Fairlight Secan Geometry & Bikepacking Bag Fit2026
The only link we hold for this frame is the geometry document itself, which is not a page you can buy from.
Fairlight Secan 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.
432mm chainstays, about the median for the 65 current frames here. Bottom bracket drop 75-77mm, 6mm more than 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 62mm on 650b / 27.5in, 53mm on 700c / 29in. It takes a dropper post.
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 Fairlight publishes it.
Fitting fenders costs 7mm of that.
- Max measured width: 1x setup – 700 x 53mm, 650 x 62mm / 2x setup - 700 x 48mm, 650 x 58mm
- Max measured width with guards: 1x setup – 700 x 47mm, 650 x 55mm / 2x setup - 700 x 45mm, 650 x 50mm
Fairlight's wording: “Max measured width: 1x setup – 700 x 53mm, 650 x 62mm / 2x setup - 700 x 48mm, 650 x 58mm Max measured width with guards: 1x setup – 700 x 47mm, 650 x 55mm / 2x setup - 700 x 45mm, 650 x 50mm”
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 |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 51R | 537 | 490 | 756 | 104 | 540 | 380 | 432 | 1027 | 77 | 70° | 74° |
| 51T | 535 | 495 | 771 | 136 | 570 | 370 | 432 | 1028 | 77 | 70° | 74° |
| 54R | 550 | 510 | 775 | 121 | 558 | 388 | 432 | 1036 | 77 | 70.5° | 74° |
| 54T | 549 | 515 | 791 | 155 | 590 | 378 | 432 | 1038 | 77 | 70.5° | 74° |
| 56R | 568 | 520 | 789 | 139 | 576 | 396 | 432 | 1044 | 75 | 71.25° | 73.5° |
| 56T | 568 | 535 | 812 | 175 | 610 | 386 | 432 | 1046 | 75 | 71.25° | 73.5° |
| 58R | 581 | 540 | 808 | 156 | 594 | 404 | 432 | 1053 | 75 | 71.75° | 73.5° |
| 58T | 581 | 555 | 832 | 194 | 630 | 394 | 432 | 1055 | 75 | 71.75° | 73.5° |
| 61R | 594 | 560 | 827 | 175 | 612 | 412 | 432 | 1067 | 75 | 71.75° | 73.5° |
| 61T | 595 | 575 | 851 | 215 | 650 | 402 | 432 | 1070 | 75 | 71.75° | 73.5° |
Bottom bracket height
Roughly 298–300mm off the ground. Fairlight doesn't publish this directly — we derive it from their BB drop and a typical 75cm 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 — Fairlight's own geometry chart: https://media.fairlightcycles.com/wp-content/uploads/2025/08/Fairlight-Frame-Geometries-2025-v1.pdf — checked 2026-08-18. A dash means the figure isn't published; we leave it blank rather than estimate.
Note: Geometry source is Fairlight Frame Geometries, 2025 models only, v1.0, updated 29/8/25. Secan 3.0 remains the current Secan model on Fairlight's site. Geometry standover is published as: Standover height (with 700x45 tyre) - @ 65mm forward of BB centre. Technical details source page: https://fairlightcycles.com/secan-3-0/
How the Secan 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 Fairlight publish. Where they publish nothing, that is what it says.
Does the Secan take fork cargo cages?
Yes. Fairlight 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 Secan takes?
62mm on 650b / 27.5in. Across the wheel sizes Fairlight publish: 53mm on 700c / 29in, 62mm 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 Secan?
The dropper is the problem, not the pack. This frame publishes dropper routing, and a dropper and a seat pack want the same space — fitting one rules out almost every strap-on seat pack and leaves rail-mounted bags at a fraction of the volume. Run a rack or a saddle-rail bag if you want both.
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 568mm effective top tube and 535mm seat tube. 16 fit.
Frame bag fit is calculated from Fairlight'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.