Genesis Longitude 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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Genesis Longitude 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.
458mm chainstays, 23mm longer than the 435mm median across the 65 current frames here. Bottom bracket drop 70mm, close to the 70mm median. The fork publishes cargo mounts, and the frame publishes up to 3 bottle or accessory positions. Genesis states the frame does not take a rear rack. Widest published tire 76mm on 650b / 27.5in, 61mm 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 Genesis publishes it.
Genesis's wording: “MAX TYRE SIZE: 27.5X3.0/29X2.4”
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 |
|---|---|---|---|---|---|---|---|---|---|---|---|
| SM | 582 | 406 | 766 | 125 | 614 | 395 | 458 | 1105 | 70 | 68° | 71° |
| MD | 610 | 445 | 787 | 135 | 626 | 420 | 458 | 1134 | 70 | 68° | 71° |
| LG | 638 | 480 | 806 | 145 | 637 | 445 | 458 | 1149 | 70 | 68° | 71° |
| XL | 663 | 520 | 837 | 160 | 643 | 465 | 458 | 1188 | 70 | 68° | 71° |
Bottom bracket height
Roughly 301mm off the ground. Genesis 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 — Genesis's own geometry chart: https://www.genesisbikes.co.uk/genesis-longitude-vargn21530 — checked 2026-08-18. A dash means the figure isn't published; we leave it blank rather than estimate.
Note: Geometry values are already in millimetres and degrees. Genesis' own page is JavaScript-rendered in search/open results, but the published manufacturer chart is cross-referenced to this Genesis URL by Bike Insights and current retailer listings for product code GN22530/VARGN21530. Price is GBP. Genesis publishes one seat-angle row, “Frame Seat Angle”, at 71 degrees on every size. That is the actual angle; the top-tube identity needs the effective one, which works out near 73.3 and Genesis does not publish it. The chart is stored as Genesis prints it. Price is GBP.
How the Longitude 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 Genesis publish. Where they publish nothing, that is what it says.
Does the Longitude take fork cargo cages?
Yes. Genesis 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 Longitude takes?
76mm on 650b / 27.5in. Across the wheel sizes Genesis publish: 61mm on 700c / 29in, 76mm 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 Longitude?
Not published. Genesis 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 638mm effective top tube and 480mm seat tube. 16 fit.
Read these as conservative. This size has a steeply sloping top tube — the seat tube is only 75% of the effective top tube. Bag makers publish a minimum seat tube length assuming a roughly level top tube, so on a frame like this the comparison understates how much room you actually have. The front triangle here is about 1508 cm², which is the number that actually decides what fits. Several bags marked unlikely below will physically fit. Half-frame bags don't depend on seat tube length at all.
Frame bag fit is calculated from Genesis'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.