Get a Quick Quote

Aftermarket Honda CB125F Cylinder Heads — Bulk Supply for B2B Buyers Worldwide

Aftermarket Honda CB125F Cylinder Heads — Bulk Supply for B2B Buyers Worldwide

Honda's CB125F has been the UK's best-selling motorcycle for most years since 2009 — first as the CBF125 (2008-2014), then as the CB125F from 2015 onward. It is the modern successor to the legendary CG125 and the bike most European CBT learners take their first ride on. We supply aftermarket cylinder heads for both generations of CB125F to engine rebuilders, parts distributors, and OEM brands across the UK, Europe, and beyond. Compatible with the 2015-2020 GLR125 platform and the 2021+ eSP platform. MOQ 500 pieces per SKU. Sample orders accepted. 17 years of mass production, ISO 9001 certified, 100% leak-tested on every unit shipped.

Request a Quote

Technical Specifications: CB125F Cylinder Heads

The CB125F has two distinct engine platforms, and they are not interchangeable. The 2015-2020 GLR125 platform uses a 52.4mm bore and 57.8mm stroke. The 2021+ eSP platform uses a completely redesigned engine with 50.0mm bore and 63.1mm stroke — different bore, different stroke, different head casting tooling. We produce both, but you need to tell us which one. Send us the production year or the engine number prefix and we will confirm fitment.

Specification	2015-2020 (GLR125)	2021+ (eSP)
Engine Code	GLR125 (GLR1251WH service code)	eSP engine (Honda SP125 platform derivative)
Engine Type	4-stroke, SOHC, air-cooled, single cylinder, 2-valve, PGM-FI	4-stroke, SOHC, air-cooled, single cylinder, 2-valve, PGM-FI with offset cylinder
Displacement	124.7cc	124cc
Bore × Stroke	52.4mm × 57.8mm	50.0mm × 63.1mm (longer stroke design)
Compression Ratio	9.2:1	10.0:1
Peak Power (OEM)	7.8 kW (10.4 bhp) @ 7,750 rpm	8.0 kW (10.7 bhp) @ 7,500 rpm
Peak Torque (OEM)	10.2 Nm @ 6,250 rpm	10.9 Nm @ 6,000 rpm
Emissions Standard	Euro 3 (2015), Euro 4 (2017+)	Euro 5
Valvetrain	Standard rocker arms, sintered steel valve seats	Rocker arms with needle-bearing rollers (eSP feature)
Piston Cooling	Standard splash lubrication	Oil jet cooling from below (eSP feature)
Cylinder Layout	Standard inline with crankshaft	Offset from crankshaft axis (eSP friction reduction)
Country of Manufacture	China (HSC factory)	Italy (Atessa Honda factory)
Material (Our Aftermarket)	A356 aluminum (JIS AC4CH), T6 heat treated	A356 aluminum (JIS AC4CH), T6 heat treated
Deck Flatness Tolerance	≤ 0.02mm (CMM verified)	≤ 0.02mm (CMM verified)
Valve Seat Concentricity	≤ 0.025mm	≤ 0.020mm (tighter for needle-bearing rocker)
Supply Options	Bare casting / CNC-machined raw / Fully assembled	Bare casting / CNC-machined raw / Fully assembled (with needle-bearing rocker rollers)

Key Sourcing Information at a Glance

Parameter	Detail
Product Type	Aftermarket Honda CB125F cylinder heads — bare castings, CNC-machined raw, or fully assembled. Both GLR125 (2015-2020) and eSP (2021+) variants in production.
MOQ	500 pieces per SKU for standard variants. Sample orders of 50-100 pieces accepted for first-time buyers.
Lead Time	30-45 days for stock variants. 60-75 days for new tooling or custom modifications including racing applications.
Engine Compatibility	Honda CB125F 2015-2020 (GLR125 platform), Honda CB125F 2021-current (eSP platform), and the immediate predecessor CBF125 (2008-2014, shares GLR125 engine architecture with carbureted variants and PGM-FI variants). Heads from the two generations are not interchangeable — verify production year before ordering.
Material	A356 aluminum alloy (JIS AC4CH / ZL101A equivalent), T6 heat treated. LM25 alloy available on request for higher tensile strength variants.
Casting Method	Gravity die casting (standard). Low-pressure die casting (LPDC) available for premium tier, particularly recommended for eSP platform heads given the tighter tolerances around the needle-bearing rocker mounting.
Quality Verification	100% high-pressure leak testing on every unit. CMM dimensional verification on critical features including deck flatness, valve seat concentricity, and rocker shaft bore alignment. Spectrometer-verified material composition. Batch records archived for 5 years.
Packaging	Standard export carton, neutral packaging, or private-label cartons. Generation-coded labels (GLR125 vs eSP) on every batch to prevent warehouse cross-contamination.
Shipping Terms	FOB Ningbo / Shanghai, CIF, or DDP. Strong export experience to UK (Felixstowe, Southampton), Germany (Hamburg, Bremerhaven), Italy (Genoa, Livorno), Spain (Valencia, Barcelona), Netherlands (Rotterdam), and other European entry ports.
Documentation Provided	Material composition certificate, CMM inspection report, leak test pass record, batch traceability documentation, ISO 9001 certificate, REACH compliance statement (for European markets), commercial invoice, packing list, certificate of origin.

