Feet Forwards Motorcycle

I have had a full motorcycle license ever since I was 18 years old, and have ridden all sorts of unlikely machines under all sorts of equally unlikely circumstances ever since. This project was partly inspired by Julian Bond's website and by hunting around there you can find out much more about this type of single tracked vehicle. My desire was to try one of these things, and as the only commercial source is the Peraves Ecomobile which retail secondhand at 40,000 Euro (£25,000) which is way too much for a second hand bike unless it's the very Ducatti Mike Hailwood won on (the Ecomobile is well designed and built though). The only option was to build my own. Below are photographs of the build (photography by Andrew Barlow, Simon Mattews, and the author).


Taken in my father's workshop just after extending the frame. Here I was at the 'What do I do now' stage.
This is the clearest picture of the frame extension I have. Because Honda went for some quite elaborate swing arm bearing housings on the VF750FD I had to cut these out, then sandwich them between two 'sides' made of 1.5mm sheet. The bar across the back is there just to give location. The box in the middle was going to have been a battery and wiring box, but has since been removed and replaced by the fuel tank. After this photograph was taken the box was made stiffer in the lateral dimension by using more 1.5mm sheet in two triangular sections across the top. Needless to say the whole thing was in a jig at the time.
This is what it looked like in November 1998. Frame painted, roll cages both front and rear, suspension fitted, steering working. Everything but the wiring and seat to make a rolling chassis.
Same thing but rear three-quarter view. Notice how rear suspension has it's top mounting boxed in.
The first of the plastic bits. I used a GRP GSX750WT racing fairing (cheap) to base the front bit of the fairing on. I chopped it about and attached the bits to the bike. Then filled the gaps with ridged expanded polyurethane foam sheet (2" thick) (REPS) and glued it all together with polyurethane foam intended for home DIYer's to bodge their walls with.
This is the lower half of the same frontal fairing. It looks pretty unappetizing here. You can see where corrugated cardboard has been used to make ducting and other features on the fairing.
Exactly the same process for the rear bodywork, only no GRP precursor to base the shape on. In this instance the steel roll cage is actually going to become part of the bodywork.
A little more of the process. Here the inside has a layer of chopped mat on the inside. This holds it all together whilst you can then shape the outside to whatever you want.
A little later in the rear bodyworks gestation. The outside has been shaped and has a single layer of mat on it.
All the major bodywork components are now attached 'dry' to the rolling chassis, and the bike is substantially complete. But there is still a long way to go.
Plug for the front mudguard. First start with a mudguard, then add REPS and fill in the gaps with squirty foam. This will then be shaped, glassed over, a finish applied to the surface. Then a mold is taken (three part in this case), and the final mudguard is a casting from the mold.
Same process with the rear mudguard as for the front. This photograph was taken just before a finishing layer was applied to the plug's surface.
The completed machine minus the front bodywork. All the wiring, battery, and steering mechanism can be seen here.
Complete bike front view. The headlamp is from M&P and is listed as their streetfighter II lamp. The lamp units themselves are mounted in a scratch built aluminium housing retaining them behind the fairing, which just has holes cut into it to let the beams out. The front indicators are position lights from a lorry's trailer.
Complete rear three-quarter view. The rear lights are from a Peugeot 205, the silencers are no-name slip ons from AP.
Complete machine front three-quarter. The mirrors are Kawasaki GPZ replica from M&P and work really well.
Complete bike full on LHS.
Complete bike full on RHS.
Seating area showing Willans harness. This was a four point designed for Caterham 7s, a five point of the same style would be more suitable.

Specifications:

Riding Impressions:

VF750FD engine is OK, lots of power, a bit thirsty (approx 40mpg), but smooth and reliable. Horrible to work on. It has an additional oil feed to the top end, and the cams are new by the previous owner. It has a little pitting on barrel No 2, which we believe was caused by a high nitrate fuel (USA) combusting to nitric acid.

