The short version
- Check compatibility before buying
- Prefer simple, durable fittings
- Do not obstruct lights or moving parts
- Inspect after the first few rides
Start with the rack interface
Some trunk bags use hook-and-loop straps while others need a proprietary plate or rail. Check the required deck width, rail spacing and clearance above the tyre before buying the bag or adapter.
The combined load must stay within both rack and bag limits. Secure every strap end and confirm the rear light remains visible from directly behind.
Pack for stable handling
Place dense items low and avoid a tall, loose stack that can sway. A rack-top bag puts weight higher than a pannier, so add load gradually and test starts, turns and braking in a quiet place.
Remove the bag or use a lockable arrangement when leaving the bicycle; a quick-release mount designed for convenience is not normally theft protection.
Check the current guidance
Rules, schemes and product ranges can change. These live links are the authoritative or independent starting points used for this guide.
