Bow roller clearance?

[Tsunami]

I have a question for those who have added a bow roller to their trailer. When loading the boat onto the trailer, this addition helps to bring the bow right up to the winch bowstop without the need to perform the "Mac bump."

As I understand it the hull should only contact the roller as it is guided up onto the forwardmost V bunk. When securely loaded the hull is supported completely by the V bunk and the roller is free of the hull by a certain distance.

An adjustable height roller would be handy but beyond my capabilities to build. This job will be tough enough as it is because I will be doing it with the boat on the trailer.

Could those of you that have done this in the past give me an idea as to the distance between the hull and roller when the boat is fully forward to the bowstop?

Thanks in advance.
Dean

[closehaul]

Tsunami, I have a 2000 26X on a 2008 26M Alum trailer and added a roller behind the forward V as you plan to do. In answer to your question: I placed the roller in contact with the hull (but not carrying any load) when I installed. The roller will not eliminate the need to do the Mac Bump but does enable the boat to roll up into the V instead of ramming into it. Also avoids hitting the trailer rails by slightly lifting the bow during final trailer landing. One thing I learned that may be helpful: most rollers are designed or 1/2" or 5/8" mtg bolt. This is pretty wimpy when the support spread is a couple feet. I used a larger roller with nylon bushings on ends (can't remember where I got it but is similar to the Attwood link). The white bushings can be knocked out enabling use of a larger axle. Used some PVC tubing sleeves to center the roller on the axle. The attachment bolts on trailer rails are near the neutral axis so did not reduce strength of rails or cause a stress riser. The larger axle design eliminates the need to build structure between trailer rails to support a conventional roller.

[closehaul]

Tsunami, Attached is good explanation of the Mac Bump by Tomfoolery. The 'fall back' is actually a safety feature to keep from tearing the winch off the tower or worse, the bow eye out of the hull. To experience the geometry in reverse I once accidently left the winch tight when launching and the strap became so tight I thought something would fail. My winch mantra now is: 'Loose when Launching' and 'Tight when retrieving'. Closehaul

https://macgregorsailors.com/forum/view ... mp#p353884

[Tsunami]

Thanks for the tips closehaul. I found a roller very similar that can use a larger diameter axle than 1/2 inch.
The bow shouldn't be heavy enough to cause too much stress.

Gotta love this forum

[NiceAft]

Tsunami,

In addition to everything just discussed, don’t forget to use a wide ratchet strap around the stern and the trailer. It is needed for those situations that you never want to happen. “Oops” and “Oh my gosh” won’t be the words that you utter.

[LakeMac26C]

I have a 26C with stock iron trailer. The bow roller sits about 2" under the vee of the hull and the roller is about 8" wide. I seem to be doing well with this setup. If the roller is too high, the boat may tend to ram into the roller instead of rolling over it, depending on your trailering technique.