Magnum SD/XL Overview
The new 2017 Magnum trike builds on our very successful Magnum which was launched in 2012, and has been our best seller since then. The 2017 Magnum comes in two sizes, the SD which is the same size as the original Magnum, and the XL, which is the largest production trike in the world, built to accommodate riders up to 7 foot in height and weighing up to 450 lbs.
It retains the unique features of the earlier Magnum which made it so popular, the seat height and angle adjustment, plus the press-button quick release on the front wheels, plus the on road and off road capabilities. However, to strengthen the frame over the earlier Magnum, we are using a rectangular section main tube, 1st used on the Anura introduced in 2006, and recently on the GT20, introduced in 2016.
This tubing is both stronger and lighter than the round tubing used on the original Magnum, plus it allows quick and easy adjustment of the boom for leg length without having to realign the cranks each time, and positively prevents the cranks from twisting under sudden acceleration.
And rather than the “Ved” cross member of the early Magnums, the SD/XL cross member is curved like the GT20, to allow the riders to stand closer to the seat, for easier entry and exit.
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.
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. This will be adequate for most uses. However, some riders may wish to extend the gear range and there are an almost infinite number of ways of doing this, as these GreenSpeed Magnum Gear Tables in MS Excel Workbook format show. For people just wanting a lower gear, the 30t granny can be changed for 24 t ring, and for higher gears the 52 t ring can be changed for a 56t ring as used on the GT20 and Aero trikes. For people who want bullet proof internal gears, without the maintenance of derailleur gears, we recommend the 14 speed Rohloff, for which the Magnum has the special Rohloff OEM dropouts, and extra cable guides to take the twin gear cables of the Rohloff. We also have limited stocks the SRAM 3×8/9/10 DualDrive hub, and recommend the Nu Vinci N380 infinitely variable hub, which totally eliminates the steps, bumps and clunks in a normal gearing system. Plus, contrary what Rohloff might say, we have found that on our trikes, the Schumpf Mountain drive can be used with the Rohloff without any problems, due to having a smaller rear wheel, and less weight on the rear wheel than an ordinary bicycle. And for people who would like even MORE gears, we are now offering special crank extensions for the new Magnums to suit the Pinion gearbox which can provide 18, 12, 9 or 6 speed gears at the cranks! See Gear Tables.
The standard cranks fitted to the Magnum are 165 mm. This is shorter than the 170 or 175 mm standard used on most MTBs. However, for some unknown reason, shorter cranks seem to work better on recumbents, thus the fitting of 165s as standard equipment on the Magnum. Shorter people may find they are more comfortable with cranks which are shorter again, as explained on this website – http://www.nettally.com/palmk/crankset.html Thus in case of difficulty we can provide cranksets in 160 and 152 mm, and can also provide a shortening service for some cranks.
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.
Uses & Accessories
The Magnum is one of the most versatile trikes ever built. The original Magnum is in use by riders from as small as 100 lbs to as large as 400 lbs. And the Magnum XL will suit riders from 150 lbs to 450 lbs. The SD will suit riders with an x-seam from 40 to 50 inches or about 5’ 3” to 6’ 7” in height. The XL from 44 to 55 inches X-seam or from about 5’ 9” to 7’ 3” . It is equally at home doing a transcontinental tour, as it is commuting, popping down to the milk bar to pick up some bread, or just exercising and having fun outdoors. The optional, specially designed pannier rack has been hailed as one of the best available. Made from high strength aluminium alloy tubing, weighing less than ½ lb, but rated at 88 lbs, it withstood the standard vibration test for bicycle, of 100,000 cycles with a 40 kg load instead of the standard 25kg load. See test report.
Another popular accessory is the accessory posts. These posts clamp to the kingpins and hold mirrors, grab handles to ease entry and exit, accessory mounts for computer, GPS etc., plus front fenders for wet climates. To enable quick and easy adjustment for leg length, the Chain Gobbler is available. See accessory page or for more information contact GreenSpeed USA or GreenSpeed Australia.
GreenSpeed – Changing Lives
“My Name is Peter James, a 62 year old disabled man diagnosed in Oct 1995 with Multiple Sclerosis. MS is an insidious incurable autoimmune disease affecting the central nerve system. With a rapid decline in mobility and associated health issues forced me to early retirement at age 54 in Jan 2006.
I have secondary progressive MS, T2 Diabetes and Osteoporosis. Gradually I became obese through a sedentary life style and increasing disability from the ravages of MS”.
MAGNUM SD/XL SPECIFICATIONS
|Frame||7005 Aluminium Alloy, with center fold.|
|Width||34” – 86 cm||36” – 91 cm|
|Length||66 to 76” – 168 to 193 cm *||74 to 84” – 188 to 231 cm *|
|Height||30 to 35” – 76 to 89 cm||31 to 36” – 78 to 92 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||14 to 16” – 36 to 40 cm|
|X-seam range||40 to 50” – 102 to 127 cm **||44 to 54” – 112 to 138 cm **|
|Ground Clearance||6.5” – 16 cm|
|Turning Circle||14 feet – 4.0 metre|
|Track Width||31.5” – 80 cm||33.5” – 85 cm|
|Wheelbase||41.3” – 105 cm||45” – 115 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|
|Cranks||Shun SS-ZO-300 52/42/30 x 165 mm|
|Cassette||9 speed 11/34|
|Front Derailleur||Micro Shift|
|Rear Derailleur||Shimano Deore|
|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|
|Optional Extras||Accessory posts, mirrors, headrest, luggage rack, front mudguards, chain gobbler.|
|Rider weight Limit||400lbs – 180 kg||450 lbs – 200 kg|
|Luggage Weight Limit||88lbs – 40 kg|
|Trike Weight||42 lbs – 19kg||44lbs – 20 kg|
|Boxed Size||33 x 29 x 18″ – 83 x 73 x 47cm||39 x 31x 20” – 98 x 79 x 50 cm|
|Frame Colours||Red, Blue and Yellow|
Laid Back Cycles – Sacramento, NorCal and Bay Area Recumbent Trike Dealer
At Laid Back Cycles we have the top trained mechanics to repair your trike serving the Sacramento and Bay Area.
Come test ride a recumbent trike, 3 wheel bicycle, recumbent, tandem recumbent, three wheel bicycle, trike bicycle, recumbent bike at our store in Fair Oaks, CA near Sacramento. We offer service for Terratrike, Catrike, Greenspeed and ICE trikes.