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53KR in a Low Boy Frame

PostPosted: Sun Oct 25, 2020 9:20 pm
by DaveAus
Hi,

My name is David and Im new to K models and this form but not to vintage Harley.

I recently purchased a 53KR which is a 60KR with a 53 number stamped into it in a Low Boy frame.

My plan is to sort it out and do some vintage Road Racing

The frame seemed to have a Sportster engine in it at some time in its life.

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My first question is, are there any challenges in running a K motor in a Low Boy Frame and is there any way to run a drum brake with the original Low Boy swing arm?

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Thanks
Dave

Re: 53KR in a Low Boy Frame

PostPosted: Mon Oct 26, 2020 6:08 am
by thefrenchowl
More a HighBoy than a LowBoy frame...

Doesn't look factory made but does look like Dick Hammer type frame that came about before the factory HighBoy:

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Maybe Bill can shime in and tell us if I'm right in thinking Jerry Branch made these mods on a few KR/XLR std frames.

Anyway, nice set up, you should try to find its history.

You could check for us if all tube steering head is a later mod (ie welded on old) or if it was build as this...

And don't try either to fit parts that were never on it...

OHV that was at one time in it is a race one as well, XLR...

Patrick

Re: 53KR in a Low Boy Frame

PostPosted: Mon Oct 26, 2020 8:06 am
by hugoct
The frame is a second generation KRTT high boy frame.
Originally it would have had the unique swing arm that these frames came with.
These frames first appeared in 1966.
These frames were replaced with the first version of the lowboy in mid 1967.
These frames used a unique oil tank.
It is a better Dirt Track or TT frame than a road race frame.
The "Sportster" motor appears to be an Iron XR or Sportster XLRTT.
Is that motor still available?
What is the motor number of the KR motor.
Any history or chain of custody?

Re: 53KR in a Low Boy Frame

PostPosted: Mon Oct 26, 2020 4:57 pm
by DaveAus
Thanks for the information guys, much appreciated.

I don't have the bike in my hands as yet but I do have the rear swing arm.

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I've chased down where the frame came from and her's a pic and the spiel when it was on ebay

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And the engine number can be found in the "Final list of expert entries for the 50 mile National Championship. Springfield August 23 1964" ridden by John Crawford - Monomouth Junction New Jersey number 25U.

The guy that sold it to me said it was this gentleman's engine but I'm not sure how you actually prove that.

Re: 53KR in a Low Boy Frame

PostPosted: Mon Oct 26, 2020 6:15 pm
by hugoct
The swing arm is from a late model XR750 frame.

Re: 53KR in a Low Boy Frame

PostPosted: Mon Oct 26, 2020 6:39 pm
by hayleyl
100% correct, swing arm is XR750. Cheers Hayley

Re: 53KR in a Low Boy Frame

PostPosted: Mon Oct 26, 2020 7:31 pm
by Ferrous_Head
Sorry to butt in but a question if I may ?

About the seat. Does anybody know about these seats ? Who made them ? Did Harley use them ?

I have a NOS one I intend using on my P 3 Race bike and was just curious. It's a bit garish with a metal-flake purple/brownish color which I will probably paint (hate to ruin what might be an original finish but the color is just simply not to my taste at all.

Re: 53KR in a Low Boy Frame

PostPosted: Mon Oct 26, 2020 8:10 pm
by hayleyl
Bubble seats (like on this scooter) were made by 'Bates' and there was another slightly pointier version made by 'Cutlass'. Cheers Hayley

Re: 53KR in a Low Boy Frame

PostPosted: Mon Oct 26, 2020 9:51 pm
by hugoct
The "TT" fiberglass seats as used by the Harley Factory guys came from Lipp Plastics (Nix, Rayborn, Markel, Haaby, Lawwill) or the Fiberglass Works (the Brelsford brothers and the Sehl brothers).

Re: 53KR in a Low Boy Frame

PostPosted: Mon Oct 26, 2020 10:13 pm
by Ferrous_Head
So, the seat on the bike in this thread, it's a "TT" seat ?

Would be nice to know what I call the one I have. I don't know if mine is "pointier" or not.