British
Human
Power
Club

 

4 Week Fairing

Rate this Content 25 Votes
How it came to be and construction

I still remember the very first BHPC race I ever saw; the date was 31st august 2002, the location was Curbrough, I had not travelled to see the HPV race, rather my dad was racing the DF race on the same day. I did not even know the HPV race was happening, this was the day which changed my life, for the better as previously I was fairly inactive and spent a lot of time playing computer games. Of all the bikes I saw on that day it was the fully faired ones which I was most taken by.

In the following months of spending hundreds of hours on the internet I learnt that fully faired two-wheel bikes were only really made for racing and there were several aspects which made them impractical for everyday use thus I let the idea of a fully faired bike slip and started looking at more regular unfaired recumbent bikes and trikes.

In late 2005 at a race at Lincoln Ian C let me try out his allewader velomobile, this was the first time I rode anything with a full fairing and I know I wanted one in my future. Being multitrack also meant it would be practical for everyday use.

In late 2006 I built my first full fairing for a Trice S trike from correx, this stood upto about 6 months of winter commuting until I got the Quest, the Trice with correx fairing was later sold to a friend. The Trice fairing was surprisingly quick for something made in about 10 weeks from corriboard, about 3 Mph over the unfaired trike from around 16 to 19mph typical speed and only about 5-10% slower than the Quest.

At Castle Combe this year, after a request on the forum gNick kindly allowed me to have a go in his faired bike, the wooden fish on wheels despite the possibility of it getting crashed. I had not asked before now due to the chance of crashing and destroying someone’s pride and joy. I spent about 15 mins riding it, I got used to it fairly quickly (and I managed not to crash it). I had to stop though as I had a train to catch (and severe tailbone discomfort). I know a fully faired two-wheeled bike was in my future. At this time I was busy in the process of upgrading my lighting system in the Quest in time for Cyclevision, removing the large, somewhat ugly turn signals for more elegant Luxeon LED based signals as fitted as standard on newer Quests. After Cyclevision I got to try the fish again at Lancaster for a short period after the race. On the way home from Preston I knew I wanted a fully faired bike and I wanted one quick. Due to my success with the velomobile correx was the obvious choice for the fairing so the next day 4 sheets of correx were ordered and I started sketching designs for a fairing for the Fujin. I also revisited several websites detailing correx fairings and stumbled upon the Plastic Maggot. I set the Fujin up on the turbo trainer in the garage to allow me to measure myself and work out the clearances needed for my body and pedal stroke. The important things to measure are shoulder width as this will usually define the widest point of the bike. Also you need to measure the height of your knees at the highest point of the pedal stroke and also your toes. Another important measurement is the width of the “pedalbox”, the distance between the outsides of your shoes when clipped into the pedals. I decided on a design consisting of a tailbox which I could use as a tailbox by itself. The tailbox has enough space for a day load, commuting and perhaps light (credit card) touring. The front fairing is hinged on a bracket fitted to the boom and swings forward for access. The head bubble is attached with Velcro. This design unlike my previous fairing designs is pure correx, it has no in-built metal framing. The tailbox simply fits over the standard pannier rack and is fixed in place with two bolts. I used similar construction techniques to my previous fairings; the correx was glued together using a hot glue gun. It is very important that the glue is very hot and is applied quickly for a good join, I used a powerful 500watt gun which gives good results and generally pressed the parts together within 5 seconds of applying the glue. When gluing a long seam which means joining about 20cm at a time. Sanding the correx with 60 grit sandpaper also results in a stronger join.

Choice of glue sticks is also important, the general purpose sticks from screwfix are the best I have found so far and are cheap. Some other sticks I tried were too hard thus the joints were brittle.

The first part of the fairing I made was the main bulkhead which would sit at the widest point of the fairing just behind my shoulders. This took quite a bit of time to make as it was very important I got the size correct as this would basically define the overall profile of the fairing and would be very hard to change later. I then took another piece of correx and bent it over the top of the rear rack to form the wheelarch and also the floor of the luggage compartment in the tailbox, this was glued to the main bulkhead. The floor of the luggage compartment was shaped to the profile of the tailbox thus I could now bend the two main side panels of the tailbox into shape and glue them in place. The top and bottom of the tailbox were made by cutting panels to approximately the correct shape and then offering them upto the tailbox and attaching them with duct tape, I could now draw a line with a pencil where the new part met the parts already attached and trim the new part to the exact size before gluing it into place.

The front fairing began with a bracket which is mounted to the underside of the boom with zip ties, onto this bracket is attached a main “spine” with a hinge to allow it to tip forward for access. The hinge is made from 3 pieces of 40mm waste pipe with a piece of 32mm though the middle to act as a hinge pin, the pin can be removed to detach the front fairing. The spine is made from two pieces of correx cut to the side profile of the fairing making sure that my feet would clear the fairing but without leaving any unnecessary space. The two pieces are spaced apart by about 50mm with several spacer pieces thus forming a box section like construction with space for a vent channel.

Next I created several temporary cardboard bulkheads to get the shape of the front fairing right and then installed the two main side-panels in place The cardboard bulkheads were then removed. The top and bottom panels were added in the same way as for the tailbox.

The nosecone is made from several layers of leftover polystyrene insulation board which I laminated together with double sided tape and then quickly carved to shape with a hacksaw and 60 grit sandpaper (very messy). I then wrapped the whole thing in electrical tape (this was done at about 10pm the day before Darly Moor).

The front fairing is held in place with two spring-loaded latches which latch automatically when the fairing is closed and are released using a handle located just forward of the handlebars. 22lbs fishing line was used to connect the latches to the handle though several zip tie bases. A recessed outside handle will be added later to allow the fairing to be opened when the head section is in place otherwise I’d be locked out if I was to close it. The bomb bay doors are also operated using fishing line though zip tie bases. A small correx tag is located on the side of the fairing and is pulled back and stuck in place with Velcro to close the bomb doors. The bomb bay doors are hinged with heavy duty electrical tape (AKA lane marking tape).

The windscreen is made from 1mm PETG plastic, I decided to make it using a flat sheet rather than blowing a bubble so I can replace it easily if it gets scratched, I can also tint it by sticking film on it to reduce the “greenhouse” effect. The screen is fixed using Velcro so I can remove it for limited street riding.

Fresh air is provided by a vent in the nose, the technical term for this is a stagnation point air intake. A piece of 50mm waste pipe with a 45 degree elbow passes though the polystyrene nosecone and is joined to the main box section spine which runs along the top of the fairing and ends just before the handlebars. On a short test ride up and down the street it seemed fairly effective but I have yet to race it with the top on.

4 week fairing Technical specs:

Length: 2650mm (104")
Width: 460mm (18")
Height from ground: 1110mm (43.7")
Height of fairing: 860mm (34")
Ground clearence: 250mm (10")
Weight: 34lbs (15.5kg) (est)
Wheel sizes: 35-406 front, 28-559 rear
gears: 27, 27"-105"

Matirials used:

Correx sheet, 4mm white 3 sheets (8’x4’).
1mm PETG clear for windscreen
Polystyrene insulation board
Electrical tape (regular 19mm and heavy duty 50mm)
22lbs fishing line
Zip tie bases
Elastic bands
Glue sticks
Velcro
Zip ties
A few nuts and bolts (A2-70 stainless)
50mm waste pipe and 45 degree elbow
40mm and 32mm waste pipe (for hinge)

cost

Total cost: about £75
Total time: about 4 weeks/80 hours.
 

Pictures




Video