Image 1 of 3
Image 2 of 3
Image 3 of 3
AC1 Frame Kit
The AC1 Frame Kit at a glance
Build your AC1 your way. One stainless frame that runs as a Trail, Enduro or DH bike, sized to you and built by hand in Canada. Bring your own parts or add ours.
Setups
Trail, Enduro, DH
One frame, swap the shock hardware
Rear travel
150 to 222 mm
Set by rear end and shock (see Travel below)
Drivetrain
Gearbox or derailleur
Pinion Smart Shift, Effigear, or a standard crankset with the BB carrier
Fit
Sizes 1 to 5
Or full custom geometry
“The Archibald formula is dialled.”
NSMB, AC1 Trail review, April 2026. Read the review
How ordering works
- Reserve your build with 50%. Use code DEPOSIT50 at checkout. Builds go in deposit order.
- Dial in your fit. We send a sizing form and confirm your size, travel and parts with you.
- Balance when welding starts. The rest is due when your frame goes to welding.
- Watch it come together. You get a progress update every Friday until it ships.
- Ride it home. We ship it to you, or pick it up at the shop in Vancouver.
Lead time is typically 5 to 6 months.
Tech specs
| Frame | Stainless steel, high pivot, welded by hand in Canada |
|---|---|
| Included | Frame, silver Cane Creek Hellbender 70 headset, seat clamp and shock plates |
| Add-ons | Rear shock, gearbox, or the BB carrier. The carrier bolts into the gearbox mount and gives a threaded T47 shell for a standard crankset, so the frame stays ready for a gearbox later |
| Rear end | MX (29 front, 27.5 rear), MX+ or full 29 |
| Shock | Trail 210 x 50. Enduro 230 x 57.5 on MX, 210 x 55 on MX+ and 29. DH 250 x 70 (225 x 70 on sizes 1 and 2) |
| Headset | ZS44 upper, IS52 lower |
| Rear axle | 148 x 12 mm, 12 x 1.5 mm axle included |
| Seatpost | 30.9 mm, clamp included |
| Brakes | IS rear mount with an NSB 203 mm post mount adapter |
| Sizes | Sizes 1 to 5 in Trail, Enduro or DH geometry, or custom geometry |
| One bike, two setups | Trail, 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.
AC1 type
Rear end
Swipe sideways to see every size.
Travel and shock options
Pick your rear end to see the rear travel each shock gives and which AC1 type it suits.
Rear end
All rear ends
| Shock | MX | MX+ | 29 |
|---|
Rear wheel travel in mm. 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: Trail 210 x 50; Enduro 230 x 57.5 on MX, 210 x 55 on MX+ and 29; DH 250 x 70 (225 x 70 below S3). 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 the 225 length shock with the same stroke.
Assembly compounds
Select a compound in the table to see every place it goes.
| Compound | Application | Callouts | |
|---|---|---|---|
| 1 | Anti-seize | Apply to surface | 10 |
| 2 | Grease | Apply to surface | 6 |
| 3 | Loctite 243 (blue) | Apply to threads | 15 |
| 4 | Loctite 638 (green) | Apply to surface | 2 |
Swipe sideways to see the whole drawing.
Front triangle torque specifications
Fastener torque for the front triangle and gearbox mount.
*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.
*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.
| Location | Bearing | Size (ID x OD x W) | Qty |
|---|---|---|---|
| Main pivot | Enduro 6003 | 17 x 35 x 10 mm | 2 |
| Upper rocker pivot | Enduro 3801 LLU MAX | 12 x 21 x 8 mm | 2 |
| Lower rocker pivotStandard link | Enduro DR 11197 LLU MAX BO | 11 x 19 x 7 mm | 4 |
| Lower rocker pivotLT link | Enduro 3802 LLU MAX | 15 x 24 x 7 mm | 4 |
| Tensioner pivot | Enduro 6902 | 15 x 28 x 7 mm | 2 |
| Tensioner pulley | Enduro S6000 (stainless) | 10 x 26 x 8 mm | 1 |
| Idler pulley | Enduro 6902 Solid Lube | 15 x 28 x 7 mm | 1 |
| Other pivot service parts | |||
| Shock eyes | Enduro needle bearing kit, sized to your shock | ||
| Dropout pivot | IGUS 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.
- The battery mounts just above the gearbox on two brackets.
- The brackets also route the wiring into the downtube, through a large port with a rubber cover.
- Inside the downtube the cables run in a silicone sleeve.
- 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 AC1 Frame Kit?
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.