Weather Helm on IOR Ranger 37 - Rudder Modifications?

I am a little late to this post but here goes anyway.... sorry this got a bit long

I have a Ranger 37. In stock form when the wind picked up they were known to have a heavy weather helm and control issues. An unbalanced rudder that was entirely too small is a large part of this problem. The fix, which takes care of the problem quite nicely is a much larger, balanced or semi balanced rudder. More rudder area helps significantly with control, and balanced rudder takes pressure off the helm. Mull designed a bigger rudder when the problem was identified (not unique to Rangers BTW). Almost every boat at this point has a much larger rudder than the original version . A quick and dirty modification is to add area on the lower section of the rudder ahead of the rudder post and also extend the rudder down deeper by adding some new structure to the existing rudder.

I did my quick modification in two days in the yard after work. The rudder stayed in the boat. The best (but more expensive) way is to replace it with a Schumacker rudder from the folks at Foss foam in Florida or from Phils Foils for around $1K-ish. Also, FYI the Skeg on a Ranger 37 is not at all structural or needed to support the existing rudder post. You can cut it off with a chainsaw right now and remove the lower bearing and it will have no effect of the strength of the remaining rudder. It is held on by 4 small bolts under the cockpit. Mull himself suggested this modification. Removing the skeg will make up for the extra surface area of the bigger rudder with a net result of less wetted surface. That skeg was a great idea in theory but in reality is not helping matters or preventing a spinout like you instinctively think it should. There is a reason no one uses skegs like this anymore.

Downwind the boat tracks better and no longer wants to spin out when over pressed. I would replace the Ranger 37 rudder with the same rudder size they use to replace the Cal 40 rudders. I believe the rudder used on the very similar designed Catalina 38 is better than the Original R37 rudder but is still far too small. IMO too big a rudder is much better than too small for these boats, especially offshore. The new rudder will be lighter, higher aspect, a thinner profile for less drag, and far less prone to stalling and cavitation. Probably lose 300 lbs or so out of the back of the boat with the 47 year old waterlogged rudder and skeg gone.

On my boat I went quick and dirty and deepened my rudder and added some area forward. Significant handling benefit, the boat is simply more under control. I am happy with my modded rudder which helped a ton but still want the Schumacker rudder and skeg delete.

Gonzo's advice about the smaller headsail to balance the rig is correct and useful, unlike some of the advice on the thread (no offense). An overlapping genoa has a lot of Center of Effort behind the mast so again counterintuitively, a smaller headsail will remove some weather helm on a big overlapping boat like this. You lose drive in light air, but it's heavy air where the helm becomes an issue. With my modded rudder and running a 90% jib (small headsail for doublehanding with my kid) my rudder feel is almost dead (ie no weather helm and no lee helm) in 6-7 knots or less of wind, but if it picks up the feel is almost perfect and I can put the boat anywhere I want to without a fight, even with my blown-out garbage dacron sails, which cause lots of heeling and weather helm when the wind picks up.

Another tip. I did a half circumnavigation on a Cascade 36. That boat had a great balanced rudder without a skeg, and running downwind in the trades (for days and days) you need a reef in the main to have the boat track well under wind vane self steering. In 15-20 knot trades it does not hurt your speed and makes life easy. Racing is another matter.