# 3100SQ Dunbier Rolla-Matic Double 20mm Square Leg | Marine Trailer Part

🔧 Product Description

  

Dunbier Double Rolla-Matic Assembly with 20mm Square Leg - Part Number: 3100SQ

  

A galvanised Dunbier Rolla-Matic hull-support assembly fitted with two grey wobble rollers. The pivoting roller arms follow the hull surface and distribute weight across multiple contact points while allowing the boat to roll during launch and retrieval.

  

⚙️ Key Features

  

• Includes two grey plastic wobble rollers

• Galvanised pivoting support assembly

• approximately 150mm double-arm support

• Two-way articulation allows the rollers to conform to the hull

• Includes 20mm square support leg

  

📏 Specifications

  

• Roller quantity: two

• Support leg: 20mm square tube

• Approximate roller-arm span: approximately 150mm double-arm support

• Replacement standard grey roller: Dunbier 2969

• Mounting clamp must match the trailer cross member

  

🔄 Cross Reference & Related Parts

  

• Dunbier: 3100SQ

• 20mm-leg double assembly: Dunbier 3100SQ

• 40mm-leg double assembly: Dunbier 3100

• No-leg double assembly: Dunbier 3102

• Wide double assembly: Dunbier 3103

• Quad assembly: Dunbier 3110

  

🚤 Trailer Compatibility & Application

  

• Suitable for Dunbier Rolla-Matic, Supa-Rolla and compatible trailer support systems

• Roller hardness and position must suit the hull material and shape

• Use the correct Dunbier mount for 50 × 50, 76 × 50 or 102 × 50mm cross members

  

🔌 Function

  

Supports the lower hull on multiple pivoting rollers, allowing the assembly to equalise load as the hull shape and angle change.

  

Common signs of wear or replacement:

  

• Pivot arms seize or have excessive play

• Rollers are cracked, flat-spotted or worn

• Support leg is bent

• Assembly no longer shares load evenly

• Mounting clamp moves on the cross member

  

🛠️ Installation & Safety

  

• Support the boat before loosening the assembly

• Set both sides to equal height and angle

• Keep rollers clear of chines, strakes and fittings

• Tighten pivot and clamp hardware while preserving intended articulation

• Recheck hull support after launching and retrieving the boat

  

📦 Condition

  

• Brand new Dunbier Marine Products trailer component

• Supplied as one complete Rolla-Matic assembly with support leg

• Supplied in original or equivalent packaging

## Details

- **Price:** 71.0 AUD
- **Vendor:** Dunbier
- **Tags:** Dunbier Boat Trailers | Marine Trailer Parts & Accessories

## Variants

| Variant | Price | Available |
|---------|-------|-----------|
| Default Title | 71.00 AUD | In stock |

## Images

- 3100SQ Dunbier Rolla-Matic Double 20mm Square Leg | Marine Trailer Part
- 3100SQ Dunbier Rolla-Matic Double 20mm Square Leg | Marine Trailer Part
- 3100SQ Dunbier Rolla-Matic Double 20mm Square Leg | Marine Trailer Part
- 3100SQ Dunbier Rolla-Matic Double 20mm Square Leg | Marine Trailer Part

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> Source: [Sawley's Auto and Marine](https://www.sawleysautoandmarine.com.au/products/3100sq-dunbier-rolla-matic-double-20mm-square-leg)
> Updated: 2026-08-05