Bombtrack Hook EXT Geometry & Bikepacking Bag Fit2026
The same page we read this geometry from. We don't hold live pricing or stock for frames, so check both there.
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Bombtrack Hook EXT frame geometry, drawn to scale
Every tube angle and length below is from the published chart, not an illustration. The front triangle area is the number that decides which frame bags fit — and it changes a lot across sizes.
What this frame gives a loaded bike
Chainstay length is the gap between the seat tube and the rear axle, which a rack, panniers and your heels all have to share. Bottom bracket drop is how far the cranks sit below the axles. Both are compared against the median across every current frame we hold.
425mm chainstays, 10mm shorter than the 435mm median across the 65 current frames here. Bottom bracket drop 70-75mm, close to the 70mm median. The fork publishes cargo mounts, and the frame publishes bottle or accessory mounts. A rear rack bolts straight on. Widest published tire 52mm on 650b / 27.5in, 40mm on 700c / 29in.
Every figure above is the manufacturer's, computed against the rest of the database. It says what the frame allows, not how it feels — nobody here has ridden it.
What it can carry
Mount provision and clearance, as Bombtrack publishes it.
Bombtrack's wording: “Frame max tire clearance w/o fender: 52-584 / 40-622; Fork max tire clearance w/o fender: 57-584 / 57-622”
Geometry
All figures in millimeters except angles. Effective top tube and seat tube are the two that decide frame bag fit.
| Size | Eff. top tube | Seat tube | Standover | Head tube | Stack | Reach | Chainstay | Wheelbase | BB drop | Head angle | Seat angle |
|---|---|---|---|---|---|---|---|---|---|---|---|
| XS | 519 | 460 | 748 | 110 | 554 | 365 | 425 | 995 | 75 | 71.5° | 74.5° |
| S | 533 | 500 | 776 | 130 | 573 | 374 | 425 | 1010 | 75 | 71.5° | 74.5° |
| M | 556 | 530 | 803 | 150 | 589 | 387 | 425 | 1025 | 70 | 72° | 74° |
| L | 570 | 570 | 831 | 170 | 608 | 396 | 425 | 1040 | 70 | 72° | 74° |
| XL | 595 | 600 | 855 | 190 | 627 | 409 | 425 | 1060 | 70 | 72° | 74° |
Bottom bracket height
Roughly 296–301mm off the ground. Bombtrack doesn't publish this directly — we derive it from their BB drop and a typical 74.2cm tire diameter, so treat it as indicative rather than exact. It changes with the tire you fit. Lower means more stable and more pedal strikes; higher means the opposite.
Source — Bombtrack's own geometry chart: https://bombtrack.com/products/bombtrack-hook-ext-frameset — checked 2026-08-18. A dash means the figure isn't published; we leave it blank rather than estimate.
Note: Manufacturer's current product page found for the Hook EXT frameset; complete-bike geometry is also published on Bombtrack's Hook EXT page with the same geometry values. Price not published on the sourced manufacturer page.
How the Hook EXT compares
Against the frames people actually cross-shop it with — both charts held together, on the specs that decide what the bike carries.
Questions people ask about this frame
Answered from what Bombtrack publish. Where they publish nothing, that is what it says.
Does the Hook EXT take fork cargo cages?
Yes. Bombtrack publish cargo-cage mounts on the fork, but the wording does not give a count we can stand behind, so we're not going to put a number on it.
What is the widest tyre the Hook EXT takes?
52mm on 650b / 27.5in. Across the wheel sizes Bombtrack publish: 40mm on 700c / 29in, 52mm on 650b / 27.5in. Those are frame figures, not the fork's — forks are routinely cut for more rubber than the rear triangle.
Will a seat pack work on the Hook EXT?
Not published. Bombtrack don't state dropper compatibility for this frame, so we can't tell you whether a dropper would compete with a seat pack on it.
Which frame bags fit
Every frame bag we track, checked against this frame's published geometry. Pick your size.
Checking 16 frame bags against a 556mm effective top tube and 530mm seat tube. 16 fit.
Frame bag fit is calculated from Bombtrack's published geometry, so it's as reliable as their chart. Seat packs and handlebar rolls depend on your exposed seatpost and bar width, which no geometry table lists — the bag finder covers those once you add your own measurements.