Pinhead Seat Collar
Seat Collar
Seat Collar
Pinhead

Pinhead Seat Collar

$18.99
In Stock

Pinhead PH-117 seat collar add-on fits 34.9mm (1.4") seatposts and expands 3- or 4-pack lock sets for secure, low-profile seatpost protection.

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Product Details

Overview & Technology

Pinhead's PH-117 seat collar add-on is a purpose-built accessory that lets you expand your existing Pinhead lock set to protect an additional seatpost. Designed as an add-on for 2, 3 and 4-pack lock systems, this compact collar clamps around 34.9mm (1.4") diameter seatposts to provide a discrete, tamper-resistant retention point for Pinhead locking mechanisms. Constructed from precision-machined 6061-T6 aluminum with corrosion-resistant hardware and a tough protective finish, the collar balances strength and featherlight weight. The low-profile shape keeps the look of your bike clean while delivering the same security interface as the main Pinhead lock pieces.

Key Features & Benefits

Durable materials: Machined aluminum body and stainless fastening hardware resist rust and hold up in wet, salty conditions — essential for year-round riders. Low weight, high security: At just a few grams, the add-on adds virtually no weight to your bike while enabling the Pinhead locking system to secure seatposts against opportunistic theft. The slim profile also minimizes interference with frame bags and seatpost-mounted accessories.

Fit, Compatibility & Installation

This PH-117 collar is specifically sized to fit a 34.9mm (1.4") diameter seatpost and is intended as an add-on for existing Pinhead 2, 3 and 4-pack lock sets. It pairs with Pinhead’s standard lock barrels and mounting hardware — not sold as a standalone full lock; you'll need the main Pinhead lock set to make it functional. Installation is straightforward: position the machined collar around the seatpost, align the mating surface with your Pinhead lock interface, and secure using the provided stainless fastener. A single hex key is usually all that's required; typical install time is under five minutes. If you run an unusual post clamp or large setback post, verify clearance before purchase.

Who This Is For

Road riders, commuters and bikepackers who use multiple bikes or want to protect a non-standard seatpost diameter will appreciate this add-on. It's ideal if you already own a Pinhead multi-pack lock set and need to extend protection to a bike with a 34.9mm post — race bikes, aero seatposts with external collars, and alloy posts are common use cases. It’s also a good choice for bike shops and fleet managers who maintain several frames and want a simple, low-cost way to add an additional locking point without buying a whole new lock set.

Key Features

  • ✓ Fits 34.9mm (1.4") diameter seatposts for broad compatibility
  • ✓ Add-on designed for Pinhead 2, 3 and 4-pack lock systems
  • ✓ Precision-machined 6061-T6 aluminum body for strength
  • ✓ Stainless steel fastening hardware resists corrosion
  • ✓ Ultra-low weight keeps bike handling unchanged
  • ✓ Low-profile design preserves bike aesthetics and clearance
  • ✓ Quick install with common hex key—install in minutes

Product Identifiers

Vendor Item # PH-117
UPC 853583001175

Frequently Asked Questions

Will this collar work by itself as a seatpost lock?

No. The PH-117 is an add-on collar that provides the mechanical interface for a Pinhead locking barrel. You must pair it with a Pinhead lock barrel from a 2, 3 or 4-pack set to create a functioning lock.

What tools are required for installation?

Installation typically requires a single hex (Allen) key—usually 4mm or 5mm depending on the supplied fastener. No special tools are needed and most riders can install it in just a few minutes.

Is the collar compatible with carbon seatposts?

The PH-117 is sized for a 34.9mm diameter post. While the collar itself is lightweight and low-profile, we recommend checking your carbon seatpost manufacturer's clamp torque specs and using a thin protective layer (e.g., carbon paste or a split shim) to avoid overtightening or point loads on carbon.

How weather-resistant is the collar?

The collar features a corrosion-resistant finish on a machined aluminum body and uses stainless steel hardware, so it withstands rain, road salt and typical outdoor storage. Regular maintenance—periodic cleaning and a drop of lubricant on the fastener—will keep it operating smoothly.

Can I use this with other lock brands?

The PH-117 is engineered for the Pinhead locking system interface. It may not mechanically mate with other brands' lock barrels, so compatibility with non-Pinhead locks is not guaranteed.

Buying Guide

When adding security accessories like a seat collar, first confirm the exact seatpost diameter and whether you already own a compatible Pinhead lock barrel. These add-on collars are the most cost-effective way to expand an existing Pinhead multi-pack to protect an additional bike without buying a whole new set. Choose collars finished to match your bike and consider powder-coating or anodized options for extra corrosion resistance if you ride in wet climates. Finally, if you have a carbon post, use a protective shim and follow recommended torque settings to avoid damage while still achieving secure locking.

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