Crust Bombora FramesetGeometry & Bikepacking Bag Fit2026
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 66 current frames here. Bottom bracket drop 64mm, 6mm less than the 70mm median. Crust publishes no fork cargo mounts, and no frame bottle positions are published. Crust states the frame does not take a rear rack. Widest published tire 58mm on 650b / 27.5in, 48mm 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 Crust publishes it.
Crust's wording: “Designed around a 650b/ 27.5" Wheel with a 2.3" max tire size. If you want to run it 700c, your max clearance will be a 48mm tire.”
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 | 520 | 456 | 747 | 121 | 540 | 365 | 425 | 1008 | 64 | 69.5° | 74.5° |
| Small | 540 | 502 | 775 | 132 | 553 | 378 | 425 | 1020 | 64 | 70° | 74° |
| Medium | 560 | 543 | 804 | 153 | 576 | 382 | 425 | 1023 | 64 | 71° | 73° |
| Large | 580 | 574 | 832 | 177 | 599 | 395 | 425 | 1043 | 64 | 71° | 73° |
| XL | 600 | 629 | 872 | 208 | 628 | 406 | 425 | 1064 | 64 | 71° | 73° |
| XXL | 620 | 670 | 907 | 241 | 660 | 416 | — | 1085 | 64 | 71° | 73° |
Bottom bracket height
Roughly 307mm off the ground. Crustdoesn'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 — Crust's own geometry chart: https://crustbikes.com/collections/all/products/bombora — checked 2026-08-18. A dash means the figure isn't published; we leave it blank rather than estimate.
Note: Crust does not state a model year on the product page; modelYear is set to 2026 for the current manufacturer page. Geometry chart is metric millimeters. Current product size selector lists XS through XL, but the manufacturer's geometry chart also publishes XXL; XXL chainstay is blank in the chart and returned null. Sold as a frameset; priceFrom is the frameset price, not a complete bike.
Which frame bags fit
Every frame bag we track, checked against this frame's published geometry. Pick your size.
Checking 19 frame bags against a 580mm effective top tube and 574mm seat tube. 19 fit.
Frame bag fit is calculated from Crust'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.