2025/2026 Homologation (Senior / Junior Chassis)
Chassis: Tony Kart · LN Kart · Kosmic · CS55 Categories: OK · TAG · KA100 · X30
1. Axle Selection
| Axle Type | Size | Track Condition | Notes |
|---|---|---|---|
| N | 1030mm | Normal | Neutral balance and mixed-grip performance |
| N | 1000mm | Normal, lots of corners | Shorter length for tight, corner-dense tracks |
| Q | 1000mm | High Grip | Adds rear-end release |
| H | 1000mm | Low Grip | Increases jack and rear grip |
2. Rear Track Width
| Track Condition | Recommended Width |
|---|---|
| Low Grip | 1385–1390 mm (pre-qualifying, cold) |
| High Grip | 1390–1398 mm (race conditions) |
| Wet Weather | Narrow as possible OTK Extended Hubs |
3. Front Track Width
| Track Condition | Hubs | Spacer Width |
|---|---|---|
| Normal | 80mm | 15 to 20mm |
| High Grip | 80mm | 15mm |
| Wet Weather | 95mm | Max Width all spacers inside |
4. Front Stub Axle (HST4)
| Track Condition | Hole | Result |
|---|---|---|
| Normal | Middle | Normal Steer |
| Normal | Outer | Calmer turn-in; reduced front-end bite |
| Wet Weather | Inner | Sharper turn-in; increased steering response |
5. Chassis Ride Height
| Rear Chassis | Front Chassis | Where To Use |
|---|---|---|
| Low | Middle | Base Setting |
| Low | High | Wet Weather |
| Low | Low | High Grip Circuit |

6. Torsion Bar Selection
| Bar Type | Grip Level | Result |
|---|---|---|
| OTK Oval | Normal / Low | Consistent, neutral flex |
| OTK Chrome | Low | Soft flex for added front compliance (Our Choice) |
| OTK Silver | Medium Grip | Balanced flex and steering response |
| OTK Gold | High Grip | Stiff flex for jack and corner release |
Note: On very low-grip surfaces (e.g., VCS), some drivers may opt to remove the front bar altogether.
7. Camber | Castor
| Track Condition | Upper Pill | Lower Pill | Toe |
|---|---|---|---|
| Normal – Standard Baseline Setup | Full Front (Neutral) | Full Front (Standard) | Neutral to 1-2mm Toe Out |
| Low grip circuits | 2mm Neg | Full Front (Standard) | 1-2mm Toe Out |
| Wet Weather | 2mm Pos | Full Rear Positive | 5-8mm Toe Out |
Effects of Toe-In (Not used often)
-
Improves straight-line stability at high speed
-
Helps the front end self-centre under bumps
-
Promotes mild inner-shoulder tyre scrub for heat-up and even wear
-
Slows initial turn-in—overuse can feel sluggish
When to use toe-in
-
Fast, sweeping tracks where stability is key
-
Bumpy street-style circuit
Starting point: +1.0 mm total toe (+1 mm per side). Adjust in 1 mm increments.
Effects of Toe-Out
-
Sharpens initial turn-in and quickens response
-
Increases front-end bite in technical sections
-
May induce slight self-steer under lean
-
Can reduce high-speed stability
When to use toe-out
-
Tight, technical circuits
-
Races prioritising agility over straight stability
-
Warm, grippy surfaces
Starting point: −2.0 mm total toe (−1 mm per side). Adjust in 1 mm increments.
Quick Setup Tips
-
Combine toe with stub-axle hole selection: aggressive hole positions amplify toe effects
-
If turn-in feels dull, reduce toe-in or add toe-out
-
If kart wanders, dial in toe-in until stable
-
Log lap times and tyre wear with each change to pinpoint your range
8. Seat Positioning
-
Front lip of seat → front of floor tray: 650 mm
-
Centre of seat rib (flat) → axle centre: 160 mm



9. Tyre Pressures
| Track Conditions | Working Rear | Others |
|---|---|---|
| Low Grip (VCS) | 11 PSI | 11.5 PSI |
| Standard | 10 PSI | 10.5 PSI |
| Wet Weather (Standing Water) | 18 PSI | 18.5 PSI |
| Very Slippery Wet | 13 PSI | 13.5 PSI |
| High Grip (AKC) | 8 PSI | 8.5 PSI |
10. Baseline Setup Overview - Where to start each weekend!
-
Chassis Ride Height: Rear low, Front middle
-
Stub Axle: Outer Hole, 1-2mm Toe Out, Neutral Caster. Starting on a completely neutral setting is advised when getting used to kart.
-
Seat: OTK seat with two seat stays brake side and adjustable seat stay, engine side. Seat position 650mm off front lip, seat level with chassis rails.
-
Torsion Bar: Flat style level or Round Chrome
- Axle: N 1030mm or twisty circuit N 1000mm
- Rear Track: 1390mm great starting Width
- Front Spacers: 15mm inside, all others outside
- Standard Wheel Hubs
- Wheels: MXJ, switch to MXC on high grip, hotter or longer races
- Tyre Pressure: 10.0 PSI Working, 10.5 PSI All others (LH03 Leconte)
