Timbuk2 Never Check Expandable Backpack vs. Tom Bihn Synapse 25

Two carry-on travel backpacks, compared spec for spec.

Timbuk2 Never Check Expandable Backpack

Front facing view of the Timbuk2 Never Check Expandable Backpack
Capacity25 L
Weight1.2 kg
Dimensions48×29×15 cm
Airline fit93%
Price$210

Feature by feature

Timbuk2 Never Check Expandable BackpackFeatureTom Bihn Synapse 25
Storage
2 Compression N
28L Expanded Capacity None
0 Opening 0
front Passport front
N Passthrough N
Carry
Y Backpack Y
N Hip Belt removable
removable Sternum Strap removable
Inside
15in Laptop 15in
3 Main Compartments 6
Y Organizer Y
Outside
× Hard Shell ×
N Rain-fly N
1, side Water Bottle Holder 1, front
Y Water Resistant Y
Material
200 denier Halcyon/nylon ripstop fabric lining 400 denier nylon lower back

Tom Bihn Synapse 25

Front facing view of the Tom Bihn Synapse 25
Capacity25 L
Weight0.8 kg
Dimensions51×34×23 cm
Airline fit71%
Price$250

Key differences between the Timbuk2 Never Check Expandable Backpack and Tom Bihn Synapse 25

Both have: passport pocket, backpack straps, sternum strap, laptop sleeve, built-in organizer, water resistant.

Which airlines take each bag as a carry-on

We checked both bags against the carry-on size limits of 189 airlines. 134 accept both. 41 accept only the Timbuk2 Never Check Expandable Backpack, and 0 accept only the Tom Bihn Synapse 25.

Only the Timbuk2 Never Check Expandable Backpack fits

Air Baltic, Air China, Air Malta, Air Niugini, Air Serbia, Air Seychelles, Asiana Airlines, ATA Airlines, Belavia, Blue Air, Bulgaria Air, China Eastern, Emirates Airlines, Enter Air, Etihad Airways, flybe, Icelandair, InselAir, Juneyao Airlines, Liat Airlines, Luxair, Meridiana Fly, Nordwind Airlines, Pakistan International, Qatar Airways, Regional Express, Royal Brunei Airlines, Ryanair, S7, Shandong Airlines, Shenzhen Airlines, Sun Express, TAP Air Portugal, TAROM, Tianjin Airlines (A320 & E190), TUI, Ukraine International, VIM Airlines (Closed), Virgin Australia, Volotea, Xiamen.

Timbuk2 Never Check Expandable Backpack vs. Tom Bihn Synapse 25: which should you pack?

The Timbuk2 Never Check Expandable Backpack carries the same capacity as the Tom Bihn Synapse 25 (25L vs. 25L), while the Tom Bihn Synapse 25 is the lighter pack at 0.8kg (vs. 1.2kg). For carry-on flexibility, the Timbuk2 Never Check Expandable Backpack fits 93% of the airlines we track — the higher of the two. If you prioritise packing volume, choose the Timbuk2 Never Check Expandable Backpack; if you want to travel lighter, the Tom Bihn Synapse 25 is the better call.