New bimini top stress on windshield frame

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mark1905

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I just purchased and installed a beautiful new Carver Super Sport Bimini top from boatcoversdirect.com along with the rear support bar option. The deck cleats are mounted to the windshield frame about 12" up from the base like most biminis.

Although, I'm super paranoid about the flexing of the top and the stress on the windshield frame. As I was being towed behind the boat wakeskating yesterday, I was cringing watching that thing flex back and forth every time we'd go over some wake.

Question is: how much flex is too much? Has anyone ever had problems with windshield or frame breaking? Am I ok here?
 

V153

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Re: New bimini top stress on windshield frame

I've never heard of a bimini breaking the windshield/frame but that doesn't mean it can't happen. I'm in the canvas business and personally have never liked attatching biminis to the windshield. Though if you have a fwd curtain/enclosure it's the only way. If you do not have a fwd curtain then I highly recommend mounting the 'cleats' aka: eye straps more forward & outboard.

When I install a top whether I made it or not I try to have the straps follow the lines of the frame. (See my boat.) For at least a couple reasons. It looks better plus it distributes the load more evenly. Don't be afraid to pull the straps tight. New is the time to put a purty good tug on em

Post a couple pics of yours & mebbe I can offer some advice?
 

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lhunting

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Re: New bimini top stress on windshield frame

Mark1905 I'm in the same boat as you (ahaha so Punny). I currently have a Bimini top that the frame is attached to my side windshield however the top is, like V153 mentioned snaps to the forward windshield creating the enclosure. Now with that being said I don't currently recall seeing any play or vibrations on my windshield with the current setup. However it is the factory top that is only about 4'8"-4' 10" in height from the floor of the boat and for most adults thats just to short to walk under. I am looking to replace mine with one that is taller and I also have the same fear of breaking those side windows. So I'll be paying close attention to this thread to see if anyone has broke or had to repair their windshield because of a Bimini top mounted to the windshield.
 

mark1905

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Re: New bimini top stress on windshield frame

Hi all..

What's flexing is the actual windshield frame as the top bounces to the sides. The front straps on this particular type of top are attached to the frame itself, and I'm using the rear solid brace option in the back. I'll try and get a pic later this week when the boat gets uncovered again for some minor service. Overall, the top itself looks incredible.. I'm very pleased. I like this new Carver Super Sport design with the dog leg in the support bar that lets the top lay very flat when closed. Perfect fit..


Mine looks almost identical to this picture except for the addition of the rear support bar. My deck cleats and front straps are in the same exact location:
sst_image.jpg


FWIW, I would recommend these guys if you are looking for a top. You won't find a better quality top for less: http://www.boatcoversdirect.com/products/bimini_tops/specialty/47/
 

LippCJ7

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Re: New bimini top stress on windshield frame

Mines mounted the same way and I don't get the windshield flex at all, my top was installed at the factory though I wonder if that makes any difference....
 

mark1905

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Re: New bimini top stress on windshield frame

With a 25' BR like you've got in your sig, I'm betting that your windshield frame may also be a little bigger and/or heavy duty..?
 

mark1905

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Re: New bimini top stress on windshield frame

Here are a couple shots of my top:

1jZgc.jpg


sdMnN.jpg
 

V153

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Re: New bimini top stress on windshield frame

I'm afraid you're gonna get some flex with that top configuration regardless Mark. The only way to stop it would be to move the mounting point off the w/s frame & down to the gunnal. Of course this will cost you a fair amount of bimini height unless you lengthen the main frame.

I'm betting when you look at the boat from bow or stern the bimin frame, stiff bars and straps are near perpendicular to the floor. Read no lateral support. And when you balance all that stuff on top of a couple side windows yer gonna get flex.

Short of moving the mounts there's not a whole lot you can do. I've seen the addition of a diagonal stiff bar aft. I've also seen the addition of a pair of diagonal straps to just outside the w/s walk through. Both of these remedys will help but remember you're still focusing a lot of stress on those two questionable mounting points.

In the meantime make sure the fittings are tight tight tight. No slop between deck mounts & eye ends or jaw slides & eye ends. Also, it appears the w/s mount is black nylon. If so that's a very weak link. Replace it with stainless and tighten it up.

Carry on.
 

LippCJ7

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Re: New bimini top stress on windshield frame

With a 25' BR like you've got in your sig, I'm betting that your windshield frame may also be a little bigger and/or heavy duty..?

I suppose it could be, I never really looked to be honest....
 

mark1905

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Re: New bimini top stress on windshield frame

Thanks much for the input..

Yeah, I've got SS deck cleats on order. Those black nylons are the originals from the old stock vinyl snap top. As long as I'm ok with the flex, then I'll take it. I'm just not used to things pulling on the windshield frame like that since I never once ran the old top. I also popped off all the rubber foam inserts and made sure that every mounting screw was tight.. a few were loose which I think was adding to the flex/shifting. Looking good now, and loving the top!
 

mark1905

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Re: New bimini top stress on windshield frame

So.. ok.. wait.

