How do I adjust mast rake and rig tension on a Bavaria 37 Cruiser?
My Bavaria 37 Cruiser develops quite heavy weather helm close-hauled, and the leeward shrouds look loose when the breeze picks up. How should I check the mast rake and adjust the rig tension without putting too much load into it?
Answer
Centre the mast athwartships, set a slight aft rake with the forestay length, then tension the shrouds evenly and check the result under sail. On a Bavaria 37 Cruiser, aim for light weather helm, controlled forestay sag and a fair mast curve, with tension and pre-bend set to suit the fitted spar and mainsail system.
Check the rig specification
Bavaria used different rig packages across model years, while replacement spars or standing rigging can change the requirements. Confirm the mast manufacturer, mainsail type (conventional or in-mast furling) and wire diameters before choosing tension settings. Advice for another 37-footer may not apply.
With the boat afloat in sheltered water, remove unusual bow or stern loads and inspect:
- Chainplates and their supporting structure for movement, cracking or water staining.
- The mast heel and deck support for displacement or compression.
- Shroud terminals, spreader roots and turnbuckles for cracks, corrosion, damaged threads or broken wire strands.
- The forestay attachment and furler connections, including concealed fittings where accessible.
Stop if you find structural movement or damaged terminals. More tension will compound the problem. Keep every stay attached and supported throughout adjustment, and have a rigger handle any forestay disconnection.
Centre the mast and measure rake
Start with the backstay adjuster eased and enough shroud tension to support the mast securely. Hoist a steel tape on the main halyard and compare distances to matching points on the port and starboard chainplates. Adjust the cap shrouds until the measurements agree, then sight up the mast track for sideways bends.
Measure rake separately. In still conditions, hang a weight from the main halyard just above the deck. Measure its horizontal distance aft of the mast at a recorded height. Keep the halyard clear of the boom and fittings, and record the boat's loading so you can repeat the measurement.
No single millimetre setting suits every Bavaria 37 Cruiser. Start with the spar maker's figure or the existing documented setting. If neither is available, establish slight aft rake and refine it under sail.
Forestay length sets the basic rake: lengthening normally increases aft rake; shortening reduces it. The backstay primarily changes rig loading, mast bend and forestay sag. If the forestay adjustment is concealed within the furler, follow the furler's instructions or use a rigger.
Tension the shrouds in stages
Use a rig tension gauge matched to the wire diameter and construction. A Loos or Seldén gauge is useful, but convert its scale reading using the correct table.