KartDen

What actually decides lap time is whether the engine is in the right part of the powerband at the road speeds that matter. That is a tooth-count ratio problem. Pitch does not belong in that calculation. The usual mistake is trying to clone a 35 pair onto 219. A 219 setup that shares the same numerical ratio still has different sprocket diameters and a lighter chain, so it does not necessarily pull the same way. When you switch, do you take the nearest 219 combination that hits the calculated ratio, or do you expect to run it slightly different for that reason?