Wilwood GP310 Front Brake Caliper — 4-Piston Billet, Harley-Davidson 2008–2026

Wilwood's GP310 is the front caliper upgrade Harley riders have run for years — a 4-piston billet aluminum caliper that bolts directly to the fork leg of 2008–present Harley-Davidson motorcycles. Stainless steel pistons resist corrosion and help control brake fade, high-temperature seals keep lever feel consistent, and the pad anti-rattle clip keeps things quiet. Choose your finish and side; dual-disc front ends take one Left and one Right.

FITMENT

Fits 2008–2026 Harley-Davidson Touring models — Road King, Road Glide, CVO Road Glide, CVO Road Glide ST, Electra Glide, Street Glide, Limited and Ultra (fitment as published by Wilwood: 2008 to present Harley-Davidson motorcycles, direct leg-mounted for single and dual disc models). Built for rotors 0.18–0.25 in thick and up to 11.80 in diameter — the factory 2008+ Touring front rotor size.

Not sure it fits your bike? Email info@norcalbaggersupply.com — email is the fastest way to reach us — and we'll confirm before you order. You can also call 916-626-9030 (Mon–Fri, 9 AM–5 PM PT).

SPECIFICATIONS

• Manufacturer: Wilwood — part numbers 120-12116-BK / 120-12117-BK (Black) and 120-12116 / 120-12117 (Chrome), shown on each variant
• Caliper: GP310 4-piston, CNC-machined billet aluminum
• Pistons: four 1.25 in stainless steel, 2.46 sq in total piston area
• Mount: direct leg mount, 2.72 in lug spacing — no bracket required
• Rotor range: 0.18–0.25 in thick, up to 11.80 in diameter
• Brake pads: Wilwood BP-10 on plate 6208 (pad area 3.65 sq in)
• Inlet thread: 3/8-24
• Weight: 2.1 lbs
• Sold individually — order Left and Right for a dual-disc front end

INSTALLATION

Bolt-on — the GP310 mounts directly to the fork leg at the factory caliper location. Torque the mounting bolts and bleed the system per your Harley-Davidson service manual, and bed the pads per Wilwood's pad procedure. No official Wilwood install video exists for this caliper — installation is manual-only.

QUESTIONS RIDERS ASK

Is this price for one caliper or a pair?
One caliper. Left and Right are separate part numbers — a dual-disc front end needs one of each from this listing.

Do I need a mounting bracket?
No. The 2008-up GP310 is a direct leg-mount caliper with 2.72 in lug spacing — it bolts to the fork leg where the stock caliper sat.

Which brake pads does it use?
Wilwood BP-10 pads on plate 6208. We stock the replacement pad set — search the store for “Wilwood BP-10 Brake Pad Set”.

Will it work with my stock front rotor?
Yes — it is built for rotors 0.18–0.25 in thick up to 11.80 in diameter, which covers the factory 2008+ Touring front rotor. Pair it with Wilwood's drilled stainless rotors for the full upgrade.