortened and some other tubes, pipes, frames – that I found in hobby-house-garden centre BAUHAUSE. Going many times to shop to search and find something that is useful for next phase, being cheap and practical. All that could be seen on photos and I think that do not need sketches and detailed explanation. Everybody could find the same or different – but good for his use.
Front seat was combined of two aluminium garden chairs. My “saddle” is DIY, something bigger than usual and much softer. Need some better covering.
As all connecting construction consist of various metal parts (aluminium, chromed steel, galvanized steel, gray iron), I bought good base paint and covered everything, including bicycles frames. After that – red colour (for higher speed as my old friend liked to say)...
P.S.: Attached are photos from construction process!
Step 5: Step 5: DETAILS, Pedals
I decided to use simple crank-shaft DIY pedals, attached to front sprockets (screwing them at the place of removed original pedals). During the first testing, I discovered that screwing do not keep system well, no mater what I tried. So, I bought cheap welding apparatus (birthday present from my wife) and weld every joints, on my balcony. I think that photos are enough descriptive? Just to add: flat bars are aluminium 5 mm thick 50 mm wide strips. In the middle, there are two strips of plywood in sandwich of aluminium.
P.S.: Attached are photos with pedals: assambled, welded and instaled at quadricycle!
Step 6: Step 6: DETAILS, Steering
The main part of steering system are regular MTB front forks. They are connected with trapezoid at the axle-fixing points – so Ackermann principles is obtained.
Steering is by two handles taken and adapted from bicycles handlebars.
P.S.: Attached are photos of steering system.
Step 7: Step 7: DETAILS, Commands
Used are original rim-brakes... Commands are attached on mentioned steering arms and could be used in any combination: front or rear, left or right, or all of them when needed.
Rear derailleur is controlled by original controls on mentioned steering arms, one for each rear wheel. Therefore, both rear wheels are powered – but, that could be changed with removing right chain.
On original saddle-points are attached commands for front derailleur system, one for each front sprocket. As mentioned, both shall be used, but there is possibility to use just one is as described above.
P.S.: Everything could be seen well on attached photos.
Step 8: Step 8: DETAILS, Seats
As I wrote, front seat for my wife is made connecting two aluminium garden chairs. It is comfortable and give good support to body and feet, but it also fixed quite well front part of quadricycle. I think about putting some seat-belt for her.
Step 9: Step 9: CONCLUSIONS
Testing was done just by myself on quadricycle – my wife was busy with finishing work in our garden and preparation for great voyage to Belgrade.
Generally, I am satisfied with performances of quadricycle, even something could be better done next time.
My seating position is comfortable with excellent passive and active visibility. Driving comfort is good, without twisting and vibration of construction.
Steering is easy and precise. Turning circle isn't small as I would like, but it is quite adequate for city's streets – nor problems with corners.
Pedaling is easy in spite of heavy weight. I didn't measure top speed, but it is similar to other bicyclists on streets, except of top-form riders... I am not sure for hills – didn't try any of them. Anyway, they could be avoided as I do not have strict need to conquer any of them. Steeper streets could be avoided too. Most of the city and nearby countryside is almost flat. When I menage better to use derailleur system – I could try some hilly streets. I suppose that with two of us – I had to choose just flat streets and roads, to avoid snail-speeds.
Would I do something different next time? Probably – yes! After more testing, under full weight, I will see what is necessary to change (if any) on this one. In any case, I would try “electrification” of it adding some electric motor, maybe hybrid power and so on. The first to see acceptance of this one, by general public and authorities.
Our wish is to build next one, as was consider at the beginning – in a style of classic velocars, with side-by-side (sociable) seating and both of us pedaling – and, again to consider some electric motor to have less problems at hills, starts at traffic lights and to obtain speeds up to 20 MPH ~ 32 km/hour.
If somebody is pleased with my project – I would be happy, if somebody use it as inspiration to build one – I will be honored. If I got some prize – that would be good, but I could live without it, too. Positive and negative comments are welcomed, questions too. I am not sure could I answer on all that in time, because of problematic internet connection in our flat in Belgrade!