Blackburn Outpost Seat Pack with Drybag vs Revelate Designs Terrapin System 14L

Two seat packs, measured against each other on the figures that decide whether they work on a bike.

The short answer

The Outpost Seat Pack with Drybag takes weight, price and value per litre; the Terrapin System 14L takes capacity, how far it reaches back and tire clearance. 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

6 of the 6 things we can measure come out differently.

Capacity

3L more in the Terrapin System 14L
Blackburn Outpost Seat Pack with Drybag
11L
Revelate Designs Terrapin System 14L
14L

The 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

6cm shorter on the Terrapin System 14L
Blackburn Outpost Seat Pack with Drybag
52cm
Revelate Designs Terrapin System 14L
46cm

Length 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

2cm shallower on the Terrapin System 14L
Blackburn Outpost Seat Pack with Drybag
22cm
Revelate Designs Terrapin System 14L
20cm

Depth 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

117g lighter on the Outpost Seat Pack with Drybag
Blackburn Outpost Seat Pack with Drybag
450g
Revelate Designs Terrapin System 14L
567g

Empty 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

$139 between them
Blackburn Outpost Seat Pack with Drybag
$80
Revelate Designs Terrapin System 14L
$219

Manufacturer's price as we hold it.

Per litre

$8.37 per litre between them
Blackburn Outpost Seat Pack with Drybag
$7.27
Revelate Designs Terrapin System 14L
$15.64

Price 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.

Blackburn Outpost Seat Pack with DrybagRevelate Designs Terrapin System 14L
Capacity11L14L
Reach behind the saddle52cm46cm
Depth22cm20cm
Weight450g567g
Price$80$219
Per litre$7.27$15.64
Blackburn
Outpost Seat Pack with Drybag
$80 · 450g
Revelate Designs
Terrapin System 14L
$219 · 567g

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