Trikes Mailing List & Recumbent Trike FAQs-(or the world as I see it)

The International Human Powered Vehicles Assn (IHPVA) has sponsored a mailing list specializing in recumbent trikes.

I am it's manager/owner and I recommend you subscribe! I'll make it easy for you, just decide which version you want. The digest version combines a group of messages into one message and sends it out about once a day or so.

trikes@ihpva.org is the list location

Recumbent Trike Design - the reader is referred to http://www.ihpva.org/faq for info on recumbents in general

Why a Recumbent design?

FASTER At 30 kph (19 mph) on a conventional bike, 80% of the rider's energy is wasted with air resistance. But with the riders legs horizontal and the seat laid back at a comfortable angle, air resistance is much less. The ergonomic seating position enables a more powerful pedal thrust, making you faster off the mark, as well as superior in top speed as well as less prone to side buffeting on three wheels. A fairing can make a real difference.

Tadpole- 2 wheels in front, 1 rear are the most prominent in commercial trike design. In general they are better at cornering, have simpler drivetrains, and are faster at stopping, but:

Delta - 2 wheels rear , 1 front are generally better loadhaulers, and are more agile at low speed, making them the design of choice for workbikes. They also can be linked front to rear to form composite "tandems".

Trike Stability and Safety- The stability of a vehicle with only three wheels compared to one with four is often a cause for concern and confusion. If you are free to put the center of gravity and the wheels wherever you want, you can always get stability, but a trike usually trades off some stability for practicality. Body english and/or riding skill with anticipation then are needed to keep the rider out of trouble in some situations. Briefly, if you have two wheels in front, and you put on the brakes, the weight goes onto the front wheels and you are going to have stability pretty close to a four wheeler. In almost any emergency, you can manage this. With the front brakes on hard, you can also swerve, and if you overdo it, you go into a straight (understeering) slide, not a roll. With one wheel in front, if you put most of the weight there by braking, you have got pretty much the stability of a kid's bike on narrow training wheels. Any attempt to turn with normal vigor, or even a road irregularity, could dump you. Any doubters are invited to look up the insurance rates for Harley trikes, check the law about ATVs, or gaze at the little metal skis on the front of the Cushman scooters, designed to make any roll turn into a straight skid. To get through hard braking safely, a delta needs most of its' weight low and to the rear, and if this is not possible, the length and width have to increase to give the same angles. A nice battery pack, or trailer hitch can weigh that back axle down nicely, as can appropriate cargo. In steady cornering, this rear weight bias will almost always produce oversteer at the limit. Sporty deltas can be ridden, and well, keeping the limitations within mind and trusting luck to not find one of the unsolveable situations. If we want a tall, narrow design, the stability for fast cornering can be boosted with the addition of a tilting mechanism. There is less reserve for wind gusts and inaccurate leaning, but this is not usually a problem, whereas fast, safe cornering is an energy-conservation issue. Tilters are subdivided into three types. Any of these methods will help either tadpole or delta, but the overall stability will be affected by braking just as it is in the upright types, or even more so if length does not keep pace with the rise in the center of gravity. Leaning also makes a trike quite a bit more comfortable on cambered road edges. The "free-leaners" are ridden, balanced and steered just like a bike, except for occasional use of the trike stability, at stops and, one hopes, when caught out by a crosswind gust in a narrow lane. The lean-steer type uses one control to both steer and lean, so it is either optimized for one particular speed, or has another control axis to set the mix of leaning and steering for any speed. The power leaners can use muscles (usually relaxed and free-leaning) or motors, and if the latter, they can be driver-controlled or robotic.

There are no absolutes in the type of trike design you employ, so it's "caveat emptor" or "buyer beware" - insist on a test ride. There are many ideas which prove these concepts wrong, Your Mileage Will Vary - here is a list of recumbent trike manufacturers: http://www.ihpva.org/SourceGuide/Vehicles/index.html#Recumbent Trikes and a group of do it yourselfers including free plans for a trike: http://www.ihpva.org/Builders/. Another excellent source of information is RCN ((http://www.RecumbentCyclistNews.com). you should be prepared to pay a little more for your extra wheel (less than an new auto, but more than a new mountain bike - these are mostly hand-built by devoted craftsman, and not turned out in a factory in Taiwan. If you do purchase a foreign made trike be prepared to 1) wait, 2) Currency Issues, 3) Shipping Costs, 4) Import Duties. Patience is the key word when dealing with any manufacturer - foreign or domestic.

 

MORE COMFORT the larger hammock-type seat used on many commercial trikes means no more sore bum syndrome on long rides. No more sore hands or aching wrists and shoulders either. The seat can be made of a strong, open weave material allowing ventilation and cooling for the back. It is also laced with elastic cord to insulate the rider from road shock. In fact, people who cannot ride conventional bikes because of back problems find they can ride these trikes easily. Another growing trend is to add mechanical suspension to the trike, either in front , more commonly in the rear, but there is the issue of added weight, complexity, and cost. Speaking of issues how about tire size? The tradeoffs are 3 similar tires (spares easier), smaller tires (16") larger rear tires

GREATER SAFETY Conventional racers ride head first. Vulnerable. Recumbents travel feet first, weight low and further back. This gives superior braking and eliminates the danger of going over the handlebars.Many High end recumbent trikes feature drum brakes which provide further braking superiority irrespective of wheel-rim or weather conditions. Braking performance is on a par with cars! Our tandem recumbent trike even has hydraulic brakes for added stopping power

Fluorescent colored frames and safety flags are used to enhance visibility. In fact, trike riders report that they get more respect from motorists than when on conventional bikes.

LESS EFFORT Lower air resistance means less effort at the same speed, and at 30 kph (19 mph), A Greenspeed recumbent requires only about 75% of the effort of a conventional bike. In addition, instead of the rider having to support his or her upper body weight on the handlebars, this weight is comfortably supported by the hammock-type seat. The energy you save on longer trips is quite remarkable.

Mark and wife Lizzie this summer in Fairbanks on road to Chena Hot Springs.

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