Tailfin CargoPack Alloy vs Topeak BackLoader X 15L
Two seat packs, measured against each other on the figures that decide whether they work on a bike.
The short answer
The CargoPack Alloy takes capacity; the BackLoader X 15L takes how far it reaches back, weight, price and value per litre. The biggest single gap is $290 between them. 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
3L more in the CargoPack AlloyThe 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
4cm shorter on the BackLoader X 15LLength 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.
Weight
524g lighter on the BackLoader X 15LEmpty 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
$290 between themManufacturer's price as we hold it.
Per litre
$14.66 per litre between themPrice divided by the maker's capacity. A crude measure that still catches the case where the dearer bag is also the bigger one, which the price alone hides.
Side by side
Including the rows where they are level.
| Tailfin CargoPack Alloy | Topeak BackLoader X 15L | |
|---|---|---|
| Capacity | 18L | 15L |
| Reach behind the saddle | 55cm | 51cm |
| Depth | 24cm | 24cm |
| Weight | 1129g | 605g |
| Price | $420 | $130 |
| Per litre | $23.33 | $8.67 |
We may earn a commission if you buy through this link, at no extra cost to you.
We may earn a commission if you buy through this link, at no extra cost to you.