Factory Inventory & Drivetrain Catalog
Featured MTB Drivetrain & Component Portfolio
Direct from our onsite-verified Shenzhen facility to Port of Los Angeles (POLA) & Port of Long Beach. Explore professional mountain bike components and high-turnover bike accessories tailored for US commercial accounts.
Engineering Whitepaper
Structural Architecture of CE-Certified MTB Cranksets
Technical compliance under EN ISO 4210-2 requirements: Fatigue lifecycle, spindle torsional stiffness, and integrated bottom bracket sealing mechanics.
Cold-Forged 7075-T6 Arms
Our factory processes high-purity aluminum billets through a 1,200-ton hydraulic forging press followed by T6 artificial aging. This grain-alignment process eliminates structural voids, achieving a minimum yield strength of 503 MPa and an ultimate tensile strength exceeding 572 MPa, easily surpassing dynamic load fatigue tests (100,000 cycles at 1,800N dynamic pedal stroke force).
24mm Cr-Mo Hollow Spindle
Heat-treated 4130 Chrome-Moly and optional 7075 aero-spindles undergo centerless grinding to ±0.005mm tolerances. The hollow axle configuration yields maximum torsional rigidity across intense singletrack accelerations, fully eliminating the spindle twist and micro-flex common in budget square-taper or splined ISIS interfaces.
Dual-Sealed Outboard BB
Each integrated bottom bracket incorporates high-precision Japanese SUJ2 chrome steel bearings packed with waterproof synthetic marine lubricant. Precision CNC-threaded English BSA cups (68/73mm shell compatibility) feature custom dual-lip elastomeric contact seals that keep high-pressure trail wash, sand, and coastal moisture at bay.
100,000+
Fatigue Cycles Tested
±0.005mm
CNC Machining Accuracy
≤ 4 Hours
Average Inquiry Response
97.41%
Verified Fulfillment Rate
Regional Market Alignment
Engineered for Los Angeles Riding Terrain & Assembly Demands
Southern California represents one of the largest aggregate markets for progressive enduro, downhill, and heavy-duty urban e-bike commuting in North America.
San Gabriel & Santa Monica Trails
From Mount Wilson and Mount Lowe descents to the rocky drop-offs of Topanga State Park, local riders demand crankarms that resist harsh pedal strikes against granite rock faces. Our impact-tested aluminum arm geometry dissipates transient shock waves away from the spider interface, preventing premature crank shear during aggressive downhill runs.
Coastal Marine Atmosphere Resiliency
Bike shops in Long Beach, Santa Monica, and Newport Beach deal with aggressive salt fog corrosion. Our cranksets utilize Mil-A-8625 Type III Hardcoat Anodizing (thickness ≥ 25μm), while bottom bracket bearing tracks are coated with specialized phosphated passivation, guaranteeing zero galvanic seizing inside threaded alloy bottom bracket shells.
OEM Assembly Lines in Southern California
With boutique bike brands and custom e-mobility builders centered in Irvine, City of Industry, and Torrance, our factory provides pre-faced BB spacers, pre-torqued self-extracting bolts, and tailored chainline offsets (52mm Boost and 49mm Non-Boost), cutting frame assembly times by up to 18% on volume production lines.
Procurement Intelligence
B2B Sourcing Trends Across California Bike Importers
How US distributors, retail co-ops, and private label brands are optimizing supply chains amidst fluctuating ocean freight and strict regulatory standards.
1×12 Speed Narrow-Wide Dominance
Front derailleurs are virtually obsolete across the Los Angeles mountain bike and electric gravel community. The demand has shifted exclusively to 30T, 32T, 34T, and 36T CNC 7075-T6 narrow-wide chainrings with symmetrical drop-stop tooth profiling. Buyers require chain retention verification over rough terrain without an auxiliary chain guide.