The CB125F Lineage — Why the Heritage Matters for Sourcing

The CB125F did not arrive in a vacuum. It is the third generation of a continuous Honda commuter lineage that began with the CG125 in 1976 — over 50 years of small-displacement Honda commuter engineering. Understanding the lineage helps procurement teams identify which generation of head a customer actually needs, because the same buyer might be supporting fleets across all three generations in service. Generation Zero: Honda CG125 (1976-2008) The original. OHV pushrod design, carbureted, indestructible. Sold across the developing world and used as Honda's UK commuter from 1976 until 2008 when Euro 3 emissions made it non-compliant in Europe. Still in production in Pakistan (Atlas Honda) and several other markets. The CG125 head is a separate product line — we cover it on our CG125 cylinder heads page. Generation One: Honda CBF125 (2008-2014) Honda's response to Euro 3. Built in India by HMSI, the CBF125 replaced the CG125 in European markets with a fuel-injected SOHC 2-valve engine that became the UK's best-selling motorcycle from 2009 onward. The engine architecture established here — 52.4 × 57.8mm bore × stroke, 124.7cc, GLR125 codename — continued unchanged into the 2015 CB125F. CBF125 heads and 2015-2020 CB125F heads share the same casting and machining specifications. Engine rebuilders often source these as a single SKU. Generation Two: Honda CB125F GLR125 (2015-2020) Same engine, new bodywork, production shifted from India to China. The 2015 redesign brought new fairing styling derived from the CB500F / CB650F family, improved fuel injection mapping, and a balance shaft. The cylinder head was revised but kept the GLR125 architecture. Demand peaked here — this is the highest-volume CB125F generation in current European aftermarket inventory. Our standard production SKU covers this platform. Generation Three: Honda CB125F eSP (2021-Present) A complete clean-sheet redesign. The eSP ("enhanced Smart Power") engine architecture was migrated over from Honda's scooter line. Bore shrinks from 52.4mm to 50.0mm. Stroke lengthens from 57.8mm to 63.1mm — a longer-stroke design for better low-end torque and Euro 5 compliance. The cylinder is offset from the crankshaft axis to reduce piston-skirt friction. Valves are operated by rocker arms equipped with needle bearings. The piston is cooled from below by an oil jet. Production moved from China to Honda's Atessa factory in Italy. None of this is compatible with the 2015-2020 generation. New tooling, new SKU.

Aftermarket Honda CB125F Cylinder Heads — Bulk Supply for B2B Buyers Worldwide

Who We Supply

For UK and European Engine Rebuilders

The CB125F has been UK best-seller for over a decade, which means there is a large installed fleet of older units now hitting their first major rebuild cycle. Rebuilders typically run parallel inventory for CBF125, 2015-2020 CB125F, and 2021+ eSP heads — three SKUs supporting one platform family. Mixed SKU orders supported (500-2,000 pieces per SKU) with generation-coded packaging. CMM reports on every batch. Sample qualification of 50-100 pieces accepted.

For European Parts Distributors

Private label and neutral packaging available. We drop-ship to consolidation warehouses in the UK (Felixstowe), Germany (Hamburg, Frankfurt), Italy (Milan), Netherlands (Rotterdam), Spain (Barcelona), and France (Lyon). REACH compliance documentation provided as standard for European entry. Distributors handling 20-50 SKUs across the Honda small-displacement range typically batch quarterly orders through our consolidated production schedule.

For Riding School Fleet Operators

A specific UK-centric customer profile — Compulsory Basic Training (CBT) schools run fleets of 20 to 200 CB125F units, which face higher service intensity than private owner bikes. Fleet operators often source replacement heads directly from regional suppliers rather than going through Honda dealer networks for cost reasons. We supply this segment under direct contracts with packaging and documentation tailored for fleet maintenance workflows.

For OEM Brands and Performance Workshops

Long-term OEM supply contracts available with capacity reservation. For aftermarket performance applications, the CB125F has a smaller racing scene than Wave 125 in Southeast Asia — most performance demand involves higher-compression conversions for tracked usage rather than full 4-valve conversions. Small-batch runs (100-500 pieces) accepted for qualified performance brands.

Frequently Asked Questions

What is your minimum order quantity for aftermarket CB125F cylinder heads?

