Oveja Negra Gearjammer Seatpack vs Tailfin Alloy Seat Pack
Two seat packs, measured against each other on the figures that decide whether they work on a bike.
The short answer
The Gearjammer Seatpack takes how far it reaches back, tire clearance, weight and price; the Alloy Seat Pack takes capacity. Which of those you care about depends on the frame you are fitting it to.
Assembled from the differences below rather than written over them. Every figure is a published measurement or computed from one — nobody here has used either one.
Where they differ
5 of the 6 things we can measure come out differently.
Capacity
5L more in the Alloy Seat PackThe maker's own figure. Worth reading alongside the dimensions below rather than on its own — two bags of the same litreage can want very different frames.
Reach behind the saddle
11cm shorter on the Gearjammer SeatpackLength is the lever arm on the seatpost, and the longer lever is what makes a loaded pack sway. Shorter is easier to live with; longer usually means more volume. It is a trade, not a fault.
Depth
6cm shallower on the Gearjammer SeatpackDepth is what competes with the rear tire once the pack sags under load. On a small frame or a big tire this is the measurement that decides it.
Weight
180g lighter on the Gearjammer SeatpackEmpty weight as published. Worth holding against capacity rather than alone — the lighter bag is not the better one if it carries a third less.
Price
$70 between themManufacturer's price as we hold it.
Side by side
Including the rows where they are level.
| Oveja Negra Gearjammer Seatpack | Tailfin Alloy Seat Pack | |
|---|---|---|
| Capacity | 15L | 20L |
| Reach behind the saddle | 44cm | 55cm |
| Depth | 18cm | 24cm |
| Weight | 340g | 520g |
| Price | $155 | $225 |
| Per litre | $10.33 | $11.25 |