Trailer bunks position for a Grady-White

Mike Chaffin

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I have a 1994 Grady-White Explorer. Where is the best place to position the trailer bunks, to properly support my boat. I have a tandem axle aluminum I-beam 7000 lb GVW trailer. I bought my boat without a trailer. Any info would be appreciated. Thanks Mike
 
As close to the stringers as possible. They're easy to locate and easy to take measurements or even just eyeball it to the outside of the hull. It's not an exact science - just get close - but err to the outboard side of the stringers based on strakes.
 
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I have a 1994 Grady-White Explorer. Where is the best place to position the trailer bunks, to properly support my boat. I have a tandem axle aluminum I-beam 7000 lb GVW trailer. I bought my boat without a trailer. Any info would be appreciated. Thanks Mike
I have a '92 Explorer. At work today but I can measure when I get home tomorrow. Just had a new trailer built a couple of years ago and researched this.

Chris
 
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I have a '92 Explorer. At work today but I can measure when I get home tomorrow. Just had a new trailer built a couple of years ago and researched this.

Chris
Thanks Chris. Can you please take a few pictures of all the support bunks.
 
Thanks Chris. Can you please take a few pictures of all the support bunks.
Sorry, crazy weekend and I didn't get a chance to get out to the boat. I'll get them tomorrow. PM me a number to text the photos to.

Chris
 
Here' the 2010 version


I was really interested in the info on that chart to see how my new trailer was set up by the manufacturer compared to what Grady recommended but the terminology confuses me. Other than the distance to port or starboard from the keel indicated in the drawing it is Greek to me. Anyone know what "LCG" stands for? How about "Buttock location and straight length"?
 
Mike,

Measured and the bunks are 53" apart center to center. I have pics if you can PM me a number to text them to. I got these dimensions from GW when I had the trailer built. The tops of the bunks are angled and they rest just inside of the stringers.

Chris
 
I was really interested in the info on that chart to see how my new trailer was set up by the manufacturer compared to what Grady recommended but the terminology confuses me. Other than the distance to port or starboard from the keel indicated in the drawing it is Greek to me. Anyone know what "LCG" stands for? How about "Buttock location and straight length"?
Halfhitch, LCG is longitudinal center of gravity (CG) from the intersection of the transom and keel. In other words, the CG of the boat with engines. I assume you want the trailer wheels slightly aft of that to provide 10-15% tongue weight. The buttocks are useful in designing lifts and trailers, if you want to get real technical. Buttocks: Slices of a boat made lengthwise, and top to bottom. Like slicing a banana the long way for a banana split. The buttock lines help to describe how the boat shape changes from center to edge. Take the 330 for example: Buttock 18 is essentially straight from the CG 132.32" aft, but farther out at B 36 it is only 116 straight.
 
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This is exactly the information I was looking for. I’m having a hard time making sense out of it however. I have a 208 so I can either set my bunks 15” or 29” from center, is that correct? And what else do I need to know?
 
Yes, the two inner stringers are on 30 inch spacing and 58 inch spacing. Which ones you chose depends on the bunk height to a degree and the clearance for the keel. You could have two sets of bunks, one aft at 58 inches and one forward at 30 inches but you don't really need that for a small hull like yours. The next important adjustment is the forward/aft positioning of the hull on the bunks. That affects the tongue weight and is a bit trickier to set up.
You also want to make sure that as the hull is driven or winched forward, the keel does not hit any cross members or axles.
 
Yes, the two inner stringers are on 30 inch spacing and 58 inch spacing. Which ones you chose depends on the bunk height to a degree and the clearance for the keel. You could have two sets of bunks, one aft at 58 inches and one forward at 30 inches but you don't really need that for a small hull like yours. The next important adjustment is the forward/aft positioning of the hull on the bunks. That affects the tongue weight and is a bit trickier to set up.
You also want to make sure that as the hull is driven or winched forward, the keel does not hit any cross members or axles.

30 and 58? it said mount the bunks at 15" or 29" from center? would that measure be to the inside of the 4" bunk?
 
Seasick is referring to spacing between bunks 30 & 58". 15" & 29" from the centre is the same spacing. Yes that is the inside, so space them 30" apart .
 
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I just had a trailer built for my 305 Express and had a similar question. I called Grady and 5 min later I had the trailer specs from the factory emailed to me. Give them a call and you'll have all your measurements exact.