Chumba Stella Geometry & Bikepacking Bag Fit2026
Discontinued. Chumba no longer lists the Stella. 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.
Chumba Stella 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.
435mm chainstays, about the median for the 65 current frames here. Bottom bracket drop 51.5mm, 19mm less than the 70mm median. Chumba publishes no fork cargo mounts, and the frame publishes up to 3 bottle or accessory positions. A rear rack bolts straight on. Widest published tire 76mm 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 Chumba publishes it.
- 29 x 2.8" tires (many fit in dropout rear position on size M, L, XL)
Chumba's wording: “Max Tire Clearances: 29 x 2.4” (in all dropout positions); 29 x 2.6” (mid dropout and rearward)); 29 x 2.8" tires (many fit in dropout rear position on size M, L, XL); 27plus x 2.8" (in all dropout positions M, L, XL, mid-rearward on size small). Frame will fit 27+ x 3.0" or 29" x 3.0" on a 45mm rim”
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 | 585 | 381 | 730.25 | 90 | 607 | 398 | 435-455 | 1081-1101 | 51.5 | 70° | 73° |
| MD | 605 | 431.8 | 768.35 | 100 | 618 | 416 | 435-455 | 1101-1121 | 51.5 | 70° | 73° |
| LG | 625 | 482.6 | 800.1 | 110 | 626 | 433 | 435-455 | 1120-1140 | 51.5 | 70° | 73° |
| XL | 645 | 533.4 | 850.9 | 120 | 638 | 443 | 435-455 | 1130-1150 | 51.5 | 70.5° | 72.5° |
Bottom bracket height
Roughly 324mm off the ground. Chumba 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 — Chumba's own geometry chart: https://chumbausa.com/stella-steel-mtb-geared-singlespeed-29er-27plus — checked 2026-08-18. A dash means the figure isn't published; we leave it blank rather than estimate.
Note: Manufacturer page labels this as "Stella Steel Mountain Bike (Archived Model)" and says "Frame only, complete and partial builds available." Geometry measurements are with 29er 100mm fork; standover measured 90mm forward of bottom bracket. Seat tube length and standover were published in inches and converted to millimetres. Chumba publishes a stainless internal dropper port on the non-driveside with a rubber housing guide.
Questions people ask about this frame
Answered from what Chumba publish. Where they publish nothing, that is what it says.
Does the Stella take fork cargo cages?
Not published. Chumba don't state any fork mount provision for this frame. That isn't the same as it having none, and we won't guess from a photo.
What is the widest tyre the Stella takes?
76mm on 700c / 29in. That is the frame figure rather than the fork's, and it is what limits a loaded bike.
Will a seat pack work on the Stella?
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 625mm effective top tube and 482.6mm seat tube. 16 fit.
Read these as conservative. This size has a steeply sloping top tube — the seat tube is only 77% 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 1441 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 Chumba'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.