Inspired X7 Design
While most trike manufactures use 20” wheels against 26” for strength, there is an old saying in bicycle circles that “An ounce off the wheels, is worth a pound off the frame.” In testing we also discovered that 16” wheels rolled easier than 20” wheels. This is also the reason why small wheeled bikes like the Moulton have been banned from international bike racing by the UCI. They are too fast! The other advantage of the 16” wheels is they feed less force into the frame under cornering, and thus the whole frame can be lighter. Thus, like the SLR Race Trike, and most Pedal Prix racing trikes, the X7 uses 16” wheels all round, to make a lighter, faster, and more compact machine.
Yet another advantage of small wheels is they require less torque at the rear hub to push the trike along, thus it is possible to use a 9t cog on the back instead of the standard 11t top gear cog, yet have a smaller tooth loading than with a 26” wheel. Thus, with the 56/40/28 triple crankset, and the 9/32 cassette, the X7 has a higher top gear (106 inches) than the standard trike with the standard 52/42/30 cranks, an 11/32 cassette and a 20” rear wheel (95 inches). Plus the X7 has a wider gear range of 588% V the standard 504%.
To improve the road holding over the GT20, besides using the smaller 16” wheels (actually 17.0” OD) the frame has been dropped to further reduce the centre of gravity, yet like the GT20, the seat height is adjustable, from 10” to 15”, plus the recline is adjustable.Thus you should be able to find a combination which is ideal for your riding style.