Co-op Cycles ADV 3.1 Geometry & Bikepacking Bag Fit2026
Discontinued. Co-op Cycles no longer lists the ADV 3.1. It's here because these frames stay in circulation second-hand and the geometry is still what you need to pick bags — but you won't find one new.
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.
445mm chainstays, 10mm longer than the 435mm median across the 65 current frames here. The fork publishes cargo mounts, and the frame publishes bottle or accessory mounts. A rear rack bolts straight on.
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 Co-op Cycles publishes it.
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 | 515 | 390 | 709 | — | 532 | 367.5 | 445 | 1043.6 | — | 70° | 74.5° |
| S | 525 | 430 | 733.9 | — | 536.7 | 371.1 | 445 | 1049 | — | 70° | 74° |
| M | 545 | 470 | 768.4 | — | 567 | 377 | 445 | 1050.1 | — | 71° | 73.5° |
| L | 560 | 510 | 799.4 | — | 588.7 | 380 | 445 | 1060.6 | — | 71° | 73° |
| XL | 580 | 550 | 843 | — | 631.3 | 387 | 445 | 1082.5 | — | 71° | 73° |
Source — Co-op Cycles's own geometry chart: https://www.rei.com/product/122463/co-op-cycles-adv-31-bike?redirect-pup=false — checked 2026-08-18. A dash means the figure isn't published; we leave it blank rather than estimate.
Note: REI's Co-op Cycles product page currently says this product is not available. The page publishes wheel size as 650b, returned as 27.5in to match the allowed enum. REI does not publish max tire clearance, head tube length, or bottom bracket drop in this chart; those fields are null. All geometry measurements are stated by REI in millimeters or degrees.
Questions people ask about this frame
Answered from what Co-op Cycles publish. Where they publish nothing, that is what it says.
Does the ADV 3.1 take fork cargo cages?
Rack mounts, not cage mounts. The fork mounts Co-op Cycles publish are for racks or fenders, and a lowrider eyelet won't take a cargo cage. That doesn't rule cages out — it means nobody has said.
What is the widest tyre the ADV 3.1 takes?
Not published in a form we can read. Co-op Cycles don't publish a maximum tyre width for this frame.
Will a seat pack work on the ADV 3.1?
Not published. Co-op Cycles 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 545mm effective top tube and 470mm seat tube. 16 fit.
Frame bag fit is calculated from Co-op Cycles'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.