Choose a sprocket for a new track

You're racing a circuit for the first time and have no gearing notes for it. Gear too short and you'll hit the limiter before the end of the longest straight. Gear too long and the kart bogs out of the slow corners. Gear Strategy gives you a sensible rear sprocket to start with, based on the track's layout, your engine and your experience. The free Pit Kit calculators then show what one tooth either way would do.

Before you start

• A Premium or Pro with AI plan for Gear Strategy. The calculators work on every plan.
• Your kart and a saved setup in your profile, with the engine set. Without it you'll see "Gearing unavailable".
• An active session at the new track. In the Sessions tab, tap your session under PLANNED SESSIONS.
• Your class gearing rules to hand. Some classes fix or limit the sprockets you can run.

Get the recommendation

1. With the session active, open the Intelligence tab.
2. Check the DRIVER EXPERIENCE card first. Choose your level from Experience level and tap Apply. Be honest. When two sprockets are closely matched, a higher level can tip the choice one tooth longer, and a lower level one tooth shorter.
3. Tap Gear Strategy. The screen is headed Gear Strategy Ranking.
4. Read the RECOMMENDED card:
   • Sprocket: the rear sprocket to fit.
   • Gear ratio: the ratio that sprocket gives with your front sprocket.
   • Theoretical top speed: in your chosen speed unit.
   • Driver experience, Track type and Technical score: the context the choice was made in.
5. Read the sentence under it. It tells you how your experience affected the choice. For example, it may say two options were closely matched and the shorter one was chosen, or that the circuit's own demands decided it.

If you see "Set the engine on your kart to get a gearing recommendation", add the engine to your kart on the web portal under Setups, then come back.

Reading the result

• TRACK ANALYSIS: how the circuit was read. It covers Track type, Technical score, Longest straight, Direction changes, Slow corners, Straight count, Acceleration demand and Top speed demand. A tight, twisty track with lots of slow corners pushes towards shorter gearing. A long straight pushes towards longer gearing.
• STRATEGY OPTIONS: the other sprockets considered. Each has a Confidence figure and a Vs best figure, and the top pick carries the RECOMMENDED chip. If the next option is close, it's a good back-up to try in practice.
• SELECTION REASONING: why this sprocket won, in plain words.

Good to know: This is advice only, and it does not change your saved setup. Always check the sprocket against your class regulations before you fit it. The choice is yours.

See what one tooth either way does (any plan)

1. On Home, tap the PIT KIT card.
2. Under Calculators, tap Gear Ratio.
3. Enter your Front teeth, Rear teeth, Tyre diameter (mm) and Peak RPM.
4. Read the Ratio, the Rollout (per wheel rev) and the theoretical speed at your peak RPM.
5. Look at the One tooth either way cards. They show what you gain with one tooth more (more drive) or one tooth fewer (more top end).

If you've logged sprockets in Spares Inventory, they appear under Rear sprockets you own. Tap one to try it.

Tip: The theoretical speed ignores drag, slip and the clutch. Use it to compare gearings, not as a speedo.

Check the chain still fits

A bigger change of sprocket can need a different chain.

1. In the Pit Kit, under Calculators, tap Chain Length.
2. Enter Front teeth, Rear teeth and Centre distance (mm). Measure the centre distance from sprocket centre to sprocket centre, with the engine in the middle of its slots.
3. Choose the Chain pitch. #219 is the karting standard.
4. Read Chain to buy / make. It's rounded up to an even number of links, because chains join in even links. Take up the slack with the engine position.

Going further: extreme gearing

If you want to see gearing outside the normal range, tap the person icon on Home, then Driver. Under ADVANCED, turn on Extreme Gearing Analysis and tap Save profile. Gear Strategy then adds a second card with a Speed extreme and an Acceleration extreme. It shows the potential benefit and the compromise for each, and a note on whether they're within your class rules. Your normal recommendation does not change.

Tip: After the session, note how the kart pulled on the longest straight in your debrief notes. If it hit the limiter early, try one tooth fewer next time.

Do it on the web portal

1. In the left sidebar, open Race Engineering > Intelligence and choose your session.
2. Find the Gear Strategy Ranking tile on the engineering page.

To experiment, open Race Engineering > Lab. It's a what-if playground: try different gearing on the Gear tab, turn on Compare Mode to see the change against your current setup, and use Reset to baseline to start again. Nothing you try in the Lab is saved.