I bought a new Triumph Sprint ST a year ago. Right from the start, I have had problems getting a smooth, slick downchange, especially from fourth to third to second and first. Occasionally I get it right, but most of the time it sticks and I have to release the clutch slightly, then crunch through the gears. I contacted Triumph’s warranty department, and was told that the clutch may be “sticking” and it would need stripping and cleaning and re-assembly.
John Dean, email
I’m surprised the dealer who sold you the bike hasn’t got onto this yet under warranty. There is a simple visual check you can do to start with. Each time you change gear the gearlever should return to its original position. If not, it could simply be a sticky gear linkage that needs freeing up and lubricating. The other possible cause is also lubrication-related, but this time it’s internal. A few years ago Triumph had a run of bikes with these symptoms and they traced it back to the assembly line.
When the engines are being built moly grease is used in the gearbox along with engine oil. The input shaft is hollow and provides a pressurised oil feed to the clutch. If too much grease is used or it gets onto the inside of the input shaft it ends up on the clutch plates, gumming them together. Usually this can be cleaned off, but if they have become contaminated they will need replacing. While the mechanic is in there, they can inspect another possible cause, the detent springs that are behind the clutch basket.