Standard MOQ is 500 pieces per SKU. We accept sample qualification orders of 50-100 pieces for new clients before bulk commitment. For long-term OEM contracts, MOQ structured around annual volume forecast. European fleet operators sometimes consolidate orders quarterly to optimize logistics costs.

How do I identify which CB125F generation a customer needs heads for?

Production year is the most reliable indicator. 2008-2014 CBF125 and 2015-2020 CB125F share the GLR125 engine architecture (52.4mm × 57.8mm bore × stroke). 2021 and newer CB125F use the eSP engine (50.0mm × 63.1mm bore × stroke). The two are not interchangeable. If you have a VIN or engine number prefix, send it to us and we will confirm fitment in writing.

Do you supply REACH and RoHS compliance documentation for European shipments?

Yes. Every shipment to European distributors includes REACH compliance statement on aluminum alloy composition, RoHS documentation where applicable, full material composition certificates from spectrometer analysis, CE-relevant documentation, and ISO 9001 certificate. For UK customers, we provide UKCA-compatible documentation upon request.

Are the CB125F GLR125 and CB125F eSP heads truly not interchangeable?

Correct. The two platforms have different bore (52.4mm vs 50.0mm), different stroke (57.8mm vs 63.1mm), different head bolt patterns, different intake port geometry, and different rocker mounting (the eSP uses needle-bearing rocker arms which the GLR125 platform does not). Installing a wrong-generation head will not bolt up. Always verify production year before ordering.

Do you ship bare castings, machined heads, or fully assembled units?

All three. Bare castings are heat-treated and ready for your own CNC machining. CNC-machined raw heads ship ready for valvetrain assembly. Fully assembled heads ship with valves, springs, retainers, and seals pre-installed — for eSP variants, the assembly includes needle-bearing rocker rollers shaft-aligned to OEM specification.

What is your export experience to UK and European markets?

Extensive. Major destination ports include Felixstowe and Southampton (UK), Hamburg and Bremerhaven (Germany), Genoa and Livorno (Italy), Valencia and Barcelona (Spain), Rotterdam (Netherlands), Le Havre (France). We support FOB, CIF, and DDP terms. Documentation always includes commercial invoice, packing list, certificate of origin, material certificates, ISO 9001 certificate, and REACH statement.

What is the typical lead time?

30-45 days for variants in our standard production library, from PO confirmation to FOB-ready. 60-75 days for new tooling, custom modifications, or racing-spec heads with elevated compression. Bulk reorders on existing tooling ship within 21-30 days for established customers.

Do you also supply CBF125 (2008-2014) cylinder heads?

Yes. The CBF125 shares the GLR125 engine architecture with the 2015-2020 CB125F — the bore, stroke, and cylinder head specifications are essentially the same. We supply the CBF125 head as a separate SKU with specific packaging labeling, though the casting and machining specifications match the 2015-2020 CB125F.

Can your heads handle higher-compression performance applications?

Yes. We produce performance variants up to 10.5:1 compression for the GLR125 platform and up to 11.0:1 for the eSP platform. These require A356 alloy with T6 heat treatment cycle parameters tuned for the higher thermal load. For racing or tracked-only applications, specify target compression ratio, intended fuel grade (95 RON minimum for high-compression variants), and RPM operating range with your inquiry.

What materials and certifications do you use?

Primary alloy is A356 aluminum (JIS AC4CH / ZL101A equivalent), T6 heat treated. LM25 alloy available on request for higher tensile strength applications. Every batch verified by spectrometer before melting, with material certificates shipped alongside the order. Facility certifications include ISO 9001, with recognition as National High-Tech Enterprise and Technology-Based SME of Zhejiang Province.

Why B2B Buyers Source CB125F Cylinder Heads From Feiya

• Production for both GLR125 and eSP platforms — we maintain separate tooling, CMM reference data, and machining fixtures for the two CB125F generations. No platform shortcuts.

• Tighter machining for eSP needle-bearing rocker — ±0.015mm rocker shaft bore alignment, CMM-verified on every unit.

• European compliance documentation as standard — REACH, RoHS, material certificates, and ISO 9001 ship with every batch. No back-and-forth on paperwork.

• Largest cylinder head manufacturer in Yueqing City — 17,000+ m² facility, 5,000+ tons annual aluminum casting capacity, 125+ CNC machining centers, 26 LPDC machines.

• OEM partner to listed motorcycle brands — currently supplying publicly listed motorcycle manufacturers under multi-year OEM agreements. References available under NDA for qualified prospects.

Get a Quote for Your CB125F Cylinder Head Requirements

Send your generation (CBF125 2008-2014 / CB125F 2015-2020 GLR125 / CB125F 2021+ eSP), target volume, destination port, and any European compliance documentation requirements. For OEM partnerships, include technical drawings (STEP/IGES) or OEM sample reference photos. For performance applications, specify target compression ratio and intended fuel grade. Engineering team responds within 24 hours.

+86 13706774970