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20251212_Archibald bike photo-12.jpg
20251212_Archibald bike photo-13.jpg
20251212_Archibald bike photo-43.jpg

AC1 - Downhill

from CA$8,900.00

DH AC1: made for the park

Built for bike park laps and race runs, with a frame built by hand in Canada to fit you.

  • 200mm (MX) or 211mm (MX+ and full 29) rear travel with a 200mm fork

  • Pinion Smart Shift gearbox, our flagship, or the SRAM Eagle 90 derailleur build

  • Ships with a fixed seatpost. Ask about adding a dropper if you want to pedal it

  • Sizes D1 to D5, or full custom geometry for in-between riders

How to reserve: choose your size and options, then enter DEPOSIT50 at checkout to pay 50% today. After you order, we send a sizing form and confirm your fit with you before welding. The balance is due when your frame goes to welding.

Gearbox:
Shock:
Fork:
Wheelset:

DH AC1: made for the park

Built for bike park laps and race runs, with a frame built by hand in Canada to fit you.

  • 200mm (MX) or 211mm (MX+ and full 29) rear travel with a 200mm fork

  • Pinion Smart Shift gearbox, our flagship, or the SRAM Eagle 90 derailleur build

  • Ships with a fixed seatpost. Ask about adding a dropper if you want to pedal it

  • Sizes D1 to D5, or full custom geometry for in-between riders

How to reserve: choose your size and options, then enter DEPOSIT50 at checkout to pay 50% today. After you order, we send a sizing form and confirm your fit with you before welding. The balance is due when your frame goes to welding.

AC1 Custom Frame Sizing
AC1 Custom Frame Sizing
CA$1,000.00
North Shore Billet Talon Cranks North Shore Billet Talon Cranks North Shore Billet Talon Cranks
North Shore Billet Talon Cranks
CA$512.00
Color:
AC1 Belt Drive Conversion Kit
AC1 Belt Drive Conversion Kit
CA$750.00
Gates CDX Spare Belt Gates CDX Spare Belt Gates CDX Spare Belt
Gates CDX Spare Belt
CA$150.00
Size:
  • Lifetime Frame WarrantyOn every AC1 frame we build
  • Featured in PinkbikePlus NSMB, Blister and BIKE Magazin
  • Built by Hand in VancouverWelded, machined and assembled in our shop

The DH AC1 at a Glance

Built for bike park laps and race runs, sized to your body and built by hand in Canada. Pick the drivetrain and rear end that suit how you ride, and we take care of the rest.

Rear travel

200 / 211 mm

MX / MX+ and 29, with the standard 250 x 70 shock

Fork

200 mm

29 inch

Drivetrain

Pinion or Eagle 90

Smart Shift gearbox with chain or belt, or SRAM Eagle 90

Fit

D1 to D5

Or full custom geometry

“A real treat for any bike enthusiast.”

BIKE magazin, AC1 review, October 2026. Read the review

How Ordering Works

  1. Reserve your build with 50%. Use code DEPOSIT50 at checkout. Builds go in deposit order.
  2. Dial in your fit. We send a sizing form and confirm your size, travel and parts with you.
  3. Balance when welding starts. The rest is due when your frame goes to welding.
  4. Watch it come together. You get a progress update every Friday until it ships.
  5. Ride it home. We ship it to you, or pick it up at the shop in Vancouver.

Lead time for a new order is about 6 months.

Not Ready to Reserve Yet?

Send us the build you picked above with any questions, and Alex will get back to you personally.

Send My Build

Tech Specs

FrameStainless steel, high pivot, welded by hand in Canada
Rear endMX (29 front, 27.5 rear), MX+ (same wheels, longer chainstay) or full 29
Shock250 x 70 standard. Sizes 1 and 2 use a 225 x 70. More sizes in Travel and kinematics below
HeadsetZS44 upper, IS52 lower. Every AC1 ships with a silver Cane Creek Hellbender 70
Rear axle148 x 12 mm, 12 x 1.5 mm axle included
Seatpost30.9 mm, clamp included. Completes ship with a fixed seatpost. Want to pedal it? Ask us to add a dropper. A wireless dropper works best, so you can swap in a fixed post for bike park days and shuttle laps
BrakesIS rear mount with an NSB 203 mm post mount adapter. Completes use Hayes Dominion A4
CockpitCompletes include a Title cockpit
SizesD1 to D5, or custom geometry
One bike, two setupsTrail, Enduro and DH setups swap with shock hardware. Ask us to add a second set of shock plates to your order and make one bike do both.

Geometry

Pick a bike type and rear end. Only chainstay length and wheelbase change with the rear end.

MX29 front, 27.5 rear, with a 445 mm chainstay. The shortest rear end, so it’s the quickest to turn.
MX+The same mixed wheels with a longer 460 mm chainstay. It uses our 29 rear end’s kinematics, so it gets the 29 travel. More stable at speed and our pick for taller riders with a long reach.
2929 inch wheels front and rear, with a 465 mm chainstay. Great for taller riders. Shorter riders may prefer the extra clearance of a 27.5 rear wheel.

