The Speedster top Frame - Low Bow 2 High bow

[roy mawbey]

Justin,

Great bit of detective work there. I followed the page down slowly looking at all the photo's until you show one of the item you produced with the brass highly polished. I looked and saw two countersunk holes for securing screws side by side? I went back on thr photos and of course there is only one each side. Going back again I suddenly realised it was a reflection in the brass side

Going on further I saw the same problem as you with the strap going through the slot and just hanging down. I thought how do you tension that and secure. Looking then further you show the answer. Without that photo I would still be thinking

But I still have another question: The other end of the leather strap must be connected to the hood frame ready to pass it through the windscreen frame clip? How is the other end of the strap fixed by a clip and screws??

Restoration of an old car when all is not present is expensive and time consuming for sure. I remember my dad working on the cable brakes on a 1930's Riley nine 'Monaco' with cable quadrands missing.
When you can't see what should be there and then books on the subject were not clear and there's no internet to ask, it took him ages to locate the correct items.

But.. I suppose thats the fun of doing it and looking with satisfaction at the end result.

Nice job

Roy

[JTR70]

Hi Roy, Thank you! I must have done a good job of polishing. I completely understand what your father went through trying to reverse engineer things to create missing parts and before the internet no less. I can honestly say if Don had not shared the double back sinch I would have not thought to do it and the strap just would have hung there with only one pass. The purpose of this thread is to share all these little known details. Speaking of which here is how the other end of this strap is secured:

The end of the strap is anchored into the latch tang by a single rivet which was steel originally in the center of this embossed relief.

Original large flat-head steel rivet for the strap pictured here.

This embossment allows the strap to seat down in level with the mount flange surface for a flush fit against the header bow.

New leather straps. Tony Singer did a beautiful job and made them to Don's exact specifications. I ordered an extra pair just to have on hand and asked that they be 200MM in length. Way more than I'll need but they can always be shortened.

With all the drilling and fitment now complete these new recievers were ready for thier final finish in chrome plate.

I wasn't about to send these to just any chrome plater; Most shop are notorious for buzzing off edges and details. There was only one guy I trusted with these, so off to Victor Miles they went. He of course did a fantastic job.

It took some doing with alot of help but there she is a fully functional version 1 speedster top latch. The strap will need shortening but the 2mm thickness is right-on and fits firmly in the eyelet for the second pass. Don was right!

An initial observation: This unit has only been mocked up loose as pictured with no hard sinching, no canvas or rubber seal tension on it etc. The design is very, very hard on the leather and asking it to literally bend over backwards takes its toll very quickly I can tell already. These straps really are not long for this world so Don Zingg's earlier statement that in all his travels he never saw an intact original strap rings completely true. Great care will really have to taken each time the straps are "sinched up" so they'll survive just a bit longer. Thanks for reading this. Justin

[roy mawbey]

Very nice securing method for the other end of the strap Justin. All in all a super job. Yes, I think you could trust Victor with anything you send him.

I know now so much about speedster frames and straps and clips!!!

Cheers

Roy

[JTR70]

Thank you very much Roy!

One last detail note concerning these first latches before we move on. Of the handful of examples I have seen in photos the latch tang is shown secured to the header bow by screws. This is incorrect and was originally held on by steel domed rivets.

This is speedster #5 from that old article in Excellence showing the tang incorrectly screwed on. The leather straps also look too thin as per Don Zingg's specs. The old article went on to say that these tangs were actually missing and had to fabricated from an original example; they did a very nice job!

This example shot taken from the "speedster TYP 540" book by Steve Heinrichs shows it a bit more correct with copper rivets instead of screws. This example tang definitely strikes me as not being original. The raised embossment is not clean, the rivet for the strap anchor is too high and not centered and the tang's spade seems too long and flat. Yet another example of this very limited old hardware coming up missing. The new leather strap seems on the thin side as well.

Here is an undisturbed original with its Steel domed solid rivets intact. I understand why they would use screws or softer metal rivets. Due to the houndstooth header bow wrap and new paint the rivets would have to be flared cold. Unless you have the proper tool and die its pretty hard to do without heat, especially in that tight and confined trough of the inner header bow.

Just wanted to note how the factory originally did it. The hole drilled into the tang was done after the original straps broke. The old owners thought it best to just screw this tang directly onto the their windshield frame. I am just glad they were still with this top frame. From all I that I have gathered this is quite literally the proverbial "hens Tooth". Next evolutionary change up next. Thanks for reading this! Justin

[JTR70]

Front latch changes.

As stated by Don Zingg earlier this initial leather strap version latch was phased out by speedster #44. (80044)

The very familiar hook and toggle latch mechanism was phased in and the unit itself remained unchanged all the way through productions end in 1958.

What was unique about this initial latch change was the way it was mounted to the header bow beginning around speedster #45 (80045) According to Steve Heinrichs "speedster Type 540" book the Toggle was mounted directly to the side of the header bow as the example photo above illustrates. Due to either poor mechanical leverage or metal fatigue to the mounting surface on the header this initial configuration was gone by Speedster #82.(80082) The equally familiar angle bracket base was introduced and it too remained unchanged all the way through productions end in '58.

[JTR70]

More evolution details for the short lived low bow top frame. Even though only about 300 first Gen frames were produced there were other small unique changes along the way. The following shots and details are direct side by side comparisons of a low bow frame at the very beginning and one toward the end.

By the 266th frame(tan frame above)the headerbow was set and would see no more changes through the speedster production run. The header itself though still two sheets of metal was now punched from a single piece and no longer comprised of four seperate pieces gas welded together like the early version pictured with it. The familiar angle bracket for the toggle latch also set.

Both frames still virtually identicle with only a few small differences.

While the solid steel rivet was used throughout the lowbow run a change to a Rosette style rivet on the actual bow pivot points (only) occured sometime down the line.

Again the rossette style was found on the Bow pivots only.

Another slight change was at the "dog leg" kick on the rear bow. The very early style was pounded a bit flatter at this tip.

A final small difference was to the upper linkage arm. The initial version was almost flat with two slight kicks in it. The later versions had third bend added for better clearance as the top folded up.
Thanks for reading this! Justin