Bracket degree

[Corey Mason]

Does anybody know the transom degree of our bertram 25's?

I have been seeing a ton of brackets for sale lately right near me for dirt cheap. Just curious if somebody already knew what bracket degree/angle would work for our b25's (its a sportfisher). I know I can measure I just haven't had the time lately.

[CamB25]

Corey,

14 degrees

[Corey Mason]

Thanks cam.

Is there any variance I could get away with? +/- 2 degrees maybe?

[CamB25]

+/- a degree or two shouldn't make that much difference. You might be able to make a shim for the bracket or engine to tweak it.

[Corey Mason]

What do you guys do about that damn bumpout?

Push the bracket out further and shim up the excess or?

Got an armstrong bracket I'm looking at for $1,000 right now that's just 45min away.

[CamB25]

Twin bracket or single? The tank on the twin maybe too wide to mount to the bump out - overhangs.

[Corey Mason]

Twin.

That's kind of what I was wondering. Does everybody just get a tank that fits in the bump and then readjust the swim platform to sit flush with the stern after it goes past the bump?

[CamB25]

I can't speak for everyone, but when I was considering a bracket, it was custom. You make a template of the transom shape at the mounting height. Or buy one that is straight and unfinished and make filler pieces after install. Or what ever you think might work.

Or buy the right model from Armstrong...they make a model that fits.

Years ago I made some measurements that might help:

https://www.amazon.com/photos/share/Vlb ... VsYynZmoI2

Or keep it simple and cut the transom!
https://www.amazon.com/photos/share/zPI ... WCxn7MpUoz

[Corey Mason]

Well....I bought an Armstrong bracket for $996!

Guy told me it was a 16° bracket so we will see. I'll get to tinkering with it this Christmas break and see what we're gonna do.

I figure worst case if the bracket is just a mess then I can resell for a profit. It even came with the $300 swim ladder.


Has anybody cut the bump to have the bracket fit inside it?

[Raybo Marine NY]

for future reference

[Corey Mason]

for future reference

This could also be used in the opposite manner to determine the bracket angle too right? Just measure on the top of the bracket, (the top of the bracket would take place of the Keel) right?

[CamB25]

Yes. With this method you could compare the transom angle to the bracket angle without doing math.

The framing square must be 14" on the short side for the 1/4"= 1 degree conversion to work. The generalized equation for any square is:

Angle(deg) = invTan(measurement (in)/short side of square(in))

[Yannis]

Cam, you’re waaay ahead man !

What is this, an inverse tangent for crying out loud... Do not try to explain, i believe you!!

[Corey Mason]

Cool. Father in law is going to come over this weekend to help with the bracket. Heavier than I anticipated.

Would it hurt anything if we cut the bump flush with the rest of the transom to avoid fabbing the bracket? We could either cut down the entire bump, or just cut the section of the bracket out of the bump. Would look really silly with the bracket off, but once it's on there would probably look just fine.

I'm assuming I would be compromising any integrity by doing this. I would just be murdering the "classic Bertram" theme. Which, kinda hits the heart but at the end of the day...I'm loyal to making the boat I want, not to the Bertram company. Besides, almost every boat out there has a flat transom so it wouldn't look abnormal

[CamB25]

Wow...I would not recommend that method...for many reasons:
1. The two layers of plywood comprise most/all of the strength and bearing surface to mount your bracket
2. If you cut it flush, you will be left with a gaping hole in the boat...the exact size of the bump out. there is nothing on the inside.
3. Modifying an aluminum bracket is a lot easier than modifying a boat.
4. Adding to the boat is much easier than taking away and re-making
4. 100 more reasons...

Leave the bump out as-is and work around it.

Ideas:
Once you figure out the exact height where the bracket will mount (not easy, not trivial, and not easily changeable if you make a mistake), you can build out the outboard curved areas of the transom to be flush with the leading edge of the bracket, and you can build out the transom bump out if the bracket tank overhangs a bit. Add to the boat, don't take away. Avoid modifying the bracket.

You should consider significantly reinforcing the entire transom to ensure the bracket + engine load (1500 lbs?) is adequately carried by the structure of the boat. The bracket and boat should at act as a single structure. If you just bolt it on and hope for the best, you are likely to have a structural failure. 1500 lbs x 30" is a 2200 bending moment on your transom. not trivial.

I over-thought the whole bracket idea for a couple of years and decided it wasn't worth the effort....a sawsall requires little to no calculus to operate. But many boats use them successfully, so it can be done!

Yannis - Your countryman is responsible for all of my triganometric skills - Pythagoras!

[Corey Mason]

It's been awhile since I've even looked at the boat. I don't even have the old out drives out yet. I didn't realize how much structural support there was in the bumpout.

Are you suggesting to simply fiberglass on the transom where the upper platform of the bracket would touch the boat? Kind of like run a horizontal line just for the purpose of making it flush? Should I make the the new fiberglass the exact width of the bracket or extend it an inch or two above and below the line?

And then swelling the bottom of the bump to accommodate the tank?

[Corey Mason]

Would be about #1100 with twin 150's and bracket (aluminum). Or about #700-800 if I run a single 250/300

[CamB25]

Corey,

You'll need to rebuild the transom before worrying about the bracket. Get it to look like this on the outside, and new wood in the bump out and everything glassed back together. I can't find my inside pictures at the moment.

https://www.amazon.com/photos/share/tSx ... AfhxvSM43k

Here's a picture of a boat with filler pieces made to take up the gap between the bracket and transom (from Cap'n Bone's collection). See how close the top of the bracket tank is to the edge of the bump out? I bet it hangs over a bit.

https://www.amazon.com/photos/share/6Bv ... klQvqnSWTu

If you are considering a single engine, the easiest, quickest, cheapest way to get in the water is to 1) rebuild transom, and 2) buy a single engine bracket. This is mine from years ago. My meds wore off and I picked up the damn sawzall...again! Don't ask...I sold it a long time ago.

https://www.amazon.com/photos/share/ZJP ... kvktF0kxc8

Cam

[Corey Mason]

I like the bracket with the mercury on that.

That single bracket is horrendous. I'm sorry, I dont mean insult, it is just bad. I've thought that yes, it is very simple and easy to do it that way, but it would squat the stern terribly I think even with just 1 engine. It also makes my eyes hurt looking at it!

What do you think those big "shims" were made out of? Glass'ed wood? Im almost certain that this is the direction I will take.

The toughest decision now will be either twins or a single. I'm already set that if its a single it absolutely must be a 30" (just my personal preference). I would love 30" shaft on twins too, but that's probably asking too much. I really want to get twin 140 zukes. It most likely is going to be whatever I can find locally for a good deal. Most likely whatever I buy will be a blown motor so I can get it very cheap and just rebuild it myself.

[Waytooslow]

I would taper the edges of the shims so a little overhang top and bottom would not bother me. The shims would add some strength as well. Personally I am going to figure out a way to have the swim platform on the bracket follow the existing transom contours but then I do not have an existing bracket. Have you thought about asking Armstrong what they would charge to modify yours?
I may need to go with an Armstrong but hope to find a less expensive option. I am getting close to starting on filling the I/O holes and my plan is to cut out most of the bump out and re-glass a whole new transom.