Tiller extension spare parts keep the tiller extension used for steering the rudder in working order without replacing the entire part. Harken's range includes an extension attachment fitting (H7101) and a joint (H7102), which connect the extension to the rudder itself and allow the extension to rotate during use. In addition, the range includes a separate tiller lock and a wide range of Spinlock EA/EJ series spare parts: a complete spare parts kit, a holder, a mounting fitting with a locking pin and a regular mounting fitting.
The joint is the most critical moving part of the extension surface, as it wears out the most during use and its play increases over time, which can cause inaccuracy in rudder control, especially in racing, where precise feel is important. The mounting bracket, in turn, connects the joint to the surface itself, and its wear or loosening can cause the entire extension surface to come off during use — a significant safety detail.
Spinlock's EA/EJ series parts are compatible specifically with Spinlock's own extension surfaces, while Harken's parts fit Harken's own system — parts from different brands are usually not cross-compatible, so it is important to identify the correct manufacturer's spare part before ordering.
Wear on the extension joint is often first seen as increased play, which is felt as inaccuracy in rudder control — this should be taken seriously at an early stage, as a badly worn joint can suddenly fail completely just when precise steering is most important, for example when turning in strong winds. The mounting bracket and joint must be compatible parts from the same manufacturer — Harken and Spinlock systems are not cross-interchangeable, so it is a good idea to check with the manufacturer of your extension before ordering if you are unsure. Spinlock’s EA/EJ series complete spare parts kit is a cost-effective choice if several parts have worn out at the same time, rather than ordering individual parts one after the other. The surface lock, which holds the extension in the desired position without constant manual holding, is particularly useful during autopilot or wind instrument use, when the rudder does not need to be moved continuously by hand.
It is worth checking the condition of the extension surface parts before each competition season, as a small gap can grow into a significant problem surprisingly quickly.
The availability of spare parts for both manufacturers makes maintenance easier, even if the boat has extension surfaces of different ages and different brands in use.
Timely replacement of spare parts before a visible defect occurs prevents unexpected problems, especially in a competitive situation, when precise control is most important.
