Proper frame for my 1957 Sportster

[imcranco]

WOW! Thanks , all the info is greatly appreciate. Looks like my E6 frame is the proper one for my "57 engine (s/n 57XL1729)
I'm new to the website and I must say everyone has been very helpful. I'm sure I will have more questions.

[JerrryR]

Hi Imcranco. Your last post intrigues me. Is your E6 frame a K model frame or an XL frame? I am not aware of any XL frames produced with that early of a date code. Does your top motor mount look like the #1 picture below, a K frame, or the #2 picture, an XL frame?
#1

1952 K Frame hollow footpeg 3.JPG (23.67 KiB) Viewed 16370 times

#2

IMG_2801.JPG (278.15 KiB) Viewed 16370 times

Take care,
JerryR

[thefrenchowl]

The 1st ever photos (12 in all) of the Sportster prototype were filed at Pohlman Studios on the 20th of April 1956...

Makes it a touch tight for your E6 frame to be a Sportster one...

Patrick

[Yard Dog]

Patrick,

Are those Pohlman photos available for purchase or viewing ? I would love to see them . Do you know if the prototype was mocked up in a 56 frame or did it have a steel top mount ?

Jack

[Hammie13]

I know they built the first OHV Sportster in 1953 using all K stuff. I'm sure that's where the flat spot on the underside of the back bone originated. I'm sure they built,then dis-assembled many more "Pilot" bikes afterward and returned the frames to the factory floor. I worked at G.M for 16 years and every year we did test cars on the line to verify the build process. Afterward they returned all the carryover parts back to the shop floor for use on the line. I'm not sure,but I'd bet H.D. did the same thing,so there is a good chance some flat spotted frames made it out on '54-'55&'56 K Models....JMHO. Mike

[hennesse]

I know they built the first OHV Sportster in 1953 using all K stuff. I'm sure that's where the flat spot on the underside of the back bone originated. Mike

Over on T. F. Owl's website is a photo of the 1953 KL Overhead Valve prototype. Not exactly a Sportster. I wonder whatever happened to that bike.

Well hidden over there are photos of the 1972 Sportster Overhead Cam prototype left side and right side I like the dual exhaust setup!

[thefrenchowl]

Hi,

The KL was started around 1948 and was stopped in 54/55, which gave H-D very little time to derive the Sportster engine from the K bottom end, hence the huge compromises it got...

KL was in fact, if you study the photos, a big bore/short stroke engine, so at a guess, with little torque and high revs... The management thought this would never sell to the H-D traditional clientele. So we got the small bore long stroke Sportster instead, which suits me and others just fine.

The only remnants of the KL is a set of cases with cast in cylindrers if I recall right... From 1954/55, with more case finning than on the 53 Pohlman photo, which also show it was running pretty hot!!!

All the H-D photographic archives were held and owned by the Pohlman Studios in Milwaukee. There was a time when you could order 8 x 10 shots directly from them if you knew what to look for, it is mostly 8 x 10 glass plates stored consequently by number and the listing is not a help, being usually filled by non motorcyclists.

So you'd order 18654 to 18666, and got whatever they were. I managed to get some help from Allan Girdler in 1985, actually purchased a copy of the listing in 1988, it covers some 30 000 negatives over 127 pages tightly hand written or typed... The early listing, neg. 1 to 13607 was so worn out it did not survive. So page 1 starts at 13608, 06-12-1934, listed as "tourists", probably visitors at the factory.

Some time ago, when the H-D museum came about, H-D purchased back all the negatives from Pohlman. They are now in a vault and nobody can access them...

What I managed to get is on my site, mostly racers which is my thing...

As far as I know, there're only a few copies out there with collectors, it's a rare thing

Patrick

[thefrenchowl]

Pohlman Files samples:





Patrick

[EKHKHK56]

Hi folks. The KL was like the V-Rod of the day, short stroke, big bore and 60 degree splayed cylinders. Sort of the style many sport bikes have evolved to. For me, the long stroke 45 degree gets it done. Is the frame in question using the top Cast or Fabricated mount? Erik

[Hammie13]

Love the race tank with chest pad on the '72 OHV Snortster,are those stock XR750 pieces?