# 2940 Dunbier R2174 Mackay Soft Poly Dog Bone Keel Roller 12" with Insert | Marine Trailer Part

🔧 Product Description

  

Dunbier Soft-Poly Dogbone Keel Roller 12 Inch with Insert - Part Number: 2940

  

A soft poly dogbone keel roller for boat-trailer keel and hull-support systems. The 12" / 305mm roller is designed to provide controlled hull support and smooth movement during launch and retrieval while matching the specified pin and bracket system.

  

⚙️ Key Features

  

• soft poly construction

• dogbone keel profile supports and guides the hull

• Nominal roller size: 12" / 305mm

• Designed for repeated immersion and boat-trailer launch/retrieve cycles

• Replaceable independently of a serviceable bracket or roller rail

• Reinforced with a reinforcing internal insert

  

📏 Specifications

  

• Nominal size: 12" / 305mm

• Approximate dimensions: 305 × 65 × 95mm

• Centre bore: approximately 24.5mm

• Recommended matching roller pin: Dunbier 3040, approximately 360 × 24.5mm

• Material/profile: soft poly, dogbone keel

  

🔄 Cross Reference & Related Parts

  

• Dunbier: 2940

• Mackay: R2174

  

🚤 Trailer Compatibility & Application

  

• Suitable for larger fibreglass and painted hulls requiring a wide soft support surface

• Bracket width, roller-pin diameter and installed clearance must match the existing trailer

• The roller should contact a structurally supported hull area rather than fittings, strakes or unsupported panels

• Roller shape and firmness should be matched to the hull material and keel profile

  

🔌 Function

  

Supports the boat during storage and road transport while allowing the hull to roll over the trailer during launching and retrieval. The shaped profile also helps maintain centreline alignment.

  

Common signs of wear or replacement:

  

• Roller is cracked, split, flattened or permanently distorted

• Material has hardened, softened excessively or become UV-damaged

• Centre bore is elongated and allows the roller to wobble

• Roller no longer turns freely on the pin

• Hull develops marks because the roller surface is damaged or contaminated

  

🛠️ Installation & Safety

  

• Support the boat safely before removing any load-bearing roller

• Use the specified pin diameter with suitable washers and retaining hardware

• Align the roller so the hull load is centred across the profile

• Confirm free rotation without excessive side movement

• Recheck all roller heights and hull support after replacement

  

📦 Condition

  

• Brand new Dunbier Marine Products trailer component

• Supplied as one 12" / 305mm soft poly roller

• Supplied in original or equivalent packaging

## Details

- **Price:** 45.5 AUD
- **Vendor:** Dunbier
- **Tags:** Dunbier Boat Trailers | Marine Trailer Parts & Accessories

## Variants

| Variant | Price | Available |
|---------|-------|-----------|
| Default Title | 45.50 AUD | In stock |

## Images

- 2940 Dunbier R2174 Mackay Soft Poly Dog Bone Keel Roller 12" with Insert | Marine Trailer Part

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> Source: [Sawley's Auto and Marine](https://www.sawleysautoandmarine.com.au/products/2940-dunbier-soft-poly-dog-bone-keel-roller-12-with-insert-mackay-r2174)
> Updated: 2026-08-05