Praxis Turn M35 mountain bike crankset

Praxis has been developing Turn cranks in order to offer OEM solutions for brands that want to spec their chainrings on production bikes. The cranks are all hollow cold forged in their own factory.

For mountain bikes, the cranks will be offered with a 30mm spindle or a massive 35mm spindle for ultimate stiffness. The 30mm option, like the road one, will fit in any BSA/BB30/PF30 frame. The 35mm crankset will only fit in BB30/PF30 frames.

Why 35mm? Praxis’ marketing director Adam Haverstock says it allows them to make the spindle from thinner walled alloy, which makes them stiffer for approximately the same overall weight. Combine that with the wider stance of their outboard bearing bottom bracket conversions and you get something massively stiff.

Check the comparison and plenty more below…

Praxis Turn M35 mountain bike crankset
The 35mm spindle (top) compared to 30mm spindle.

When the MTB cranksets launch, they’ll have new 2x chainrings to go with them. They wanted to introduce both at the same time because it allows them to control the chain line, and thus the shifting experience.

Praxis Turn R-Series road bike crankset

For road, they’ll be in the Force/Ultegra level, and at SLX/XT level in terms of weight, performance and price. Weights are still TBD, they just finished tooling and are finalizing production methods and such.

Praxis Turn R-Series road bike crankset

The road R-Series has a 30mm spindle designed around a 68mm BB shell, but it can be used with any frame. They use their own outboard bottom bracket to fit the larger spindle in a BSA 68 threaded frame. Or, you could use their outboard 30mm BB to fit it in a BB30 or PF30 frame. One crankset, most frames (not BBright or BB386. Yet.)

They’re doing a ton of testing this summer and should have final versions shown at the fall tradeshows.

Praxis Campagnolo PFBB30 bottom bracket adapter

For Campagnolo fans, they’ll have Ultra-Torque crankset conversion kits to run Campy cranksets on BB30/PF30 or Specialized OSBB 61mm bottom bracket shells. The silver clip spring is for bearing retention a la Campagnolo’s design.

Praxis outboard bearing BSA bottom bracket for BB30 cranksets

One particularly cool bottom bracket they’ve had in their line for a while is the outboard BSA-to-BB30 model. Using external cups with oversized bearings and larger, 30mm ID, they let you run BB30/PFBB30 cranksets on any standard 68mm threaded BB frame.


  1. So road cranks with a 30mm spindle that will fit in a threaded frame? But not wide enough for a BB386 frame? So now we’ve got 30mm spindles in four different lengths? (BB30/PF30, BBRight, Praxis, BB386)

    Stop it. Just stop it.

  2. The comment above about running BB30 cranks on a standard 68mm BSA frame is just plain wrong: the bearing spacing on the BSA frame with external cups will be wider than the BB30 setup and any true BB30 crank will not work with it. A Zipp Vuma, Rotor 3D+, etc will work, but those are not BB30 cranks… just cranks with a 30mm spindle.

  3. Actually I believe that 68mm BSA + external cups will yield an 86mm outer dimension and work with BB386 cranks… just not BB30 cranks.

  4. I’m glad that external bearing BBs (a compromise design if ever there was one) are on the way out, but too many companies are taking advantage of the current uncertainty to introduce their own superfluous take on the BB.

  5. Article should read: “For mountain bikes, the cranks will be offered with a 30mm spindle or a massive 35mm spindle for ultimate incompatibility, and reduced bearing life.”

  6. Pretty sure these guys REALLY know what they are doing. Their chainrings are amazing, the way these BB’s assemble are really cool and the engineers behind it are top notch. Praxis, contrary to popular belief, offers solutions, not hurdles

  7. I am only 25 but remember sq taper cranks like it were yesterday and yes, various length spindles and various width shells. Engineered to accommodate the various drive-train ,frame and component combination, as well as rider preference(q-factor*) Threads admittedly are the downfall here. French, Italian, English who knows how to tell what it is?
    Why is it that today’s technology does not appear to cater to these needs but rather manufacture compatibility? Are we being forced to accept new bottom bracket interfaces because of the benefits at the frame production level? Why can’t we have standards?

What do you think?