Surly

Surly Karate Monkey Geometry & Bikepacking Bag Fit

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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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Frame
4130 Chromoly, Natch tubing, double-butted main triangle
Wheel size
27.5 x 3.0" design; also 29 x 2.5" max
Max tire
3.0in (650b / 27.5in)
From
$1,849
Sizes
5

Surly Karate Monkey 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.

Surly Karate Monkey — X-Small. Front triangle ≈ 883 cm² · effective top tube 560mm · seat tube 330mm
Surly Karate Monkey in size X-Small, drawn to scale from Surly's published geometry. The shaded area is the front triangle — roughly 883 cm² of space for a frame bag. Wheels are indicative; frame lines are accurate.
Surly Karate Monkey — Small. Front triangle ≈ 1029 cm² · effective top tube 585mm · seat tube 368mm
Surly Karate Monkey in size Small, drawn to scale from Surly's published geometry. The shaded area is the front triangle — roughly 1029 cm² of space for a frame bag. Wheels are indicative; frame lines are accurate.
Surly Karate Monkey — Medium. Front triangle ≈ 1221 cm² · effective top tube 610mm · seat tube 419mm
Surly Karate Monkey in size Medium, drawn to scale from Surly's published geometry. The shaded area is the front triangle — roughly 1221 cm² of space for a frame bag. Wheels are indicative; frame lines are accurate.
Surly Karate Monkey — Large. Front triangle ≈ 1428 cm² · effective top tube 635mm · seat tube 470mm
Surly Karate Monkey in size Large, drawn to scale from Surly's published geometry. The shaded area is the front triangle — roughly 1428 cm² of space for a frame bag. Wheels are indicative; frame lines are accurate.
Surly Karate Monkey — X-Large. Front triangle ≈ 1644 cm² · effective top tube 660mm · seat tube 521mm
Surly Karate Monkey in size X-Large, drawn to scale from Surly's published geometry. The shaded area is the front triangle — roughly 1644 cm² of space for a frame bag. Wheels are indicative; frame lines are accurate.

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.

423mm chainstays, 12mm shorter than the 435mm median across the 65 current frames here. Bottom bracket drop 55mm, 15mm less than the 70mm median. The fork publishes cargo mounts, and the frame publishes up to 3 bottle or accessory positions. Surly publishes no rear rack answer, which is not the same as no — but it is not something to buy a rack on. Widest published tire 76mm on 650b / 27.5in, 64mm 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 Surly publishes it.

Fork mounts
2 Three-Pack mounts
Bottle mounts
1 standard + 1 Three-Pack on XS-M; 2 standard + 1 Three-Pack on L-XL
Rack & fender
Rear fender mounts; rack and top-tube bag bosses not stated in source
Max tire clearance
64mm on 700c / 29in76mm on 650b / 27.5in

Surly's wording: “29 x 2.5" or 27.5 x 3.0"”

Dropper post
Compatible

Builds

As Surly lists them. Prices are MSRP at our last check and move around — treat them as a reference point, not a live quote.

BuildDrivetrainMSRP
Karate Monkey - Snow Mold WhiteShimano Deore 12-speed$1,849
Karate Monkey - Fools' GoldShimano Deore 12-speed$1,849
Karate Monkey - Organic EggplantShimano Deore 12-speed$1,849
Karate Monkey Front Suspension - Lost at Sea BlueShimano Deore XT 12-speed$2,599
Karate Monkey Front Suspension - Peach Salmon SundaeShimano Deore XT 12-speed$2,599

Geometry

All figures in millimeters except angles. Effective top tube and seat tube are the two that decide frame bag fit.

SizeEff. top tubeSeat tubeStandoverHead tubeStackReachChainstayWheelbaseBB dropHead angleSeat angle
X-Small56033074310059737742310535569°73°
Small58536875910059740242310785569°73°
Medium61041978310059742742311035569°73°
Large63547081211060645042311295569°73°
X-Large66052182712061547242311555569°73°

Bottom bracket height

Roughly 316mm off the ground. Surly 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 — Surly's own geometry chart: https://surlybikes.com/products/karate-monkey-frameset-organic-eggplant — checked 2026-08-16. A dash means the figure isn't published; we leave it blank rather than estimate.

Note: Surly marks this source page as a legacy bike/frame model.

How the Karate Monkey 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 Surly publish. Where they publish nothing, that is what it says.

Does the Karate Monkey take fork cargo cages?

Yes — 2 cages. Surly publish cargo-cage mounts on the fork, one set per leg.

What is the widest tyre the Karate Monkey takes?

76mm on 650b / 27.5in. Across the wheel sizes Surly publish: 64mm 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 Karate Monkey?

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 610mm effective top tube and 419mm seat tube. 13 fit.

Read these as conservative. This size has a steeply sloping top tube — the seat tube is only 69% 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 1221 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.

Excellent fit
Revelate Designs Joey Downtube Bag 1L

Plenty of room in frame triangle

$75
108g
Excellent fit
Revelate Designs Joey Downtube Bag 2L

Plenty of room in frame triangle

$75
136g
Excellent fit
Apidura Backcountry Frame Pack 1L

Plenty of room in frame triangle

$81
100g
Excellent fit
Topeak MidLoader 6L

Plenty of room in frame triangle

$93
337g
Excellent fit
Ortlieb Frame-Pack Toptube 3L

Plenty of room in frame triangle

$165
170g
Excellent fit
Apidura Expedition Frame Pack 3.8L

Plenty of room in frame triangle

$168
244g
Excellent fit
Ortlieb Frame-Pack Toptube 4L

Plenty of room in frame triangle

$170
200g
Good fit
Oveja Negra Superwedgie 2.0 Frame Bag

Good fit within frame triangle

$120
198g
Good fit
Rockgeist Half Frame Bag

Good fit within frame triangle

$190
170g
Tight
Topeak MidLoader 4.5L

Tight fit against seat tube length

$78
195g
Tight
Blackburn Outpost Frame Bag Medium

Tight fit against seat tube length

$80
280g
Tight
Apidura Racing Frame Pack

Tight fit against seat tube length

$151
145g
Tight
Ortlieb Frame-Pack RC

Tight fit against seat tube length

$165
221g
Unlikely
Moosetreks Full Frame Bag

Seat tube likely too short (need 45cm, you have 41.9cm)

$60
300g
Unlikely
Revelate Designs Ranger Frame Bag

Seat tube likely too short (need 44cm, you have 41.9cm)

$155
340g
Unlikely
Apidura Expedition Full Frame Pack

Seat tube likely too short (need 46cm, you have 41.9cm)

$232
358g

Frame bag fit is calculated from Surly'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.