Revelate Designs ECOPAK Shrew Seat Bag vs Topeak BackLoader 10L
Two seat packs, measured against each other on the figures that decide whether they work on a bike.
The short answer
The Revelate Designs ECOPAK Shrew Seat Bag is ahead on how far it reaches back, tire clearance and weight. Nothing measured here goes the other way.
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
3 of the 4 things we can measure come out differently.
Reach behind the saddle
18.2cm shorter on the ECOPAK Shrew Seat BagLength 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
11.8cm shallower on the ECOPAK Shrew Seat BagDepth 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
288g lighter on the ECOPAK Shrew Seat BagEmpty weight as published. Worth holding against capacity rather than alone — the lighter bag is not the better one if it carries a third less.
Side by side
Including the rows where they are level.
| Revelate Designs ECOPAK Shrew Seat Bag | Topeak BackLoader 10L | |
|---|---|---|
| Reach behind the saddle | 31.8cm | 50cm |
| Depth | 10.2cm | 22cm |
| Weight | 142g | 430g |
| Price | $79 | $70 |