Ventana’s venerable ECDM (el Conquistador de Montanas) frame has been revitalized with Boost rear spacing. Combined with new tandem-capable fork options and plus tires, the overall capability of this long-time favorite has just increased dramatically!
We use the ECDM frame with the optional Boost rear triangle, which now include Boost 148 thru-axle system as standard. We also now use Boost 110mm forks on most builds, thus allowing more tire clearance on both ends of the tandem.
27.5 x 3.0 tires on 45mm + – rims fit well in both the frame and the forks, and have proven to be quite the improvement, even over 29x 2.35 tires/wheels on 35mm rims. The Plus tire platform offers better rollover capability with the same overall wheel/tire diameter. The plus tire deflects less when riding over trail obstacles such as roots and rocks.
Suspension setups are now typically 108mm rear and 110-120mm front. While a long-travel tandem does indeed wallow a good bit on smooth surfaces under power, travel in the 100-130mm range still behaves well on most surfaces overall, and doesn’t detract from the ride to the fun stuff.
SRAM Eagle 1×12 drivetrains have quickly become the norm as well – the 10×50 cassette seems to offer enough range for most teams, and shifting performance is excellent. We have yet to have a team fold a SRAM Eagle cassette (yet, but it will eventually happen), so durability has been a pleasant surprise. The key is shifting 1 cog at a time, and trying not to shift into a large cog under full power. With these caveats, most teams are experiencing a new high in drivetrain simplicity.
After building 3×9/3×10 with 100mm suspension travel for so many years, it’s quite refreshing to move onto the newer platforms, which lessen the number of tandem-specific parts and systems we now use. New is, in this case, better!
And the final word comes from teams that have moved onto the new platform from both 26″ and 27.5″ wheeled tandems – feedback is that there is a major improvement with the new platform. Check one out when you get a chance, and see what the new level of performance is for off-road tandems!