Why is the V2r the absolute best racing tandem on the market? Crossover drive left-side transfer chains (or belts, more recently) are the product of bicycle evolution, which graduated from single drive chain rings to double, and then triple, chain rings for the main drive to provide wide-range gearing for a variety of riding conditions. Triple chain rings take up so much space on the right side that there’s no room left for the transfer ‘rings or sprockets; hence, designers moved the transfer drive to the left side where space was plentiful. But, with that comes several inherent disadvantages:
- Tandem-specific cranks are required with a spider or other mount for the transfer sprockets
- Three spider-mount crank arms are required, which adds to the weight of the system
- The rear bottom bracket experiences high loading due to the force of three riders’ legs (both of the captain’s plus the left stoker’s leg) being transmitted through the rear crank axle.
- Both torque and bending forces are significantly higher—as much as three times as high—as on a comparable single bike, resulting in either reduced component lifetime or higher weight, or both.
- Modern belt transfer drives on a tendem’s left side, place much higher loads on the bearings due to the higher tension required compared to a traditional transfer chain.
The Paketa V2r tandem (patent pending) eliminates all of these problems in one elegant, integrated, and game-changing design. By mounting the transfer drive sprocket on the same crank spider, behind the main drive sprockets in the rear, all of the disadvantages of the conventional left-side-drive design are eliminated. Conventional single-bike cranks can be used for both the captain’s and stoker’s cranks, for starters. This allows the use of almost any crank, including state-of-the-art light weight carbon cranks, of any crank length to suit either rider. Because the bearing and axle bending loads are no higher than on a single bike, there’s no stiffness or durability penalty for using the very lightest single-bike cranks available—note the Zipp™ carbon cranks on the V2r in the photos. The transfer drive (Gates Carbon Drive™ belt system shown) is mounted far inboard on the right side, which also reduces frame bending in the boom tube under hard pedaling. Even all-out sprints by the strongest riders won’t cause frame “whip” and the unpredictable handling that results.
Because of the innovative “compact open” low-top-tube design, frame sizes become almost irrelevant. Standover height is ample for almost anybody front or rear, and with a 72.5 cm (28.5”) stoker top tube you’ll never hear any complaints of cramped rear quarters. A quality adjustable stoker stem helps to fine tune the fit of the stoker. The V2 is available in a small, medium, large, and extra-large with different length captains top tubes. Captain’s top tubes are available in standard lengths (measured horizontally) of 54, 56,58, 61 cm. For a modest upcharge, custom geometry is also available; please inquire.