Topeak MTX TrunkBag Rear Bicycle Bag - Spacious 8L Storage

Our review of the Topeak MTX TrunkBag finds it a solid choice for commuters and day riders who need organized, secure rear-rack storage without fuss. The single biggest reason to buy is its practical 8L layout combined with a rugged, water-resistant build that keeps gear protected and easy to access. For someone who wants a bag that slides on and off a QuickTrack rack, holds a change of clothes or a 6-pack, and adds useful extras like a water bottle holder and reflective trim, this trunk bag delivers reliable everyday performance.

Key Features

• Versatile 8L Storage: The main compartment is divided and paired with two mesh side pockets so items stay organized for commuting or short trips.
• Durable & Water-Resistant Build: Rugged 600 denier polyester and EVA foam panels give structure and protection against light weather and impacts.
• Hydration Ready Design: An integrated rear water bottle holder keeps a bottle within reach on longer rides without needing extra cages.
• QuickTrack System Compatible: The slide-and-click attachment mounts securely to Topeak MTX QuickTrack racks for fast removal and reattachment.
• Added Safety & Convenience: Includes a shoulder strap, carry handle, top bungees, 3M reflective strip and a safety light clip for visibility and multiway carrying.

Who It's For

The Topeak MTX TrunkBag is ideal for daily commuters, errand riders and weekend day trippers who use a compatible rear rack and want a mid-sized bag that balances capacity with compactness. It works well for anyone who values a bag that detaches quickly and also serves off-bike with a shoulder strap and handle.

Riders who need very large expedition luggage or waterproof dry-bag protection for multi-day tours should look elsewhere, since this bag is built for commuter and day-ride utility with water resistance rather than full submersion-level sealing.

Pros & Cons

Pros

• Well organized 8L capacity with divided main compartment and mesh pockets for easy access and separation of items.
• Sturdy construction from 600 denier polyester and EVA foam panels provides structure and protection for contents.
• QuickTrack mounting offers dependable attachment and simple removal for mixed bike and off-bike use.
• Accessories like the bottle holder, reflective strip and safety light clip add practical convenience and visibility.

Cons

• Not fully waterproof; the water-resistant fabric and optional rain cover are good for light weather but not for extended exposure to heavy rain.
• Capacity is useful but limited to day rides and commuting rather than extended bikepacking loads.

Specifications

Brand	Topeak
Capacity	8L (divided main compartment)
Material	600 denier polyester with EVA foam panels
Mounting	Topeak MTX QuickTrack compatible
Extras	Rear bottle holder, shoulder strap, carry handle, top bungees
Safety	3M reflective strip and safety light clip

Our Verdict

The Topeak MTX TrunkBag is a practical, well-built rear bag for riders who need secure, quick-to-remove storage for commuting and short trips. It balances organized 8L capacity with durable materials and useful extras, making it good value for riders who use MTX racks and want a reliable everyday trunk bag.

Frequently Asked Questions

Will this bag stay secure on a rear rack?
The QuickTrack slide-and-click system keeps the bag stable on compatible Topeak MTX racks and customers report it feels secure during typical commuting rides.

Is the bag waterproof?
The construction is water-resistant with EVA panels and there is an optional rain cover for heavier weather, but it is not fully waterproof for extended heavy rain or submersion.

Can I carry the bag off the bike?
Yes, it includes a shoulder strap and carry handle so it functions as a convenient grab-and-go bag off the bike.