SOC13: Turner Czar 29er Mountain Bike – Tech Talk & Actual Weights
Turner’s Czar 29er carbon fiber mountain bike was announced on Wednesday, and now we’ve got details directly from Dave Turner about the construction and his first use of carbon fiber.
During development, they provided competitors’ frames to their manufacturing partner’s lab for stiffness testing, which helped set a baseline. This helped the factory better understand what they were looking for, and where they wanted to improve. A few prototypes with different layups were made, and Turner set up the suspension the same across all of them and swapped bikes around between riders to get back to back to back comparisons.
“Some of the bikes were super stiff, which were very efficient in a straight line, but got torsional flex cutting diagonally across ruts,” said Turner. “Carbon’s exciting because of the tunability. The goal for me was to make something that rides well and wasn’t so stiff that it passed impact forces on to the rider, but it needed to be torsionally stiff so the wheels kept in plane when hitting off camber stuff and rough terrain.”
Rock past the break to see it on the scale and more…
Being their first carbon bike, Turner says they punished it in lab testing with higher cycles and heavier loads than safety standard require. Even so, all of their rideable test samples are still in the field being ridden, even after passing EN safety testing.
Lest you think this is the beginning of the end for his US-made bicycles and business, frame parts are being brought in then checked and assembled in the USA. And, he hinted there’s something else metal coming later this year.
Getting the chainstays so short required a lot of back and forth with Dave Weagle. Shown above are the starting position of the bike with no sag on the left, and full compression shown on the right.
Check out how close the lower yoke is to the BB shell!
During compression, the chainstays move up and round the seat tube.
Mounts for dropper post cable guides are on the bottom of the downtube. Not using a dropper? They’ll all but invisible.
We hung our scale upside down and zeroed it, but the closeup is rotated to show the 22lb 11oz total. Pretty good considering the build with alloy Thomson post and stem, ENVE wheels and alloy-crown SID fork on an XX1 drivetrain.