AC1 type

Rear end

Swipe sideways to see every size.

Travel, Shocks and Kinematics

Pick a rear end and a shock to see the travel, which AC1 type it suits, and how the suspension behaves through its stroke.

Rear end

MX+ and 29 share the same rear triangle kinematics, so their travel and curves match.

30%

Leverage Ratio

Millimetres of wheel travel per millimetre of shock stroke. A falling line means the bike ramps up and resists bottoming out.

The NumbersValues through the stroke and a CSV for this setup
Download Data for This Setup (CSV)
Compare All Rear EndsTravel for every shock on MX, MX+ and 29

Rear wheel travel in mm, rounded for a few setups (for example 199 to 200); the exact value is in The Numbers. Shock sizes are eye to eye x stroke. Suggested type: Trail up to 164 mm, Enduro 165 to 188 mm, DH over 188 mm. Filled tags mark our standard shock for each type. Each shock length uses its own set of shock plates, and swapping them takes 4 bolts. 250 length shocks fit frames S3 and larger; smaller frames use a 225 length shock with the same stroke and the same curves. Kinematics calculated in i-Track Suspension with the LT Link, and travel worked out at each exact shock stroke; anti-squat at a 1:1 drive ratio (24T front, 24T rear). Every shock follows the same curve, and a shorter stroke ends sooner, shown by the faded line.

Assembly Compounds

Select a compound in the table to see every place it goes.

1 1 1 3 3 3 3 3 4 4 4 1 3 4 1 3 3 3 3 1 4 4 4 4 3 3 2 3 3 2 4 1 3
CompoundApplicationCallouts
1Anti-seizeApply to surface7
2GreaseApply to surface2
3Loctite 243 (blue)Apply to threads15
4Loctite 638 (green)Bearing outer race9

Swipe sideways to see the whole drawing.

Front Triangle Torque Specifications

Fastener torque for the front triangle and gearbox mount.

6 Nm 4 mm hex 6 Nm 5 mm hex 6 Nm 4 mm hex 10 Nm 6 mm hex 10 Nm 5 mm hex 8 Nm 5 mm hex*

*When tightening the gearbox mounting bolts, tighten the side without sliding bushings first. This locates the gearbox in the frame and sets the reference for chainline.

Swipe sideways to see the whole drawing.

Rear Triangle Torque Specifications

Fastener torque for the rear triangle and seatstay pivots.

12 Nm 8 mm hex** 12 Nm 8 mm hex 8 Nm 5 mm hex 12 Nm 6 mm hex* 12 Nm 4 mm hex* 12 Nm 6 mm hex* 12 Nm 4 mm hex* 6 Nm 5 mm hex** 6 Nm 4 mm hex** 10 Nm 5 mm hex**

*When tightening the seatstay pivot bolts, hold the 4 mm side stationary and tighten to spec from the 6 mm side (non-drive side). This prevents the 4 mm bolt from stripping.

**Bolt head is accessible from the non-drive side of the bike.

Swipe sideways to see the whole drawing.

Bearings

What to order when servicing the AC1 pivots.

LocationBearingSize (ID x OD x W)Qty
Main pivotEnduro 600317 x 35 x 10 mm2
Upper rocker pivotEnduro 3801 LLU MAX12 x 21 x 8 mm2
Lower rocker pivotStandard linkEnduro DR 11197 LLU MAX BO11 x 19 x 7 mm4
Lower rocker pivotLT linkEnduro 3802 LLU MAX15 x 24 x 7 mm4
Tensioner pivotEnduro 690215 x 28 x 7 mm2
Tensioner pulleyEnduro S6000 (stainless)10 x 26 x 8 mm1
Idler pulleyEnduro 6902 Solid Lube15 x 28 x 7 mm1
Other pivot service parts
Shock eyesEnduro needle bearing kit, sized to your shock
Dropout pivotIGUS bushing (no bearing)

Full Set, Standard Link

2x 6003

2x 3801 LLU MAX

4x DR 11197 LLU MAX BO

2x 6902

1x S6000 (stainless)

1x 6902 Solid Lube

Full Set, LT Link

2x 6003

2x 3801 LLU MAX

4x 3802 LLU MAX

2x 6902

1x S6000 (stainless)

1x 6902 Solid Lube

Your link type decides which lower rocker bearing you need. Quantities are per bike.

Pinion Battery and Wiring

How the Smart Shift battery mounts and where the cables run.

  1. The battery mounts just above the gearbox on two brackets.
  2. The brackets also route the wiring into the downtube, through a large port with a rubber cover.
  3. Inside the downtube the cables run in a silicone sleeve.
  4. The shifter cable exits near the head tube.

Every Smart Shift build comes with the brackets, port cover, sleeve and photo instructions.

Ready to Build Your DH AC1?

Each tubing batch is limited and builds go in deposit order, so the sooner you reserve, the sooner you’re riding. Questions first? Email info@archibaldcycles.com.

Reserve your DH AC1