Big Wheel and Gearing
The large 26” rear wheel of the Magnum BW has a number of advantages over the 20” of the Magnum SD. Instead of needing the special 52/42/30 crankset of the Magnum SD, the Magnum BW uses the standard Shimano Sora 50/39/30 crankset so replacements will be easy to get. Another advantage is the larger wheel lifts the rear derailleur and chain further from the ground, so that the trike is more suited to off road use. Plus, as the 26” wheel is the most common size bike wheel, there are a greater selection of tires available. Finally, the larger rear wheel just LOOKS better than having the same size wheels all round.
In the interests of saving money some trikes have twist grip shifters. While this might be OK on an upright bike with horizontal handle bars where one can get one’s thumb and fore fingers around them, they are awkward to use on vertical handle bars, where one can only get the two smaller fingers around them. Thus the Magnum BW uses the Shimano Dura Ace Bar End shifters which make changing gear easier. Also the Magnum BW has a special MicroShift front derailleur which only needs ½ the force required by the Shimano Sora F/D. We also found that the 11 speed chains now in common use were only lasting a fraction of the mileage obtained from 9 speed chains, plus the 11 speed gears needed more frequent adjustment. Plus, witnessed by the fact that a number of people are choosing to ride single speed machines, it was obvious that 11 rear speeds were not needed. Thus the Magnum BW has “only” 27 speeds.