Author Topic: EW twin lever control, is it Bowden?  (Read 5312 times)

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Offline Doug

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EW twin lever control, is it Bowden?
« on: 20 Sep 2009 at 00:12 »
A few pictures of a project to replace the missing longer lever of the twin lever control used on the EW models.


Turning the blank.


Slabbing the sides.


Old and new.


I had to set this up again as I forgot to take a picture while I was milling the radius.


A homemade cutter was used to form the cable slot.


The friction disks are newly made of phenolic. I did not have any originals to go by. They seem to work fine.






An exploded view of the assembly. The spring show is not original, and is far too heavy.




Now questions:

This lever is shown in the illustrated spares lists for the 600EW, as well as I have seen it on many other EWs Douglases of that era. So it is clearly the correct fitment. I have seen them configured as center stud mounting (Douglas) and clasp arm. I have not been able to find any sort of trademark or patent numbers on the two originals that I have had an opportunity to disassemble and examine. But I believe they were sourced through Bowden, same as the clutch and inverted levers on the EW models were. Can anyone say positively that these are Bowden twin lever controls, say from a Bowden catalog illustration? This is not to be confused with a single and twin lever control of Douglas' own manufacture; usually seen as the single lever control used for the magneto on EW models.

The two examples that I examined did not have friction disks. I used phenolic for the one repair, and it worked well enough. Can anyone say what they used originally; fiber, phenolic, leather, etc.?

The exploded view shows a flat wire compression spring that was fitted to the one I repaired. The other example I have is missing the spring entirely. This spring was clearly not original and far too heavy. Can anyone supply the dimensions of the correct spring used? I suspect it is also a flat wire spring, but of a much lighter section. Or it could be some form of disk of Belville washer, though the space seems too great for such.

-Doug


[correct typos. 29May10 -Doug]
« Last Edit: 30 May 2010 at 02:35 by Doug »

Offline Doug

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Re: EW twin lever control, is it Bowden?
« Reply #1 on: 28 Jun 2010 at 02:55 »
It has been identified in a B&B illustrated spares list, used from 1924-28. So not Bowden.

Could still use the specifications for the spring.

-Doug

Offline roy

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Re: EW twin lever control, is it Bowden?
« Reply #2 on: 28 Jun 2010 at 16:02 »
Hi Doug, have attached a couple of photos showing the spring from my twin leaver control fitted to my 350cc EW.
Hope this may help.
Roy.



« Last Edit: 29 Jun 2010 at 10:37 by Dave »

Offline Doug

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Re: EW twin lever control, is it Bowden?
« Reply #3 on: 29 Jun 2010 at 04:33 »
Roy,

Yes that helps. It looks about half to two thirds the thickness of flat wire spring as in the example I worked on.

-Doug