Greenspeed Magnum Trike

Many are considered, one is chosen



The good news is I own a Greenspeed Magnum 2012 model and use it almost daily, and so may be entitled to say something of interest. The bad news is I have not tried, much less owned, every bicycle or trike ever made. Having neither the storage warehouse nor the money to product test all offerings, I instead endeavor to consider the design of all products of human ingenuity. I've never ridden a penny-farthing, for example, but others have (or did) and their experience can be vicariously known, allowing preference to be given to the Safety Bicycle design.

Other forms of human-powered wheeled conveyance include roller skates/blades, scooters, skateboards, and various (as in many thousands of) designs based on the 16 inch to 36 inch bicycle wheel (unicycles) or wheels (bikes, trikes, velomobiles, everything else). It is the bicycle wheel that defines bicycle technology whether one, two, three, or more wheeled. “Bicycle” implies two, so “cycle” is more inclusive. Cycle wheels offer the most efficient means ever devised of transporting a person over a moderately smooth surface. Since my interests are more practical than sporting, vehicles using cycle wheels (cycle tech) get the nod and other alternatives will not be further considered.

Upright cycles involve sitting on a padded post. Been there, done that, and have ridden a recumbent bicycle for a number of years. Recumbent, sans sore-butt, wins. Aside from comfort, sitting on a post is problematic when not in an upright position. At speed, most energy goes into stirring the air, and even if hunched over the bars, frontal area is larger than when in a recumbent position. The earliest recumbents won the race (unfairly it seemed to all the upright cyclists), and so were banned. The issue the real bicyclists had was they lost, as no claim could be made that recumbents were unsafe or functioned poorly. Recumbents were banned from competition simply because they won.

There are touring, mountain, and racing unicycles, but no recumbent unicycles, and most are single speed sporting machines as distinct from practical. As confessed, my interests are on the functional side of cycle tech, so cross off unicycles. Like unicycles, bicycles are unstable at rest, and serious bicyclists scorn to carry the extra attached weight of a kickstand. Bicycles are practical for transporting an exposed human, are stable enough, and can follow a narrow path. They also lean into curves, can be ultralight, and they do 'keep it simple'. To keep a design light and minimalist, no weather protection is provided, which includes neglecting to shade the rider from the noonday sun. A walker or upright cyclist with a broad brimmed hat is afforded some protection, but a recumbent position, whether on the beach or on a bike, maximizes exposure. If some protective enclosure is to be considered, the inherent instability of a bicycle at low speed or at a stop becomes an issue. Two-wheeled velomobiles (streamliners) maximize performance, but the rider has a support crew to help get up to a stable speed and hold the velomobile upright at rest while the rider is extracted. Practical velomobiles use three or four wheels for stability at any speed.

If being an exposed recumbent human will never be a deal breaker, then keep it simple and go with a recumbent bicycle. If aerodynamic slipperiness or sun/weather protection is a reasonable consideration, a trike or quad becomes a stable platform to build upon. If straying from minimalism, if adding functionality is being considered, then consider that the adding of weigh soon exceeds even a fit human's capacity to power the vehicle effectively. Since many average (not very fit) humans can't effectively power even a minimalist bicycle, adding electric assist (and more weight) is needed. To untether an electric cycle from the plug, solar panels could be added and a stable multi-wheeled vehicle becomes more of a necessity. So four wheels are a possibility, and three wheels are enough. There are many trike designs to consider, few quad-cycles, and no compelling reason to go four or more wheels, so a no surprise end-point of "all cycles considered" is a trike.

There are many trike designs to consider. The designs come in two flavors: two wheels behind (delta trikes) or two wheels up front (tadpole trikes). Putting the steering wheel or wheels in back has been tried, but the consensus is that rear steering is problematic. In a delta design with front wheel steering, one or both rear wheels are powered. In the tadpole design, the one and only rear wheel is powered and both front wheels move to steer. The consensus experience is that if only one wheel is powered, the tadpole design works best. If a delta design is preferred, it would be for the increased traction on loose surface material that comes if two of the three wheels are powered. On pavement and firm off-pavement surfaces, one powered wheel is enough, so the tadpole design tends to win out over a two-wheeled drive delta design, but only slightly.

For practical use, off-pavement ability is important. If off-road use is important, as in following narrow deer trails, then a mountain bicycle is needed. If deer trails are best explored on foot, however, then only off-pavement ability is needed to explore the dirt roads that abound everywhere outside of wilderness areas. An ability to follow Jeep trails is uncommon among trikes and eliminates many designs from consideration. If touring by trike is to be an option, then load/weight carrying ability is needed and that eliminates other designs. Most recumbent trikes are ultralight high-speed offerings that appeal to the swift of wheel. For the more ploddingly practical who want a recumbent tadpole with load-carrying capacity yet, in so far as possible, who also want a well-made, high-performance trike, then there is the Greenspeed Magnum.