The brakes were worrying at first because they feel spongy. On the road they're fine. The steering is good, but there is a resonance at 30 mph which still leads to violent tank slappers. This only happens occasionally and can be accelerated through. I shall fit a steering damper. The whole plot feels fine at speed, but is tricky at very slow speeds.

Development in the short term will consist of fitting a screen, widening the rear cage, and fitting a steering damper. Longer term I shall fit a jockey wheel to the chain to stop it slamming about so much. I shall also re-finish the bodywork for aesthetic reasons, and re-pad the seat for comfort.

After two years riding it I have fitted the screen, and took it of almost immediately as I didn't design it properly and you got a lot of buffeting around it. I still haven't fitted a steering damper as they cost a lot of money, and have now grown used accelerating out of the steering wobbles, so they no longer worry me. The rear cage has been widened, and is a lot more comfortable as a result, but were I to start again I would make the seating area lots wider to allow a certain amount of movement from the pilot.

Handling is good in a straight line, but dodgy around bends. This is because the whole machine is too heavy, and the frame isn't stiff enough. Anyone starting a machine like this should thinking about minimising weight from the outset, and all the time (not using mid 1980's sports bike engines would be a good start). On the motorway the bike is the best I have ever ridden. It's stability is phenomenal, and for me it is reasonably comfortable. In sidewinds it is utterly stable even when other vehicles are having problems. The downside is that as soon as you stop the body-work which was making for stability at speed becomes a sail, so again low speed handling is compromised.

I used a very precisely machined clamp to attach the control bars to the dummy steering stem - do not to this! No matter how strong and well machined you make the device it will not work correctly, and will slip in day to day use. Do not try to get around the problem with some sort of sheer pin through the stem and boss - you only cause distortion which then makes the stem impossible to get out from the hole in the boss. The only way to engineer these things is to use splines. Get an old car and reuse the mechanism from that.

Surprisingly the chain and it's 2' extension have given no problems whatsoever except the odd clatter when you go over a bump.

Costs:

Donor bike purchased May 1997, completed bike MOT'd May 1999. I have receipts for 2377:51 (more detail below), but the real cost was probably around 3000 pounds.

Source Items Cost (£)
Racing Composites Fairing 170.00
David Silver Spares Carb rubbers etc 29.04
David Silver Spares Brake spares 92.88
David Silver Spares Head gasket 96.49
Crossley Bike Breakers CDI boxes 60.00
BMS Consumables 14.04
BMS Consumables 8.56
FWB Engineering (taps etc) 83.37
FWB (misc) 2.16
FWB Oil pipe 10.45
Fenner Chain 34.78
Machine Mart Tools 56.70
Machine Mart Tools 20.97
Machine Mart Tools 70.44
Machine Mart Tools 38.51
J.K.Hirst Battery 38.50
AP Motorcycles Disk and silencers 142.00
AP Motorcycles Donor bike 790.00
Europa Hoses 145.00
Europa Hoses 3.00
Europa Indicators 24.84
Europa Heat shield 22.58
Europa Seatbelt 56.99
Vehicle Wiring Products Wires 39.55
Vehicle Wiring Products Wires 134.84
Screwfix Direct Tools 47.03
Screwfix Direct Tools 47.80
M&P Levers 69.40
M&P Tools 73.50
M&P Air filter and other bits117.25
Farrant's Aluminium polishing 24.00
Motivation Seat 64.62
Hopkinsons Tools 3.21
Wicks Consumables 2.58
Wicks Consumables 16.48
Midland GRP Glassfibre 125.50
Midland GRP Glassfibre 167.44
The costings above include only those items for which I can find a receipt. I estimate that there is probably another seven hundred pounds spent for which I cannot account. The items above only reflect the major item on the receipt: I didn't in fact spend one hundered and seventeen pounds on an air filter, it was an air filter plus another load of stuff.

Major Suppliers: