Poseidon X vs Surly Straggler 650b

Both published charts held against each other, on the specs that decide what the bike carries.

The short answer

The X takes price; the Straggler 650b takes tire clearance. Which matters more is your route, not a scoreboard.

Assembled from the differences below rather than written over them, so it cannot drift from the table. Every figure is the manufacturer's; nobody here has ridden either bike.

Where they differ

5 of the 6 things we can compare come out differently. The rest are close enough not to decide anything.

Widest published tire

5mm more on the Straggler 650b on 700c / 29in
Poseidon X
45mm on 700c / 29in
Surly Straggler 650b
50mm on 700c / 29in, 50mm on 650b / 27.5in

The frame figure, not the fork's — forks are routinely cut for more rubber than the rear triangle, and compared only on a wheel size both frames publish. Loaded, tire width is also seat-pack clearance: a big tire and a sagging pack compete for the same space.

Rear rack

only the Straggler 650b publishes a rear rack answer
Poseidon X
Not published
Surly Straggler 650b
Bolts straight on

Read from each maker's own mount wording. An adapter is a real cost the price tag does not mention, and 'not published' is not the same as no — it just is not something to buy a rack on.

Fork cargo mounts

only the Straggler 650b publishes somewhere to bolt a cage
Poseidon X
None published
Surly Straggler 650b
Published

Cage mounts on the fork blades. This moves weight low and off the bars, which is where a heavy bar roll does the most to the steering. A frame with none published may still have them — it means the maker does not say.

Chainstay

19mm longer on the X
Poseidon X
425mm
Surly Straggler 650b
406mm

The gap between seat tube and rear axle, which a rack, panniers and your heels all share. Longer is more room for a load; shorter is a more compact bike. Which you want is a preference, not a winner.

From

$699.01 between them
Poseidon X
$999.99
Surly Straggler 650b
$1,699

Manufacturer's cheapest complete build. Every spec above belongs to the frame and does not change between builds of the same model, so the cheapest build of the right frame is usually the right answer.

Side by side

Including the rows where the two are level, because a spec that doesn't separate them is still a spec you might be checking.

Poseidon XSurly Straggler 650b
Widest published tire45mm on 700c / 29in50mm on 700c / 29in, 50mm on 650b / 27.5in
Rear rackNot publishedBolts straight on
Fork cargo mountsNone publishedPublished
Frame bottle positions4not published as a count
Chainstay425mm406mm
From$999.99$1,699
Sizes56
FrameAluminum4130 Chromoly steel

Drawn to scale

Largest published size of each, built from the charts rather than illustrated. The front triangle is the part that decides frame bag fit.

Surly Straggler 650b — 54cm. Front triangle ≈ 1454 cm² · effective top tube 565mm · seat tube 540mm
Surly Straggler 650b in size 54cm, drawn to scale from Surly's published geometry. The shaded area is the front triangle — roughly 1454 cm² of space for a frame bag. Wheels are indicative; frame lines are accurate.
Poseidon
X
$999.99 · 5 sizes
Full geometry and which bags fit →
Surly
Straggler 650b
$1,699 · 6 sizes
Full geometry and which bags fit →

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