Chrysler 20 Trailer Question

pbagwell · Post by **pbagwell** » Mon May 14, 2012 2:24 am

I have a Chrysler 20 sailboat that I have owned for about 8 months. It came with a trailer, although we have kept it in a slip up until now, so I have never seen the underside of the boat. The trailer supports (bunks and guides) were in bad shape and I had to rebuild a all of it. I am not sure how high and wide to mount the bunk boards to make sure the keel clears the trailer frame.

Does anyone own a trailered C-20 and can give me some dimensions off their trailer? (a picture of their boat on the trailer would be awesome, as well). What I need is the width between bunk boards, length of the bunk boards, and how low the keel extends below the plane of the bunks. The height of the keel below the bottom of the hull and width of the keel (side to side) would be nice to have also since I need remount the keel guides as well. I have searched online and could not find any cross section information on the C-20 hull, so would appreciate any info you may have to help with my build.

Thanks Guys
Phil

Chrysler20%26 · Post by **Chrysler20%26** » Mon May 14, 2012 12:21 pm

Does your trailer look like this one http://www.flickr.com/photos/65343255@N06/

cs3079 · Post by **cs3079** » Mon May 14, 2012 1:21 pm

Hey!, That looks like my trailer Bob!

Anyway, I tried to give it a go. I'm no engineer... but I did take a drafting class in junior high. LMAO. Here's a link to some more pics and measurements. The OEM trailer measurements are not so straight forward, but they're a wonderful fit.

http://s1199.photobucket.com/albums/aa4 ... 20TRailer/

BTW, I forgot the keel base width on the drawing. It's 8" and the widest point and tapers down front and back.

Also, the exact width between bunk boards was difficult to measure with the boat on the trailer, too many curves and angles to deal with

I don't want to give you a bum number. Once I get her off the trailer..and into the lake I'll take some more measurements if you need them, but it could take a bit. I'm into some fiber-glassin' at present.

Good Luck Phil !!

Let me know if you need any numbers i can get you without turning myself into a pretzel again to get'em (LMAO again! - I gotta loose some ballast!!!)

lecker68 · Post by **lecker68** » Mon May 14, 2012 7:23 pm

Bruce if you hang a plumb or a level from inside of bunks then measure between them.

Chrysler20%26 · Post by **Chrysler20%26** » Mon May 14, 2012 9:53 pm

Yes it is Bruce's trailer, thank you Bruce.

cs3079 · Post by **cs3079** » Tue May 15, 2012 1:11 am

No prob Bob, glad to be of some actual help!

..... and Lyle, a plumb line... doh!, a good idea! I'll take the meas. today

one more thin,

how low the keel extends below the plane of the bunks

Where would that plane be at? Should I meas. from where the boat sits on the bunk at the front post? or mid point between bunks?

Thumbnail

pbagwell · Post by **pbagwell** » Tue May 15, 2012 5:04 am

Thanks Bruce and Bob. The pictures will help. To make sure I understand your terms: when you say
"Center of outer rail to center of post A = 14" ", Do you mean the distance from the side rail on the trailer to the center of the post, measured across the trailer (offset of the post from the outside of the trailer, in other words)?

Also, I am not sure I know what you mean when you say "Boat to center of axle 20".

My trailer looks different than Bruce's, though (much less dip along the keel, mine is flatter across the trailer). I will try to get some pictures tonight. The trailer is a tilt-on Dilly trailer, built in Texas back in 1979. I have no idea if it has changed over the years. When I bought the boat, the trailer had two 2x4 bunk boards, ~15" above the trailer frame and more or less level, about 8 feet long. The bunks were supported at each end from supports that were u-bolted around the frame. There were two additional 2x4 keel guides that were mounted closer to the center of the trailer and on edge...presumably to guide the keel and help center the boat on the trailer. The frame is split for the last 3-4 feet at the back to clear the rudder. All of the brackets were rusted and loose, so it was hard to take good measurements.

Since I have never had the boat on the trailer, I am not sure how high it should be above the frame for the keel to clear. I was going to shoot for around 15" since that is what the original bunks were set for. Most of the pictures I have seen on the web show longer bunk boards that sweep up toward the aft end of the boat and have a third support back there. For my trailer, there is not a good place for another support at the aft end, although it looks like my rear support is much further aft than the middle mount I have seen on the other pictures. Also, the original setup on my trailer did not have the bunks sweeping to follow the curve of the boat. With the supports at either end, it looks like the setup depended on the bend of the 2x4 between supports to provide the curvature to match the hull. I have no idea if this was 'as designed'. The last owner had used the trailer quite a bit, so presumably it must have worked.

Anyway, thanks for the info and I will post some pictures of the work in process tonight.

Phil

Chrysler20%26 · Post by **Chrysler20%26** » Tue May 15, 2012 9:59 am

Your trailer was not built, for the C-20. The bunk boards 1 1/2 x 5 1/2 x 11' 3" So lets say 2x6 x 11foot 3 inches ( treated ) Each board sites on 3 posts , one center an one at each end. First two posts are 13 inches an the one at the back of the boat is 19 inches. ( 6 inches higher than the first two posts ) Your trailer looks to be set up for a power boat, so go with your ORIGINAL 15 inches for the front two posts an the back post should be 21 inches high ( 6 inches higher than the front two posts ) You can make the keel guides when boat is on the trailer.

pbagwell · Post by **pbagwell** » Tue May 15, 2012 10:31 am

Thanks for the input. I will see what I can do to add a third support near the back. Right now, my supports are about 7 1/2 feet between centers, which is a bit longer than the ~ 5 1/2 feet for your trailers.

Phil

lecker68 · Post by **lecker68** » Tue May 15, 2012 3:48 pm

you might want to go to a marina that has a lift and be ready to build and they can lift it and set it on the trailer and still support the boat and you can build supports and they take the lift off.