Port of LA DDP Consolidated Logistics
Importers are sidestepping domestic port demurrage and split logistics by demanding full DDP (Delivered Duty Paid) shipping solutions. Harke provides direct container handling straight from Shenzhen factories through Long Beach customs clearance to warehouse doorsteps across Ontario, Vernon, and Santa Fe Springs.
Stringent EN ISO 4210 Compliance
Product liability risks in California make uncertified drivetrain parts uninsurable for mid-to-large distributors. Procuring crank assemblies verified by accredited third-party laboratories (CE / EN ISO 4210-2 Category 4 and 5) gives retail chains immunity against catastrophic breakage claims during high-impact trail riding.
Factory Qualifications & E-E-A-T Authority
Why Top Cycling Brands Choose Harke as Drivetrain Partner
Founded in 2019 in Shenzhen's precision manufacturing belt, we unite rapid R&D turnaround with rigorous ISO quality control and transparent B2B contract terms.
Onsite-Verified Production
Our 1,000–3,000 m² facilities have passed complete on-site inspection. Every forging die, CNC toolhead, and assembly station adheres to documented process control sheets.
≤ 4h Response Guarantee
With an ongoing 97.41% inquiry response rate, our bilingual engineering sales teams provide rapid RFQ quotes, CAD drawing approvals, and material breakdown sheets.
Flexible MOQ Scalability
Whether you need pilot sampling runs from 1 set to validate frame fitment or full 40-foot HQ container freight, our production scheduling flexibly adjusts to market demand.
Diverse Incoterms & Currency
We accept USD, EUR, GBP, CAD, and AUD across T/T or Western Union under FOB, EXW, DDP, and DDU shipping terms, drastically simplifying cross-border bookkeeping.
Buyer Knowledge Base
Frequently Asked Questions for California Importers
Everything you need to know about specs, shipping to California ports, testing documentation, and OEM branding options.
Are your MTB crankset and bottom bracket sets compliant with CE and California standards?
Yes. All our MTB crankarms, hollow spindles, and threaded bottom brackets undergo stringent mechanical fatigue and tensile testing compliant with CE directives and EN ISO 4210-2 (Mountain Bicycles Safety Requirements). Furthermore, surface anodizing and raw alloys comply with California Proposition 65 requirements regarding lead and heavy-metal thresholds. Complete test reports are provided with commercial invoices.
What bottom bracket standards do you manufacture for US frame geometries?
We manufacture threaded external English BSA cups (68mm and 73mm BB shells) with standard 1.37"×24 TPI threading, which covers over 80% of mountain bike and aggressive gravel frames in the US market. We also provide press-fit BB92 (41×89.5/92mm) bottom brackets with 24mm continuous spindle adapters, ensuring complete compatibility with Boost 148mm and standard 142mm rear-hub frame dropouts.
What is the transit time and port clearance workflow to Los Angeles / Long Beach?
Typical ocean freight transit from Shenzhen (Yantian/Shekou) to the Port of Los Angeles (POLA) or Port of Long Beach takes approximately 14 to 18 days on direct vessels. Under DDP terms, our dedicated freight forwarder manages ISF filings, single-entry customs bonds, harbor maintenance fees, and dock drayage directly to your warehouse across the LA basin, avoiding third-party container demurrage spikes.
Can we order custom laser etching and customized anodized colorways for our brand?
Absolutely. We provide full OEM, design, and buyer-label branding services. We can precision laser-etch your company logo, torque specifications, and QR track-codes onto the crankarms. Chainrings and BB cups can be anodized in custom Pantone hues (e.g., deep orange, anodized purple, olive green, matte stealth black) with custom full-color retail packaging and barcode inserts.
What are the MOQ terms for custom OEM crankset specifications?
For standard off-the-shelf samples and fitment prototypes, our MOQ starts at just 1 set. For custom laser-engraved logos on standard black anodized crankarms, the minimum run is typically 50 sets. Fully customized CNC tooth profiling or special anodizing color batches generally require an MOQ of 100 to 200 sets per SKU, allowing boutique brands to trial new model lines without capital overexposure.