Board index Flathead Power-Technical Questions, Answers, and Suggestions Knuckles Frames-old/repros


Moderators: Curt!, Pa

Post Mon May 01, 2000 5:40 pm

Posts: 31
Location: Southwest-Germany

I`m in need of a frame, either Knuckle or BT Flathead. Where do I get one, and most of all what do I have to pay for one with untouched neck.

Post Mon May 01, 2000 6:39 pm

Posts: 582
Location: meridian, id. usa
V-Twins frame is PN 51-1009, goes for 1605.75 retail. have seen stock oem frames as high as 2500.00 with all the brackets intact and as low as 900.00 butchered. check out you just may find one there

try this one

[This message has been edited by dotman (edited 02 May 2000).]

Post Tue May 02, 2000 2:57 am

Posts: 8
I've got a question 'bout frames. The early bikes had 18" wheels w. a 28 deg. neck angle. Is anyone building nice repop frames w. 28x necks? It seems like everywhere I look 30 deg. is the smallest which is for 16" rims. I want to build a 61ci knuck w. 18" rims. I 'preciate your comments.

Post Tue May 02, 2000 8:02 pm

Posts: 109
Location: holland
dotman , icannot open that url you gave, is it ok?

Post Tue May 02, 2000 10:22 pm

Posts: 109
Location: holland
i am Looking for a 37 frame myself , there is one on ebay it says 37, but actually its 38, and the reserveprice is $2400 maybe thats something for you

Post Tue May 02, 2000 11:07 pm

Posts: 8
Thanks Rene. If I put 18" rims on a frame with a 30x neck, will it handle like it should if the neck was 28x? Has anyone ridden that sort of setup? Everything I read talks about how it was necessary to widen the angle for 16 inchers, but I find nothing about this other arraingement. The scare-city of the early frames in good shape makes them so expensive!

Post Thu May 04, 2000 3:26 am

Posts: 582
Location: meridian, id. usa
It should be lighter handling then with the 28 degree neck due to longer trail and larger diameter tire and wheel. change was made due to wobblies at hi speed with 16" wheels or so I been told

Post Thu May 04, 2000 5:58 pm

Posts: 109
Location: holland
thats correct, plus the surface touching the ground of the narrower 18" tire causes less fricture than the wider 16" tire.The guys that built those easy rider like choppers in the sixties put a narrower front wheel in the raked frame, i quess one of the reasons was handling!

[This message has been edited by rein (edited 04 May 2000).]

Post Sun May 14, 2000 4:19 am

Posts: 801
Location: Planet Earth
In the 60's and 70's we put narrow front tires on them for looks only. Most of us didn't know squat about handeling all we cared about was how they looked. If we did know about handeling we would not have extended the front ends to 22" over and kicked the neck out 2" or more. But what the hell it was fun and we were all crazy and were not going to make it past 30 anyway.


Post Fri Jun 02, 2000 2:28 am

Posts: 14
Location: Oslo, Norway

The 28 degree (pre 1941) and 29 deg. (1941-1946) frames both use in-line forks. The reason for the change was the optional 16" rims and fat 5" tyre offered for the model year 1940. This in connection with the 28 deg. rake caused a number of handling problems according to the litterature. (Among them a high speed wobble in worst case). The neck angle was increased 1 degree as a response to these problems. The increased rake gave more trail. More trail means more "self centering" steering and more straight forward stability (and less wobble). It also means heavier steering input to make the bike turn. My 1937 Knuck steers very quick, but some riders of later bikes find it "unstable". I do not think so, I find the later 29 and 30 degree bikes w/ 16" tires heavy and more "unwilling" to make a turn. It's a matter of preference and what you're used to I guess.
In 1946/7 the rake of the frame was increased to 30,3 degrees, but some (all?) of this increase was cancelled out by the "off-line" forks which legs' point slightly "backwards" compared to the fork stem. Why this was done I have never seen an explanation for, maybe it was related to the fact that the Hydra Glide fork was only a few years away? (The rake was not changed for again for the Hydra- and DuoGlide years).
From model year 1941 I have never seen a factory photo showing big twins with 18" rims. Many believe that 16" wheels was "standard" from 1941, with 18" wheels as an no-cost option. In fact the 16" wheel was an option, $5:00 a wheel! (Although this seems to have been a very popular option indeed). The 16" rim did not become "standard" (no extra charge) before the model year 1956.
This means that 18" rims should work fine with 28, 29 and 30 degree necks, given that the right fork is used. What I don't know, but suspect is that a 28 deg. frame with a "offline" fork would be very light steering indeed, and very wobbly too with a 16" tyre! A 30 degree neck with a "in-line" fork should likewise yield a rather heavy steering, and track like a train.
Personally I prefer the 28 degree neck angle for handling, and 4.50" tyres for looks. The extra half inch of rubber fills up those fenders in a pleasant way, gives a trifle softer handling, and increases cornering clearance. All this without ruining handling or looks. What more can you ask?

[This message has been edited by RedKnuck (edited 02 June 2000).]

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