Author Topic: M32 Bent Frame and rear wheel offset  (Read 219 times)

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Offline Hamwic

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  • Location: Hampshire, UK
M32 Bent Frame and rear wheel offset
« on: 03 Sep 2020 at 14:09 »
Hi Folks,

The M32 rebuild continues , and so far so good. However - now we come to the frame. It is an FI prefix.

Judging by the amount of filler in the fuel tank, the machine has taken one or two big swipes in the past. Given it is fitted with Sunbeam forks, this is warning enough that a bit of frame distortion might be expected. When completely stripped, and rear wheel (with soggy tyre) fitted, it can be seen that all is not well!

Whilst the frame is doubtless somewhat awry, the amount of rear wheel offset seems excessive. The spacing between the rear fork ends is 6 1/2" and the current wheel fits nicely without springing the frame either way.

The frame width across the shoulders is 9 1/2", and I would guess that when it comes to pushing it around, that would form the datum point, and presumably the rear fork tubes would be at right angles to the shoulders. It looks like the current wheel would have to be moved over at least 1 inch - possibly more -  to be central with, say, the guard fixing bolt. The stays don't look that far across, but I haven't done a quick-and-dirty measurement yet.

Just in front of the gearbox lug is a gentle kink in the upper tube, and in profile the frame seems to have sagged a little here. I am inclined (ha!) to leave that, as long as I can get the steering axis vertical and central.

So, here's the question. Does anyone have any figures for the frame geometry, or is middle-for-diddle good enough? Has anyone in the UK used any of the Frame Wranglers (e.g. ABBA or Motoliner) in the UK for this age of Douglas frame, and how easily can they be re-aligned?

Many thanks for your views!
« Last Edit: 03 Sep 2020 at 17:29 by Doug »