Pole's 29-inch-wheel Stamina 140 is a shorter travel, more nimble rendition of the brand's vanguard geometry, packaged in a chassis that has evolved considerably since the Machine debuted a little more than a year ago.
We met with founder and designer Leo Kokkonen to find out what he had learned from the original Machine and how he applied those lessons to the new Stamina. Kokkonen said the Stamina's aluminum frame is still CNC machined from 7075 aluminum plates and bonded together in halves.
Unlike the Machine, however, which employs small screws to assist the bonding process and further secure the matching sections of the frame, the new chassis is glued together using a new patented interface and bonding process. The Stamina's profile is "much more normal," says Kokkonen, and some of that was a product of the designers' vigilant efforts to reduce the amount of waste and to further simplify the manufacturing process.
Much material has been removed from the frame's front section. The head tube area has been lightened and the Machine's seat tube tunnel has been replaced by a yoke, which drives the top tube mounted shock. Kokkonen says that the big improvements were out back, however. The swingarm is no longer bonded into one piece. Instead, the right and left sides are machined and bonded separately, then assembled onto keyed axles. The upper and lower suspension rockers are also keyed into the axles.
When asked if there may be reliability issues, Kokkonen explained: "The way the swingarm halves and linkage plates fit together is very much like the bottom bracket and crank arms, Crankarms see much greater forces with zero problems. I am just moving that interface to the suspension."
The new design uses smaller, flatter aluminum billets, which saves a lot of machining and also streamlines both the bonding and final assembly process. Should a customer destroy part of the rear suspension in a crash, individual components can be easily replaced.
Eliminating the seat tube tunnel also makes room for longer dropper posts, which is essential due to the Stamina's low-stand-over height and steep, 77.5-degree seat tube angle. (78.6 effective). With the post nearly centered between the wheels, you need stow the saddle as low as possible for the downs. Kokkonen says he rides a 170-millimeter dropper but may switch to a 200.
Geometry is all Pole, with a 64-degree head tube angle, 450-millimeter chainstays and a still massive, 520-millimeter reach in the XL size, it's guaranteed to be a hoot on any downhill. The wheelbase, says Kokkonen, is only 15 millimeters less than the long travel models, but the differences are significant under saddle.
Different suspension kinematics produce anti-squat numbers well above 100 percent and reportedly, a better feel under power, especially while climbing. The 140 millimeter-travel Stamina gave up a little speed to the 180-millimeter travel version on timed descents, but Kokkonen concedes that the new bike feels more lively and fun to ride, even if that comes with a measure of upper body fatigue that you'd never experience aboard the Machine.
This is the first Stamina 140 that Pole has produced and will undergo intensive testing when it travels back to Finland. If all goes as planned, customers could be riding them this summer. Look forward to a PB review when that moment arrives.