Apidura Backcountry Dropper Post Adapter
The Apidura Backcountry Dropper Post Adapter lets you run a saddle pack on a dropper post: it limits post travel to keep clearance between bag and wheel, and prevents damage to the post or the bag. It comes in two versions – MTB (50 g, with shims for 30.9, 31.6 and 34.9 mm posts) and Gravel (46 g, for 27.2 mm posts) – and installs in minutes with a 3 mm hex key.
Why a dropper post adapter – and why this one
A dropper post and a saddle pack do not normally get along: when the post drops, the bag can hit the rear tyre, and straps clamped directly on the stanchion can damage the post. The Backcountry Dropper Post Adapter solves this:
- The bag stays clear of the wheel. The adapter limits dropper post travel, so the saddle pack keeps its clearance even when the suspension is compressed.
- Your dropper post is protected. The saddle pack strap sits on the adapter instead of the stanchion.
- The pack stays stable on rough terrain. A flat rear section and a ridged strap retainer hold the bag securely.
- It fits your bike. The MTB version includes shims for common mountain bike dropper posts, and the Gravel version is made for 27.2 mm posts.
Who is it for?
- Mountain bikers and bikepackers who want to carry a saddle pack without giving up their dropper post.
- Gravel riders with a 27.2 mm dropper post.
- Backcountry Saddle Pack owners – and riders of any other bag that uses a 25 mm seat post strap.
Which version? Choose MTB for mountain bike dropper posts of 30.9 mm, 31.6 mm or 34.9 mm diameter (shims included). Choose Gravel for 27.2 mm dropper posts. If you are not sure which size applies to your bike, consult your bike manufacturer.
Key features
Quick and secure attachment
Attaches to dropper posts using a 3 mm hex key.
Choice of shims for the MTB adapter
Shims adapt the MTB version to different dropper post diameters.
Helps maintain clearance
Limits dropper post travel to maintain clearance for saddle packs under compression.
Compatible with 25 mm straps
Works with the Backcountry Saddle Pack, which uses a single 25 mm post strap.
Specifications
| MTB (PDA) | Gravel (PDS) | |
|---|---|---|
| Width | 4.5 cm | |
| Dropper post diameter | 30.9 mm, 31.6 mm, 34.9 mm (shims included) | 27.2 mm |
| Attachment | 3 mm hex head screw | |
| Manufacturing process | Injection-moulded glass fibre-reinforced nylon | 3D-printed nylon |
| Compatible straps | 25 mm seat post straps (e.g. Backcountry Saddle Pack) | |
Frequently asked questions
Which version do I need?
The MTB version fits mountain bike dropper posts of 30.9 mm, 31.6 mm or 34.9 mm diameter using the included shims. The Gravel version fits 27.2 mm dropper posts. If you are unsure of your post diameter, consult your bike manufacturer.
Which saddle packs does it work with?
It is designed for seamless integration with the Backcountry Saddle Pack and works with any other bag that uses a 25 mm seat post strap.
How is it installed?
It attaches to the dropper post with a 3 mm hex head screw – all you need is a 3 mm hex key.
Will I lose dropper travel?
Yes, partly – that is the purpose of the adapter. It limits dropper post travel so the saddle pack keeps clearance from the rear wheel when the suspension is compressed.
About Apidura
Founded in 2013, Apidura designs bikepacking bags for long-distance and ultra-endurance riding, tested by riders on events such as the Transcontinental Race and the Tour Divide. The range is built around three families: the fully waterproof Expedition series for touring and all-weather bikepacking, the lightweight Racing series for ultra-distance racing, and the rugged Backcountry series for off-road trails.
Every Apidura product comes with a 3-year producer guarantee from the date of purchase, covering the entire product. After that, Apidura can support at-home repair or recommend a trusted repairer.