After taking it out today, I re-checked the mounting screws around the base of the windshield frame.. and found them all to be lose again! It seems like all the flex on the frame may be causing them to back out? What can I do to prevent this? Some kind of loc-tite?
 

drrpm

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Oct 24, 2008
Messages
707
Re: New bimini top stress on windshield frame

My Bimini top pulled the windshield frame off while I was running aound 50 mph trying to beat a storm to the dock. I hit a wind gust and the force tore it loose with no previous flexing. I was able to repair it myself but I keep the speed below 35 now with the top up. It should not be flexing period. I'd say moving the strap attachment points to a stronger point like the base of the windshield frame or the hull will be necessary.
 

SeanMcl

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Re: New bimini top stress on windshield frame

You can also lengthen the front straps, and then cross them to provide lateral stability. That works really well to eliminate the side to side shaking.
 

mjgates

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May 5, 2010
Messages
97
Re: New bimini top stress on windshield frame

I've never heard of a bimini breaking the windshield/frame but that doesn't mean it can't happen. I'm in the canvas business and personally have never liked attatching biminis to the windshield. Though if you have a fwd curtain/enclosure it's the only way. If you do not have a fwd curtain then I highly recommend mounting the 'cleats' aka: eye straps more forward & outboard.

When I install a top whether I made it or not I try to have the straps follow the lines of the frame. (See my boat.) For at least a couple reasons. It looks better plus it distributes the load more evenly. Don't be afraid to pull the straps tight. New is the time to put a purty good tug on em

Post a couple pics of yours & mebbe I can offer some advice?

I have a bimini top canvas question. Mine started to rip at the seem where it goes around the frame last year. Since then I can't put it up as the wind catches the canvas. I would love to have it back this year to get the kids out of the sun. My question is, can I repair the canvas, or do I need to buy new canvas for my frame. Mom is quite talented with sewing if that would work.
 

riptide09

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Re: New bimini top stress on windshield frame

I have been reading this thread with great interest as I am about to order a bimini top for my boat. My boat is a 2003 FourWinns Freedom 170 runabout. After taking all the measurements I really need to mount the bimini approximately 14 to 15" inches in front of the end point of the side windshields. If I mount the bimini to the windshield my installation would be similar to the pictures in this thread.

Lets suppose I want to mount the bimini on the outside of the windshield. In that case there is a small "ledge" outside of the windshield but it is only about 1/2" wide at best. That means I would have to install the mounts on the vertical edge/side of the boat. Is there mounting hardware for this type of installation?
 

mike-the-cobra

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Re: New bimini top stress on windshield frame

I have my bimin mounted to the top of the winshield, only difference is I have the straps running down to gunwale in front. I have observed and flexing.
 

V153

Lieutenant Commander
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Apr 16, 2011
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1,764
Re: New bimini top stress on windshield frame

I have been reading this thread with great interest as I am about to order a bimini top for my boat. My boat is a 2003 FourWinns Freedom 170 runabout. After taking all the measurements I really need to mount the bimini approximately 14 to 15" inches in front of the end point of the side windshields. If I mount the bimini to the windshield my installation would be similar to the pictures in this thread.

Lets suppose I want to mount the bimini on the outside of the windshield. In that case there is a small "ledge" outside of the windshield but it is only about 1/2" wide at best. That means I would have to install the mounts on the vertical edge/side of the boat. Is there mounting hardware for this type of installation?
Absolutely. There are several different types of mount available. In your case I'd spring for a pair of SS side mounts & beef em up with a backer plate.
 

V153

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Re: New bimini top stress on windshield frame

I have a bimini top canvas question. Mine started to rip at the seem where it goes around the frame last year. Since then I can't put it up as the wind catches the canvas. I would love to have it back this year to get the kids out of the sun. My question is, can I repair the canvas, or do I need to buy new canvas for my frame. Mom is quite talented with sewing if that would work.
You say seam. Is the thread going away or is the material itself tearing? If the material's shot obviously you'll have to replace it, but if it's just the thread you can have it restitched.

My Mom's a talented 'seamstress' too but I made her sign a "no compete" clause when I opened the business ...
 

V153

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Re: New bimini top stress on windshield frame

You can also lengthen the front straps, and then cross them to provide lateral stability. That works really well to eliminate the side to side shaking.
I agree but buy a pair of new, longer straps & keep the origionals in place.
 

mjgates

Petty Officer 3rd Class
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May 5, 2010
Messages
97
Re: New bimini top stress on windshield frame

You say seam. Is the thread going away or is the material itself tearing? If the material's shot obviously you'll have to replace it, but if it's just the thread you can have it restitched.

My Mom's a talented 'seamstress' too but I made her sign a "no compete" clause when I opened the business ...

Thanks man. I'll post some pics tomorrow of the tear. Had an abrupt ending to working on the boat this evening when I ran upon a wasps nest under the cover. About to shoot up my epupin (sp?) and call it quits for the evening.
 
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