soft top corner curls

[jeffc280sl]

I have been working on my soft top frame and discovered something about the design of the frame that I did not know until moments ago.  This is my second 280SL so I've been around them for 20 years and for that time the rear corners of the top material have curled up because they come in contact with the wheel well in the storage area.

I don't think it is supposed to work this way.  Once I took the material off and got a good look at the mechanics of the folding top I discovered that the rear hoop is suspended up off the base of the storage area so that the corners do not flatten out.

Here are some pics to help visualize.  The first picture shows a rubber bumper that sometimes leaves black marks on the inside material of your soft top.  It plays a very important part in folding and storing the soft top.  The rear hoop needs to be pressed snuggly against this stop to make the corner suspension cam do its job.

Here is the bumper and rear hoop section as designed to fold.



Download Attachment: bumper hoop.JPG
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When the rear hoop is pressed snuggly up against the bumper and the top is folded into the rear compartment a cam at the hinge section is held firmly by a pin with a roller on it.  The pins purpose is to suspend the rear hoop so that it does not touch the bottom of the storage area.  That's my theory anyway.Here is a pic of the cam and pin I'm speaking about.



Download Attachment: cam and pin.JPG
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With the rear hoop resting snuggly up against the rubber stop this cam and pin do their job.  If the rear hoop is not pressed up against the stop when the top is folded and lowered the cam and pin with not line up in position to do their job and the pin may become bent.  Here is a pic of the corner of the rear hoop with a tape measure to show that it is suspended off the base approximately 1 inch.

 

Download Attachment: corner suspend.JPG
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The last picture shows the corner suspended from the base.  It also shows how the rear hoop nests with the other section of the top as it folds.  Very, very nicely designed and now much appreciated.



Download Attachment: rear hoop and mid section.JPG
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I will be interested to know how many of you have your rear hoop and material resting on the wheel well inside the storage area.  Maybe I'm the only one?

[Mike Hughes]

Good info!  Now, the question I have is how does the top material itself interfere with the proper "nesting" of the top frame in the compartment that causes the "corner curls," and how can one manipulate the top material to:

a.) prevent the "black mark" on the headliner, and
b.) prevent the "corner curls?"

[jeffc280sl]

I think the black marks can be dealt with by using new bumpers, maybe plastic ones that will not leave marks on the material.  The rear corner curls will not occur if the top is closed correctly because there is plenty of room for them to be stored if suspended properly.  The on;y other issue I can think of is the front bottom corners which need to be carefully folded into place.  I have heard of others using plastic from milk jugs so the material does not hangup on the body of the car.

[jameshoward]

Jeff,

I know what you mean. I went through similar though not nearly as detailed machinations with my frame when I was cleaning it up. I was trying to ascertain whether it was bent.

With no roof on the frame, it does reveal a good deal about the workings. I can well believe that the frame was designed without a roof on it though, because once you add the soft top, it changes everything. The folds of canvas between the frame loops use up a good deal of space. Add to that the fact that a new soft top with normal corners will push the rear bow up from the wheel well considerably and it soon becomes apparent that the stowage is affected. From the lower edge of the rear bow, a new hood has a skirt that is at least 1" and more like 2" that extends to make a good seal with the soft top box when the hood is up. It's pretty inflexible stuff, as I am sure you know. I've had a really good feel around the area where the corners meet the wheel arches and I can feel that the frame is very definately resting on these parts (it's a painful experience).

As for protecting the corners and front parts on a new roof, I use a sheet of quite stiff pastic to protect both the seal and the canvas. Taking down the roof is now a 2 person task and it's a pain. I think the key is to leave the thing down for long periods!

I did once see a car in London though where the roof could be opened and closed by the salesman (it was at Chelsea Classics or whatever they're called) using one hand only. It just went up and down like a dream and the soft top box closed beautifully without any additional pressure on the box top - unlike with my car.

Finally Jeff, since you have your roof off, if you manage to figure out what the 2 square rubber parts are where the hinge touches the chrome plate at the door pillar then let me know! I got new ones (made them given the price of replacements) but then go nowhere near the chrome.


JH

[Naj ✝︎]

JH,
Are the the rubbers you speak of?
Wondered where they go...



naj

[hands_aus]

Apparently the idea is that the corners are supposed to be tucked under when storing the soft top. This way a certain bias forms in the fabric.

This is anecdotal comment as my car deos not have a soft top frame yet.

There have been many discussions about this in the past.

[jeffc280sl]

James,

Thanks for your comments.  I agree the soft top material complicates some of the tolerances of the frame mechanism when putting down the top.  I'll just have to see what if anything can be done as I put the material back on the frame.  Maybe I will be able to move the material away from the crease near the rubber bumper so that the rear bow fits up tight against the bumper.  Does anyone have a manual for the soft top operation that goes into this level of detail?

Naj,

It's hard to see the detail from the pics you posted.  Can you make them brighter and give me an idea of size? b I assume a rubber bumper goes on the end of the piece shown in the next pic.  This pieces mounts vertically to the frame and the base with the two holes sits just above the chrome trim pieces surrounding the hinge area.  The rear window edge moulding is mounted to this piece after it is screwed to the frame.



Download Attachment: soft top frame.jpg
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[jameshoward]

Naj/Jeff,

Yes that's where the rubber bits go, although Naj, they look a little different to mine. (Not least because I made them I suppose!) I only have one on, and can't be bothered to put the either on because neither touch the chrome cap anyway.

Naj - thanks for continuing to reinforce my belief that there isn't a part of these cars you don't have a photo of.

JH

[jeffc280sl]

James,

The bracket that has the rubber piece on the end sits right over the leading edge of the chrome hinge cover.  Maybe 1/4 inch above it.  Where is yours located?

[J. Huber]

Not sure if this is related but it reveals another nuance of these tops. Nor am I really sure I can explain it...but here goes. I just noticed as I lifted the soft-top up and in place that when folded, the rigid leading edge of the canvas above the rear window had left a crease/tiny scratches in the bottom part of the plastic window. These two areas get close to each other when folded -- but while in the upright position they are not hitting. However, as the top goes into the case and gets smushed, the rear section rides over that edge, and they then hit. There is a spring loaded mechanism on each side that can be adjusted -- perhaps I want to make it harder for the slip over? Anybody have a clue what I am talking about?

[jeffc280sl]

I'll have a look as I put my soft top material on.