Seat Pack Ultra WP

The biggest problem with seat packs is bag wag. EVOC fights it two ways. First, reinforced side panels help the bag hold its shape. Second, it anchors at two points: a wedge that shoehorns around your seat post, and straps that run under the saddle. Between them, the bag stays put instead of swinging side to side, even loaded. The heavier you pack it, the harder the weight presses into the wedge, locking it tighter.

Everything inside stays dry under the adjustable waterproof roll-top. Reflective strips and a rear light strap keep you visible after dark. Elastic loops on the outside hold whatever doesn't fit in: a shed jacket, wet socks, a stuff sack.

It clears a dropper post. Run the 4L for overnighters and fast, light setups, or the 7L when you want to carry more without stepping up to the bigger BOA bags.

• Buckle closure, not dials. Fewer parts, less weight. Built for racing.
• Reinforced side panels hold the bag's shape and cut wag as it empties.
• Adjustable waterproof roll-top.
• Reflective strips and a rear light strap for visibility after dark.
• Elastic exterior loops for gear that doesn't fit inside.
• Compatible with dropper posts.
• Two-point mount. A seat post wedge plus under-saddle straps lock the bag at two points to stop side-to-side wag.
• Load-activated hold. The more you pack, the harder the weight presses into the wedge, tightening the bag down.
• Two sizes: 4L and 7L.

Seat Pack Ultra WP 4L 

• Volume: 4 L
• Weight: 290 g
• Dimensions: 6.7 x 11.8 x 5.9 in (17 x 30 x 15 cm)

Seat Pack Ultra WP 7L 

• Volume: 7 L
• Weight: 360 g
• Dimensions: 6.7 x 16.5 x 5.9 in (17 x 42 x 15 cm)

Both sizes 

• Material: Waterproof, PFAS-free fabric
• Closure: Adjustable waterproof roll-top, buckle
• Mount: Seat post wedge + under-saddle straps (dropper compatible)

Ultra or BOA, what's the difference?

The Ultra closes with buckles to save weight and is built for racing, in 4L and 7L. The BOA line uses quick-adjust dials, loads and unloads faster, and runs to bigger sizes (9, 12, and 15L). Same anti-wag mount on both. Pick Ultra for fast and light, BOA for capacity and convenience.

4L or 7L, which should I get?

Go 4L for overnighters and minimalist, fast setups. Go 7L when you're carrying more for longer days or multi-day trips and don't want to move up to the BOA bags.

Does it work with a dropper post?

Yes, both sizes are dropper compatible. Clearance depends on your frame and how far your post drops, so cycle the dropper to full bottom-out and check the bag clears your tire before your first ride.

Can I mount a tail light?

Yes. There's a dedicated rear light strap, plus reflective strips front and back.