ethirteen Helix Race Carbon espec Cranks for ISIS Spindle - 160mm, 26mm Offset, Graphite

The ethirteen Helix Race Carbon espec Cranks represent the absolute pinnacle of lightweight e-bike drivetrain engineering. Delivering an industry-leading strength-to-weight ratio, these 160mm carbon fiber crank arms are ASTM 5 rated to handle everything from aggressive all-mountain lines to demanding bike park laps. Featuring a 26mm offset for optimized motor casing clearance and a balanced stance, they come complete with integrated alloy self-extractors and custom-molded protective boots to provide race-ready elite performance.

e*thirteen Helix Race Carbon e*spec Cranks for ISIS Spindle Motor Systems - 160mm, 26mm Offset, Graphite

The e*thirteen Helix Race Carbon e*spec Cranks represent the pinnacle of ultralight carbon e-bike engineering, delivering the highest strength-to-weight ratio available in the e-MTB world today. Developed through years of intensive carbon fiber layup optimization and advanced high-pressure compression molding, these premium carbon crank arms are purpose-built for discerning riders and pro-level racers looking to shed serious rotational mass. Despite their remarkably low weight, they maintain the precise structural rigidity and elite power transfer needed to maximize motor efficiency under heavy torque loads.

This model is engineered for standard ISIS spindle motor interfaces, providing clean, factory-level integration across the industry's leading high-output e-bike platforms. It is extensively compatible with Bosch CX Gen 4/Gen 5, Bosch SX, TQ HPR50, Brose S Mag, DJI Avinox, Yamaha, and Specialized 2.2/3.1 systems. Featuring a wide 26mm offset, these cranks achieve a generous 186mm Q-factor, ensuring absolute mechanical clearance around wide, modern chainstays and bulky rear suspension pivots while providing a highly stable, centered stance for maximum technical control on descents.

At a progressive, short 160mm length, these crank arms striking the ultimate sweet spot between raw pedaling leverage and vital ground clearance on modern, low bottom-bracket frame geometries. Shorter carbon arms allow you to maintain a fast, uninterrupted pedaling cadence through technical, rock-strewn climbs—substantially decreasing pedal strikes while keeping your motor operating in its most efficient RPM range. For simple, hassle-free maintenance, the arms feature integrated alloy self-extracting crank bolts that streamline installation and routine home workshop service.

Weighing an incredible, featherweight 326g, these elite cranks carry an unconditional ASTM 5 certification, ensuring they are light enough for fast-paced trail riding yet rugged enough to dominate brutal shuttle days at the bike park. Finished in a premium matte graphite carbon finish, they include custom-molded protective crank boots that serve as a high-impact shield against flying trail debris and inevitable rock strikes. Designed for weight-conscious, high-performance e-bike builds, the Helix Race Carbon e*spec cranks are backed by e*thirteen's dependable 5-year manufacturer warranty.

Key Features

• Premium Compression-Molded Carbon Fiber: Elite engineering deliver the ultimate strength-to-weight ratio, optimizing stiffness while removing major rotational weight


• ASTM 5 Category Approved: Lab and trail certified to withstand the extreme forces of high-speed gravity racing, bike park laps, and enduro singletrack duty


• Optimized Short 160mm Length: Maximizes ground clearance on low-BB frame designs to eliminate pedal strikes while maintaining natural leverage and pedaling fluidics


• Generous 26mm Wide Offset Profile: Delivers a balanced 186mm Q-factor, providing maximum clearance for wide chainstays and complex rear pivot designs


• Standard ISIS Spindle Interface: Broadly compatible with Bosch CX Gen 4/5, Bosch SX, TQ HPR50, Brose S Mag, DJI Avinox, Yamaha, and Specialized systems


• Integrated Alloy Self-Extractor: Heavy-duty self-extracting bolt configuration makes installation and routine drivetrain maintenance efficient and tool-free


• Huckproof Crank Boots Included: Ships with custom-fitted, impact-absorbing protective composite boots to safeguard your carbon investment from trail strikes

Specifications

• Model: e*thirteen Helix Race Carbon e*spec Cranks


• Crank Arm Length: 160mm


• Spindle Interface Type: ISIS Spindle


• Crank Offset: 26mm


• Realized Q-Factor: 186mm


• Motor System Compatibility: Bosch CX Gen4/5, Bosch SX, TQ HPR50, Brose S Mag, DJI Avinox, Yamaha, Specialized (2.2/3.1)


• Material: World-Class Optimized Carbon Fiber Layup


• Extraction Mechanism: Integrated Alloy Self-Extractor System


• Protective Hardware: Molded Composite Crank Boots Included


• Weight: 326g (+/- variation tolerance)


• Color: Graphite


• Warranty: 5 Years

The ultimate elite carbon e-bike crank arm upgrade, combining an incredibly light 326g profile with ASTM 5 gravity-rated strength and a generous 26mm offset for riders who refuse to compromise on weight, clearance, or durability.