Finnish version

43 286 km  with the first actual Prototype

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Last uppdate 2007-01-12

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The assembly of the Prototype 1

• MIG-welded Aluminum frame, tubes of Tibnor-Aluma EN6063-T6, sizes 18x100x2, 40x40x2 and round 22x1,5 mm; plates 3...10 mm; no heat treatment, so the strength is between 80 and 120 N/mm² (the original profiles over 200 N/mm²)
• the driving front wheel 20" (406 mm), Shimano Nexus 7-Speed hub with Roller Brake
• Magura Raceline as the second (more effective) brake in front wheel
• SKF bottom bracket and Shimano 105 cranks (length 170 mm), two front rings (52/42), Shimano STX front changer and Sachs chain (normal length minus about 100 mm)
• a home made chain tightener (part of a Shimano SIS rear changer)
• two back wheels 26" (559 mm) without brake, wheel chair hubs (axle 12 mm); wheel gauge 870 mm (34")
• the back axle is moveable
• the tilt of rear wheels about 4 degrees
• front tyre Schwalbe Marathon Plus 48-406 and two raer tyres, Schwalbe Marathon Plus 48-559; not the best on sand roads but can resist punctures better than Big Apples that I used before
• mudgard in front wheel, PVC-sheets in rear wheels (now only on outer sides) to redure air drag and to make the trike more visible
• the rear axle can be moved, making 900...1200 mm (35"...47") wheelbase; with big load or in winter the bigger wheelbase gives more load on the driving front wheel; the normal (and best) wheelbase is 1000...1050 mm (40"...42")
• moveable seat, made of aluminium tubes 22 mm, width 400 mm (16"), rigid back rest, moveable head rest, covered with yellow Greenspeed mesh
• seat height about 300 mm (12")
• height of the bottom bracket 425 mm (16.5")
• road clearance about 80 mm (3")
• the lights, 12V/7Ah battery (2 Ah in summer, 7 Ah in winter), halogen lamp in front (5 W); LED back light, reflectors, reflecting tyres, flag, computer etc.; the mirror is on the helmet
• big trunk under and behind the seat
• length 1950 mm (77"), the biggest width 900 mm (35.5"), height 750 mm (30", head rest down) and 1060 mm (42", head rest up)
• turning radius 1.75 m
• weight about 24 kg without battery (frame and seat about 10 kg, bicycle parts about 14 kg -- Shimano Nexus 7Speed is quite heavy).

Driving characteristics

• Easy to drive because of leg steering; hands are used only to stabilize the steering; in speeds under 30 km/h (18 M/h) driving is safe without hands
• The front wheel inclines when turning and the center of gravity of legs is moving towars inner curve making the trike more stable and saving space compared with tadpole trikes
• An steering damper (Tourmax) is used to stabilize the steering and to calm the driving. I think, some kind of steering damper should be used in all trikes
• Without leaning the body it is possible to drive tight corners 20...25 km/h and curves with big radius over 30 km/h
• Two efective brakes are in the middle line of the trike, making stopping safe and straight
• The gear length of 1,9...6,9 m/pedal cycle is enough for flat country but not for extra hilly roads; Rohloff Speedhub 500/14 could be better.
• Cornering is much safer than with the Test Prototype because of the lower seat height and the bigger wheel gauge
• The small road clearance (n. 80 mm) is enough on all bicycle roads and in all normal situations
• Driving speed uphill is a bit lower than with uppright bicycle. 7-speed gear plus two front rings (52/42) are not enough in long hills. Short hills can be driven with speed, so that it is not necessary to strain. Pedal locks help much and make driving more comfortable.

Other characteristics

• Bright colors, plastic PVC-disks on back wheels and flag make the trike more visible in the traffic
• The trike can be stored and maintained in vertical postition. All wheels go around freely and claening is easy. Less than 1 square metre is needed for storage
• The trunk is big enough for camping equipment and groceries (look at the photo).

Reparations

Nearly all the parts have been changed duaring the 42.000 km and 8 years. Only frame, seat, bottom bracket, cranks and Shimano Roll Brake are left from the original Protohippus 1. Everything else I have changed because of fatique, failure or to get better quality parts.

Further development

After Protohippus1 I designed and built Hipparion Protohippus 2, which is lighter and smaller. It was ready in June 2001. My wife and doughter have tramped it only about 1000 km, so I don't know very well if the construction is as durable as Protohippus 1.

Protohippus 2 is on its own page (text in English).

Differences between tadpole trike and Hipparion delta trike

• There is more room on the trunk. CG (center of gravity) is low (bottom 200 mm above the ground).
• Hipparion takes less space in corners than tadpoles because the front part tilts and feet go first to the right direction. Pedestrians and other people see better where I am turning. Turning circle is small, about 3.5 m (radius 1.75 m).
• Steering rod does not disturb driving, the tube does not hit knees.
• The steering is stable. There is no "snaking". Hitting stones with the front wheel does not change the direction. But there MUST be a steering damper to make fast driving stable.
• Front wheel drive is better in winter than back wheel drive. Front wheel driven trike goes better through snow and turns better to the right direction.
• All technics are in the front wheel; chain is short; only two brakes are needed.
• Braking is effective and does not change the driving direction. Full braking in corners is possible, if road is good (not slippery).
Two brakes do not need much finger force when used together (Magura Race Line hydraulic brake and Nexus Roll Brake).

Driving in winter

The weather in Helsinki is very changeable at wintertime on the South coast. Many times the paths are full of dirty water and oily wet snow. In the afternoon the snow is freezinf and getting hard and very uneven. Duaring the winter the town adds more and more gravel on the road. The gravel is cleaned in March and April, but not all.

The lowest temperature duaring six seven years has been –23°C, not vey bad. Shimano Nexus SevenSpeed gear is little lazy in cold temperatures (frozen wire). I shortened the gear wire nearly 1 m (now about 0,5 m) and works better. The steering damper does not stand cold. It's letting air in.

Some more photos of Hipparion

 
              


Interview in Gotlands Allehanda in 6th July 2000. About 30 kg on the trunk

How it works? Animaation 1.5 MB (Hippa.avi) shows, how the leg steering works. A simple animation without the driver.

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