The Greenspeed Magnum can reasonably claim to have the most comfortable seat with "virtual suspension", to be the only off-pavement friendly trike, the only one with vertically adjustable seat height and variable degree of recumbency, and it is made to carry 480 lbs. of rider/stuff (most others having a 275 lb. limit). The frame is still reasonably light, being made of aluminum. And it folds, and the front wheels easily pop off for transport. Ian Sims, the designer, had to make many choices (design is a study in compromise). In this designer's view, he made all the right ones, so I just bit the bullet and bought one. Still seems like the right decision. There are other temptations, but overall the Magnum is a sensible choice as a foundation to build a solar touring trike. Bottom line: it is the only trike designed for the less than fit who most need to ride one. If you already are fit and pick a different offering, and want help from SolTech to turn it into a solar touring trike, you may have to talk me into buying what you bought, or come to Tucson, bring your trike, stay awhile, and we'll figure something out.

The only thing not to like is the price, although it is actually mid-priced and is argueably a good deal for what you pay for. The Greenspeed Magnum comes from Australia, is not mass produced, cannot be bought at Wal-Mart, and top-drawer comes at a price. If, after considering all cycle tech offerings, the Magnum is it, then buy one or study the design and try making your own (I decided not to, but have fun trying).

Okay, I did make a few tweaks, so I guess (for me) the apparently high price wasn't the only thing not to like. The gearing was too high. In my youth I had endurance. I could walk from one rim of the Grand Canyon to the other in one day, but I was never athletic, never fast or high energy. After getting hit by a truck and after months of immobility, I was decidedly on the unfit side when I started riding the Magnum (to help increase my activity level and go places). Although I used all three of the 52-42-30 chainrings, I stayed in the lower of the 9 to 32 rear gears. The Shimano/SR 9sp. 9/32 is modified from the stock 11/32 cassette to add the higher gears. Although with an e-motor, the high 52 to 9 gear ratio (124.7 gear inches) could be used, I wanted to be able to get around without the motor, which depends on having lower gearing.

A major advantage of a trike over bike is that trikes have no lower speed limit. They are stable at any speed and there are no gearing options that are too low. As I often ride on steep unpaved roads, I often run out of low gears while never using the highest gearing. So an 11-34 cassette gave a big boost in low gearing. I also replaced the 30t chainring with a 24t one for a 52-42-24 set of chainrings. The 24 to 34 low gear (15.5 gear inches) was about as satisfyingly low as gearing designed for two-wheelers can provide. The current model Magnum comes with the perfect (for me) 11-34 cassette, so I was likely not the only one who thought a 9-32 cassette was on the too high side.

I also decided that, even if I had a 1500 watt assist e-motor for hill climbing, that 15 mph (25 km/h) on the flats was a reasonable safe and sane maximum speed limit (compared to average human-only powered speeds, 10 to 15 mph should be considered high speed). While 15 mph is not the legal limit in America (except on multi-use bike paths), it is faster than most human-power vehicles can go who have average humans pedaling them and is fast enough. At 60 rpm my top pedal speed is now 15.8 mph (down from the stock athelte-friendly 19.3 mph). So a 52 to 11 ratio is perfect (102 gear inches). Low speed was 3.1 mph (30 to 32 or 20.2 gear inches), a fast walking speed too fast for many slopes in my area (1% slopes require 50 watts to climb at 3.1 mph, and as I was working on becoming fit enough to output 50 watts continuous, even a barely perceptible 1% slope was a deal breaker and truth be told many adults are less fit than I). With a 24 to 34 low gear ratio, 2.4 mph (3.8 km/h) became my low speed and my ability to climb moderate slopes was significantly improved—which is vastly more important than going a bit faster than too fast.

The first time I went out riding the Magnum a cold wind was blowing, and then the hail came, turning into rain. I added a Windwrap partial fairing a short time later. While speed is improved, weather protection was a bigger plus. In the summer (and in Tucson, Arizona, the oven-hot sun is not a recumbent rider's friend) the fairing nicely supports a shade cover. Of course a practical vehicle needs a rear rack. Although I have no use for a headrest, my wife, who sometimes rides the Magnum, judges a headrest to be essential (for napping at a stop?) as in the recumbent position some people's heads want to go back and need support. Fenders are another option, and with the front wheels to the side, fenders are optional, but at speed your arms will get wet. Still, to be singing in the rain, get fenders/mud flaps and a fairing, both of which can come off easily when not needed.