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Re: 57 frame on ebay

PostPosted: Mon Feb 12, 2018 6:31 pm
by thefrenchowl
A 56K frame would have a different top motor mount and a 66 would have a different seat casting.


The 1st Sportster was photographed in April 1956, with Sportster frame... and soon after that, they started rolling off the assembly line ; O )

Patrick

Re: 57 frame on ebay

PostPosted: Mon Feb 12, 2018 8:36 pm
by wz507
thefrenchowl wrote:
A 56K frame would have a different top motor mount and a 66 would have a different seat casting.


The 1st Sportster was photographed in April 1956, with Sportster frame... and soon after that, they started rolling off the assembly line ; O )

Patrick

Here are some images of an E6 (May ’56) frame with the cast iron top engine mount and the backbone rearward of the top mount squished to receive the new taller OHV Sportster engine due for introduction in a few months. Don't know when the K Model cast top engine mount was switched over to the sheet metal Sportster top mount, other than not in May '56?
LR E6 stamp.jpg
LR E6 stamp.jpg (62.56 KiB) Viewed 14980 times


LR E6 Frame.jpg
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LR Squished backbone.jpg
LR Squished backbone.jpg (200.31 KiB) Viewed 14980 times

Re: 57 frame on ebay

PostPosted: Mon Feb 12, 2018 8:50 pm
by EKHKHK56
Same frame I have, have 3 56. All 56 frames I've seen have the "OHV Crush".

Re: 57 frame on ebay

PostPosted: Mon Feb 12, 2018 10:05 pm
by JerrryR
I believe the frame transition took place in June of 56. I have seen an F6 frame with the cast K model top motor mount as well as an F6 frame with the Sportster top motor mount. This appears to be the month when Harley made the change. I have 2 K frames both with F3 date stamps, one has the uncut -52 neck used on the 53K and the other has the raked, cut and reworked, -52 neck casting used on the 54 K models. There were 3 versions of the K frame used in 56. I have few data points but the ones I have are:
Smashed backbone as early as "A6"
Ridge-less neck casting up until at least "A6"
Ridged neck casting as early as "D6"
JerryR

Re: 57 frame on ebay

PostPosted: Tue Feb 13, 2018 12:01 pm
by thefrenchowl
Thanks for the info, I would agree that June 56 is the start of making Sportsters ready for the new season.

When I had both K and X frames at home (no more sadly...) I did notice a big difference in the thickness of the reinforcing rib on the top of the seat casting... Thin on both uncoded K frames I had and quite thicker on all Sportsters...

Any info on these different castings?

See ya,

Patrick

Re: 57 frame on ebay

PostPosted: Tue Feb 13, 2018 1:03 pm
by JerrryR
I will do this in several post in order to include images. Here is what I think about the seat castings:

Ist K, Seat casting did not have the fender strut supports as part of the casting. Strut supports were welded on. Believe these were only used in early 52. Initial castings had threaded downtubes, later ones used the hold down plate for the seat springs etc.

Snipped Early K Frame Welded Strut Support Threaded Downtube 1.JPG
Snipped Early K Frame Welded Strut Support Threaded Downtube 1.JPG (146.87 KiB) Viewed 14958 times

Snipped Early K Frame Welded Strut Support Threaded Downtube 2.JPG
Snipped Early K Frame Welded Strut Support Threaded Downtube 2.JPG (133.75 KiB) Viewed 14958 times

Snipped Early K Frame Welded Strut Support Threaded Downtube 3.JPG
Snipped Early K Frame Welded Strut Support Threaded Downtube 3.JPG (184.14 KiB) Viewed 14958 times

Re: 57 frame on ebay

PostPosted: Tue Feb 13, 2018 1:33 pm
by JerrryR
The second version of the K frame seat casting incorporated as part of the casting the fender strut supports. I believe this happened relatively early in the 52 model year based on the number of frame samples viewed for 52 & 53. The Casting changed by or as a running change in the 56 model year. It became thicker/more ridged.

Engine Teardown 57XL Group 1 057.JPG
Engine Teardown 57XL Group 1 057.JPG (262.72 KiB) Viewed 14957 times

Engine Teardown 57XL Group 1 065.JPG
Engine Teardown 57XL Group 1 065.JPG (240.49 KiB) Viewed 14957 times


I believe the next seat casting changed happened in the mid 64 model year with the boss on the lower right underside to hold the voltage regulator in 65 for the CHs and the coil in 65 for the XLHs.

L4 Frame 4.JPG
L4 Frame 4.JPG (45.43 KiB) Viewed 14957 times

Re: 57 frame on ebay

PostPosted: Tue Feb 13, 2018 1:54 pm
by JerrryR
In 67 the XLH went to a new casting and frame configuration to accommodate the electric start motor. I believe this seat casting was used for the XLHs from 67 through 72 and for the XLCHs from 70 through 72. I believe that the XLHs and XLCHs used a common seat casting and frame between 70 and 72. The difference in the "finished" seat castings in 70 and 71 was the addition of the welded on lunch box oil tank bracket for the XLCH. In 72 the casting had two threaded holes on the underside to accommodate a bolt on lunch box oil tank bracket for the XLCH. Please let me know if I have any of this wrong in the last 3 posts. Also if you have any K frame data points to close in on when these changes occurred, I would appreciate the information.
Thanks,
JerryR

72 Frame 3B cropped.jpg
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72 Frame 7B croppped.jpg
72 Frame 7B croppped.jpg (91.83 KiB) Viewed 14957 times


1972-A2 Frame 3.JPG
1972-A2 Frame 3.JPG (30.04 KiB) Viewed 14957 times

Re: 57 frame on ebay

PostPosted: Wed Feb 14, 2018 1:02 am
by hennesse
JerrryR wrote: Having said all this let me summarize by saying the only difference I am aware of in the XL and XLH frames between 57 and mid 64 when the seat casting changed is the small speedo bracket hole on the right side of the neck casting.


Another difference is the Security Codes which appear on 1962 to 1969 frames. If you look closely at Jerry's photo named "H6 Frame XLCH 4.jpg" - the one with the date 12/28/2013 on it - you will see a faint Security Code (aka Anti-Theft Number) next to the little hole on the neck. The initial letter will identify it to one or two years.

I've updated the article Technical : Numbers with a section on Frame Security Numbers.