From a different type of rider to cyclopathic with the standard gearing I'd normally change into sixth around 90 to 95 KPH. You can ride around at 80 KPH in sixth but the bike is a lot happier in fifth at that speed. I went the other way with gearing by adding a tooth to the front sprocket. The case protector will not fit with this sprocket. After a couple of thousand kays I reverted back to the standard gearing. The bike lost its spark with the one tooth bigger front sprocket. I rarely ever rev the bike harder than a guestimated 6000 rpm. In this country they like to book you at anything 3 KPH above the speed limit and I'm to old to be a boy racer these days. The rear sprocket on the T model has two less teeth.