Dick Allen Blueprint Frames
Dick Allen and I had a couple of conversations over the course of two or three years about building 'custom' frames for chopped bikes. To be honest I didn't understand about 75% of what he was talking about because he was approaching everything about frame construction from the standpoint of going back and using stock factory frame geometry and then 'chopping' that stock geometry into a new configuration even though he was planning to do this using a completely new, built from scratch chassis.
I had been taught a completely different work method by my old boss where we started with a clean slate, ignoring a lot of the factory frame geometry. Using Dick's method, the frame builders main control point, where everything was measured from, was the intersection point of the backbone and the seat post. On the system I had been taught to use the primary control point was the intersection of the seat post and the seat post cross-member that runs between the lower rails. His system worked from the 'top down' and the system I used worked from the 'bottom up'.
Regardless of the method used, the objective was to basically build a new frame (or modify a stock one) so that it closely resembled a classic Drag Bike, at least in the profile 'stance' from a visual standpoint. Everybody wanted that 'wedge' look.
There is no doubt that a ton of 'Chopper' design was done from the standpoint of building something that was visually appealing but there were practical engineering concepts embodied in these radical looking bikes gleaned from the drag strips. They were long with fairly well raked out necks for high speed stability. The center of gravity was kept very low. Virtually all drag bikes are built around 'rigid' frames.
The easiest way to get that 'look' was to modify a stock frame by 'raising the transmission' so to speak. On a chopper frame the raised tranny mod was a little more involved than what you'd do on a flat-tracker or hill-climber and involved 'chopping' the lower rails right behind the rear tranny mount and then bending the wishbones upwards until they aligned with the stock backbone tube. We did a separate article about this simple modification that can be found HERE.
This customization was probably one of the first things that most frame builders did back in the late fifties and early sixties. Most of us didn't start adding raked necks until around 63 or 64 and by 1965 almost everybody who rode a chopped bike wanted the 'raked' look.
Dick was from what I call the 'true old school' of frame hacking from back in the fifties while I was from the 'new school' of hacksaw wizards and there is a ton of difference between the two schools of thought. Dick's basic concept was to take the geometry from one of his modified stockers and then transfer that to a new line of production frames. Somebody nick-named these frames the 'Blueprint' series.
Somebody said the 'name' came about because the first bike was going to be painted blue but I still think it was because Dick had actually had blueprints made of some drawings he had drawn or had somebody else draft up for the project. I distinctly remember him marking up a print for me at one time in 68 or early 69. I'm pretty sure I still have the dimensions stored away.
Another alternative source of the 'name' may hark back to the old days when most shops had copies of the original Harley frame drawings sold by a whole host of blueprint shops as promotional items. These were the old style prints where the line work was white and the background was dark blue. Most of us in the business just called these 'The Blueprint' when referring to the factory frame alignment dimensions for a project frame.
Most folks are probably already familiar with this drawing as it's been reproduced by dozens of print shops over the years and some folks are even selling these 'recent' Xerographic versions on eBay that are barely readable and way out of scale. I 'redrew' the original of this print and 'modernized' it a bit for use with the old Hossfeld benders in 1964 using ink on vellum and a Leroy set to do the lettering and sold copies of my own to shops for several years and then in 1976 I converted it to modern CAD format using an old Auto-Trol system. In 1986 I converted that over to the Auto-Cad format. I used to give these copies away for free until we started seeing them being sold on eBay so we took them down from the free download section of the site.
This is still our most popular drawing and to a fairly large extent shops use it as a 'baseline' for doing their own custom work since the dimensions are extremely accurate but I'm getting off subject.
The first 'Blueprint' bike was supposedly built for Freaky Fred Williams and was a big hit. The image below was taken from the Chris Kallas site and looks to be a scan from a magazine article about the bike in one of it's later incarnations.
The bike looks much larger in this photo than it actually was and another snapshot taken at a show in it's original configuration gives a better idea of the proportions when it's seen viewed from a different vantage point.
This bike is considered by many to be the first completely custom built chopper that used what was basically a mass-produced frame. Unfortunately Allen never really went into full production. Some say that he only built three frames while other friends have told me that he built several dozen 'semi-production' frames in several iterations that were based on this original prototype. He did build three almost identical bikes to completion but I haven't found any pictures yet.
Here's another photo I lifted from the motorcycle-art site and it shows Bruce Parrish in the process of preparing one of the 'Blueprint' frames for painting. It's dated April 1973.
Note that this is not Fred's frame from the previous pictures. William's bike had 'sidecar hoops' welded to the down tubes that were used for highway pegs. I've also seen one 'blueprint' frame that had the old original style down tubes that bent into the lower rails with two short bends instead of the single large radius bend seen here.
To be honest I never could get my mind wrapped around Dick's theory of frame building so I just trudged along for the next forty years building what I was used to. A few weeks ago however somebody pointed out that Irish Rich had run across a frame that is most likely one of Allen's early work. The complete story of his 'find' is on his blog located HERE.
Here's a snapshot taken from his site and it clearly shows all of the typical Allen frame 'hallmarks'.
Note the stock style rear axle 'slots' and how high they are from the ground level. Notice that the motor mounts look to be on a 2-degree slant, one of Dick's favorite tricks. The fabrication technique used on the mount plates are almost identical to that seen on the 'Blueprint frame as is the rear tranny mount.
After seeing this I decided that I had better go back into some of my boxes in the storage shed and see if I could find my old original notes made back in 69 concerning Dick's frame building geometry. It suddenly dawned on me that after 45-years I was now smart enough to finally begin to understand what he tried to tell me long ago.
Update 10-24-14. I did find almost all of my original notes and sketches on Dick's frame concept. They're dated 1969 and I'll start working on a drawing to post in the next few weeks. I'm completely convinced that the frame Rich now has is one of Allen's 'Blueprint' series but I don't know if it's an early version or a later version. The down tube braces don't look like something Dick would have built and the lack of a steering tube gusset is also something Allen would not leave out.
Here is a drawing, as promised, taken from the notes I had made in 69. I didn't add a lot of details but did put in some of the major dimensions. It's very close in concept to the frame pictured above with some minor variations.
Basically this ends up being a frame with an average of close to 2-inches of up-stretch, 2-inches of out stretch at the neck and another 2-inches out in the rear. The axle is moved up an inch over stock (lowers the frame's ground clearance). The entire motor/tranny is canted 2 degrees over stock, measured from a point revolving around the crank center. In effect you get a 'raised tranny' frame.
My notes indicated that the material was .095 wall 4130 and I had labeled the original sketch the 'Easy Frame'. I can't remember if that's what Dick was calling it or just a note I made about it being an 'easy' one for builders in general. Also keep in mind that these old plans were designed around Panheads so no way would a modern Evo fit under the backbone.
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