Short 160mm alloy eCrank arms for eMTBs whose motor uses a steel ISIS-spline spindle: TQ HPR50 and HPR60, Brose Mag family, Fazua Ride 50, Bafang M800 and SRAM Powertrain. The shorter arm gives more pedal clearance.

Highlights

  • Type 3 MTB arm shape for ISIS-spline motors
  • For TQ HPR50/HPR60, Brose Mag family, Fazua Ride 50, Bafang M800 and SRAM Powertrain
  • Alloy left and right arms, 160mm
  • Replaceable M24 alloy main bolt with built-in self-extractor, 8mm hex, 50Nm

Fitting

Fitting eCrank arms is a separate workshop service and isn't included in the price. The Tune workshop can fit them and confirm your motor and spindle first. Praxis specifies a torque wrench with an 8mm hex for the M24 main bolt (50Nm). The bolt comes pre-installed and doubles as a self-extractor, so the arm comes off with the same 8mm hex. Praxis's manual says to re-check the torque after about the first 100km.

Which Praxis eCrank type fits?

Praxis sorts its eCranks by the motor's spindle and the arm shape. Its fit guide (April 2026) matches them like this:

  • Type 1: older Bosch Gen4 CX (BDU37) and SX (BDU31), Yamaha PW-X, Giant SyncDrive Pro
  • Type 2 (MTB): Bosch Gen5 CX (BDU38) and PX (BDU34), Avinox (DJI) M1/M2/M2S, Qore (Brose) Drive3, Specialized Levo 4
  • Type 3 (MTB): Brose S-Mag, TQ HPR50/HPR60, Fazua Ride 50, Bafang M800, SRAM Powertrain
  • Type 4 (narrow road/gravel): Brose S-Mag, Fazua Ride 50, TQ HPR50/HPR60, Giant E+ BBSS
  • Type 5 (road/gravel): TQ HPR40
  • Type 6 (ETOR alloy spindle): Fazua Ride 60 and Maxon AIR-S (MTB and road/gravel), Mahle M40 (MTB)
  • Specialized Turbo-ISIS: Gen 1–3 Levo, Kenevo, Vado, Como (asymmetric arms)
  • M30/SL1.1: Specialized SL 1.1 motor

Compatibility & fit

Type 3 arms fit these motors on their steel ISIS-spline spindle. Praxis publishes these Type 3 Q-factors without separating carbon and alloy arms:

MotorQ-factor
TQ HPR50 / HPR60171mm
Fazua Ride 50171mm
Bafang M800183mm
Brose Mag family (S-Mag)186mm
SRAM Powertrain186mm
  • Not for Specialized Gen 1–3 Levo, Kenevo, Vado or Como. Praxis says not to order this crank for them (see Praxis Specialized Turbo-ISIS).
  • For road, gravel or urban eBikes with the same Brose, Fazua or TQ motors, Praxis makes the narrower Type 4.
  • Not for Fazua Ride 60 (ETOR spindle, Type 6), TQ HPR40 (Type 5), or Bosch, Avinox and Brose Drive3 (Types 1 and 2).
  • Left and right arms only. No chainring is included.
  • Unsure what your bike has? Check your motor's crank interface with our workshop before ordering.
Praxis warrants its components to be free from defects in materials or workmanship for two years from the original purchase date, to the original owner with proof of purchase. The warranty does not cover normal wear and tear, products installed incorrectly or damaged by the wrong installation or removal tools, crash, impact or abuse, or any modification. This is in addition to your rights under the Australian Consumer Law, so keep your proof of purchase. For warranty support, return the product to Tune Cycles and we'll manage the claim with Praxis's Australian distributor.
  • Type 3 MTB arm shape for steel ISIS-spline motors
  • For TQ HPR50/HPR60, Brose Mag family, Fazua Ride 50, Bafang M800 and SRAM Powertrain
  • Alloy arm set, left and right, 160mm
  • M24 alloy main bolt and self-extractor, pre-installed
BrandPraxis
ModelEC-Type 3 (EC-3) MTB alloy
Crank length160mm
UseeMTB
Motor interfaceSteel ISIS-spline spindle
MotorsTQ HPR50/HPR60; Brose Mag family (S-Mag); Fazua Ride 50; Bafang M800; SRAM Powertrain
MaterialAlloy
ContentsLeft and right crank arms
Q-factor (Type 3, Praxis)TQ and Fazua Ride 50 171mm; Bafang M800 183mm; Brose Mag and SRAM Powertrain 186mm
WeightPraxis average for the alloy set: 520g
Main boltM24 alloy main bolt / self-extractor, 8mm hex, 50Nm
SKU DSG-PXEC-3ISIS-160AM
Brand Praxis

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