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AC1 - Trail
- 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 Trail AC1 at a Glance
One frame for everything you ride, sized to your body and built by hand in Canada. Pick the drivetrain and wheel setup that suit how you ride, and we take care of the rest.
Rear travel
150 / 160 mm
MX / full 29, with the standard 210 x 50 shock
Fork
160 to 170 mm
29 inch
Drivetrain
Pinion or Eagle 90
Smart Shift gearbox with chain or belt, or SRAM Eagle 90
Fit
T1 to T5
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 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.
Tech Specs
| Frame | Stainless steel, high pivot, welded by hand in Canada |
|---|---|
| Wheels | Full 29, or MX (29 front, 27.5 rear) |
| Shock | 210 x 50 standard. 210 x 55 also fits (see Travel and kinematics below) |
| Headset | ZS44 upper, IS52 lower. Every AC1 ships with a silver Cane Creek Hellbender 70 |
| Rear axle | 148 x 12 mm, 12 x 1.5 mm axle included |
| Seatpost | 30.9 mm, clamp included. Completes ship with a OneUp dropper |
| Brakes | IS rear mount with an NSB 203 mm post mount adapter. Completes use Hayes Dominion A4 |
| Cockpit | Completes include a Title cockpit |
| Sizes | T1 to T5, 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, 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.
Leverage Ratio
Millimetres of wheel travel per millimetre of shock stroke. A falling line means the bike ramps up and resists bottoming out.
Anti-Squat
Pedalling support. Above 100% the rear resists bobbing when you pedal.
Anti-Rise
Braking behaviour. Near 100% the rear holds its height under braking; lower keeps it more active.
Axle Path
How far the rear axle moves back as the wheel moves up, which helps it roll over square hits.
The NumbersValues through the stroke and a CSV for this setup
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.
| Compound | Application | Callouts | |
|---|---|---|---|
| 1 | Anti-seize | Apply to surface | 7 |
| 2 | Grease | Apply to surface | 2 |
| 3 | Loctite 243 (blue) | Apply to threads | 15 |
| 4 | Loctite 638 (green) | Bearing outer race | 9 |
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 Trail 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.