Topeak MTX TrunkBag Rear Bicycle Bag - Spacious, QuickTrack Mounting

In this review the Topeak MTX TrunkBag is presented as a practical rear bag for cyclists who need dependable everyday storage without fuss. The single biggest reason to buy is its combination of a large, organized 16.6 L capacity and QuickTrack mounting compatibility that lets the bag snap on and off a rack quickly while remaining stable on the road. The reviewer finds it especially useful for commuters and tourers who want a weather-resistant shape that protects gear and reduces road vibration thanks to the rigid EVA foam construction.

Key Features

• Large 16.6 L Storage: A divided main compartment and dual expandable pannier side panels provide ample room for clothing, tools, and a 6-pack or daily commuting gear.
• Durable, Water-Repellent Build: The 600 denier polyester shell and rigid EVA foam keep the bag's shape while repelling moisture and absorbing road vibration to protect contents.
• QuickTrack Compatibility: Designed to attach securely to MTX QuickTrack racks for fast mounting and release, making on-bike use straightforward and tool-free.
• Convenient Carrying Options: Integrated shoulder strap and carrying handle make it useful off the bike for errands or short walks to the office.
• Visibility and Practical Extras: Elastic top bungees, a rear bottle holder, 3M reflective strip and safety light clip add practical storage and improved visibility for commuting.

Who It's For

The Topeak MTX TrunkBag suits daily commuters, light tourers and riders who want a roomy, well-constructed rear bag that attaches and detaches quickly. Riders who carry a change of clothes, tools, a lunch or small groceries will appreciate the divided layout and expandable pannier side panels.

It is less appropriate for riders who need full waterproofing for heavy rain or who prefer a low-profile saddlebag; the material is water-repellent rather than fully waterproof, and the bag is designed to sit on an MTX-compatible rack rather than replace panniers for heavy touring loads.

Pros & Cons

Pros

• Roomy 16.6 L capacity with expandable side panels provides flexible storage for a variety of rides.
• Sturdy construction and rigid EVA foam maintain shape and reduce vibration transmitted to gear.
• QuickTrack attachment system makes mounting and removal fast and secure on compatible racks.
• Useful commuter features such as a bottle holder, shoulder strap and reflective strip increase practicality and safety.

Cons

• Not fully waterproof in heavy downpours, so wet-weather riders may need extra protection or a rain cover.
• Requires an MTX QuickTrack rack or MTX Dual Side Frames for some BeamRack setups, so additional hardware may be necessary.

Specifications

Brand	Topeak
Capacity	16.6 L
Material	600 denier polyester with rigid EVA foam
Mounting	MTX QuickTrack compatible (MTX Dual Side Frames for BeamRacks)
Features	Expandable pannier panels, rear bottle holder, shoulder strap, handle, elastic top bungees
Visibility	3M reflective strip and safety light clip

Our Verdict

The Topeak MTX TrunkBag is a solid value for commuters and day tourers who want a roomy, well-built rear bag that mounts quickly to MTX racks. Its durable, water-repellent shell and rigid foam core protect contents and reduce vibration, while the QuickTrack system and carrying options make it practical both on and off the bike.

Frequently Asked Questions

Will this attach to any rack?
It attaches to MTX QuickTrack racks; MTX Dual Side Frames are required for some BeamRack setups.

Is the bag waterproof?
The fabric is water-repellent and the foam helps protect contents, but it is not fully waterproof in heavy rain without an additional rain cover.

How much can it hold?
It offers 16.6 L of storage with expandable pannier panels and a divided main compartment suitable for clothes, tools and daily gear.