Greenspeed Magnum SD Yellow - With Extras

C$5,310.00

~~C$5,900.00~~ Excl. tax

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Available for Purchase Online (Call or text 403-748-3176 for Bentley Store Availability)

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Product description

Magnum SD/XL Overview

Comfort & Lumbar Support

One of the secrets of the Magnum’s superior ride is the seat. While it may not look fancy, one ride is all you need to experience GreenSpeed comfort. Firstly, the seat was designed by a chiropractor, so that it has both proper lumbar and shoulder support. Then the seat mesh is laced to the frame by shock cord, so not only does the seat conform to your back, it also provides “virtual suspension” to insulate you from road shock. People are like car engines in that they are only about 33% efficient, thus if you are putting out about 100 watts in power, your body is radiating 200 watts of heat which has to be dissipated. Thus, the seat is made of an open mesh outdoor furniture material, to provide ventilation and cooling to the back.

To further enhance the ride, the Magnum uses the 2 inch wide Schwalbe Big Apple balloon tires. These tyres are designed to be run at any pressure from 35 to 70 psi on an ordinary bike. However, as the wheel loading is much less on GreenSpeed trikes, due to the even weight distribution, these tyres may be safely run as low as 20 psi, to give soft ride without much increase in rolling resistance. And while most aluminium bikes have a harsh ride, the Magnum prototypes were made in Cro Mo steel, and then every frame tube was translated by engineers to give the same stiffness in aluminium. Thus the 7005 aluminium Magnum frame has exactly the same ride stiffness the original Cro Mo prototype, one of which was tested in the Himalayas. Then the wider seat of the XL further enhances the comfort brought about by the careful design of the seat, tires, and frame.

GS Crossover Steering

Many recumbent trikes have “direct” (tiller type) steering, where for cheapness, the handle bars are clamped directly onto the kingpins, without any intermediate linkage, and bars have to be moved in the opposite direction to which you are going, with the weaker muscles of your arms. Whereas the GreenSpeed “Crossover” steering was invented by GreenSpeed to provide control with your bicep muscles, thus the steering is much easier and more intuitive to use. Furthermore, unlike other types of “indirect” trike steering, the GS Crossover steering provides superior Ackermann compensation, and a smaller turning circle, due to the fact that the steering rods cross over from one side to the other.

GreenSpeed as well as other forward thinking human powered vehicle companies have discovered that the rolling resistance of bicycle tyres does not increase until a camber angle of 10 degrees is reached, thus to improve stability without making the trike wider, to counteract tyre distortion while cornering, and to reduce rolling resistance in the turns, the Magnum front wheels have 5 degrees of negative camber. Plus on tight turns the steering geometry changes the camber of the inside wheel from negative to positive, again to reduce rolling resistance and tire scrub in the turns. Plus by swapping the tires from side to side ½ way through their life, more life can be obtained than if they were ran vertically.

Unlike a bike, the front wheels of a trike are offset some distance from the centre line of the machine. Thus, applying one front wheel brake, as when hand signalling for a turn, while braking, will tend to steer the trike in that direction. So, to compensate for this, the Magnum has Negative Scrub Radius steering geometry, whereby the brake reaction steers the trike in the opposite direction to which the braked wheel is pulling it. This happens so subtly that all the rider notices is that the trike continues in a straight line, when only one front brake is used. However, for emergency braking both brakes should be used, as this will double the braking power.

Strong Folding Frames

Unlike steel, the welds in aluminium are not as strong as the parent metal, thus the frames of the Magnum XL and SD have been designed to eliminate butt welds, and are stronger than the earlier round tube Magnums. Plus all GreenSpeed frames are now made from 7005 aluminium tubing, which is stronger than the more commonly used 6061 aluminium tubing.

With every stroke of the pedals the boom of a trike is deflected downwards and the main tube is deflected upwards, under the seat. This wastes the rider’s energy. So, the main tube is made from rectangular section tubing which resists bending 30% better than the round tubing. Thus the trike is more efficient and you are rewarded with every stroke of the pedals. Likewise the use of rectangular tubing for the crank extension increases the stiffness of this member by 69%.

Use of the curved cross member both enables rider to get their legs closer the seat for easier entry and exit, plus it eliminates the butt weld in this member.

Like the previous Magnums, the XL and SD have seat adjustable for both height and recline with quick release levers, which also allow the seat to be quickly and easily removed so that the frame can be folded for storage or transport.

GreenSpeed Gearing

The Magnum comes as standard with a nine speed 11/34 cassette and a 52/42/30 crankset, giving a combination of 27 speeds and gear range from 18 to 95 inches.

Drum Brakes & Strong Wheels

Many trikes use disc brakes, blindly following the trend in cars. However, the weight of a trike is less than a tenth of the weight of car, and disc brakes have a number of issues - adjustment, maintenance, squealing, and making it difficult to remove the wheels. Whereas the 90 mm drum brakes used on the Magnum are more powerful than some disc brakes, especially after they are broken-in, only have one easy cable adjustment, have shoes which are practically everlasting, are quiet, and enable push button quick release of the wheels!

The wheels themselves have double walled eyeleted rims, which are built with 36 stainless steel spokes. Being only 20” in diameter, these wheels are both stronger and lighter than the 26” wheels used on mountain bikes. Plus as the rear wheel is 20” it can be closer to the seat, giving better traction, and making the whole trike lighter and more compact than if a 26” rear wheel was used. Plus, contrary to popular belief, testing has shown that the smaller wheels have lower rolling resistance, due to a rounder contact patch with the road.

	The SD will suit riders with an x-seam from 40 to 50 inches or about 5’ 3” to 6’ 7” in height
Extras	Loaded with Head Rest, GS Rear Rack, GS Accessory Mount c/w clamp
Frame	7005 Aluminium Alloy, with center fold.
Frame Size	SD
Width	34” – 86 cm
Length	66 to 76” – 168 to 193 cm *
Height	30 to 35” – 76 to 89 cm
Seat Height	14 to 18” – 35 to 45 cm
Seat Angle	30 to 48 degrees
Crank Height	14 to 15” – 35 to 39 cm
X-seam range	40 to 50” – 102 to 127 cm **
Ground Clearance	6.5” – 16 cm
Turning Circle	14 feet – 4.0 metre
Track Width	31.5” – 80 cm
Wheelbase	41.3” – 105 cm
Front Wheels	20” Double wall alloy rims with eyelets & 36 stainless steel spokes with push button quick release.
Rear Wheels	20” Double wall alloy rim with eyelets & 36 stainless steel spokes with standard quick release.
Tires	20 x 2.0” Schwalbe Big Apple, 35 to 70 psi

Gears	27 speed
Cranks	Shun SS-ZO-300 52/42/30 x 165 mm
Cassette	9 speed 11/34
Front Derailleur	Micro Shift
Rear Derailleur	Shimano Deore
Chain	YBN S9
Shifters	Shimano Dura Ace 9 speed Bar End
Gear Range	18 to 95” – 528%
Brakes	Sturmey Archer 90 mm drums
Standard Equipment	Rear mudguard, safety flag

Rider weight Limit	400lbs – 180 kg
Luggage Weight Limit	88lbs – 40 kg
Trike Weight	42 lbs – 19kg
Boxed Size	33 x 29 x 18" - 83 x 73 x 47cm
Frame Colour	Yellow