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General => Douglas Motorcycles - General Discussion => Topic started by: Edin on 17 Feb 2013 at 18:14

Title: Douglas 1934 model Z - 4 speed gearbox
Post by: Edin on 17 Feb 2013 at 18:14
Hej all
I am restoring/rebuild a model Z from 1934 - from a very poor condition - and need some help.
The bike was fitted with Norton gearbox and clutch,- and when I try to make it back to original shape,- there was some unexpected problems with align from primary and secundary chain.
I have some Douglas 4 speed gearboxes i many pieces ,- but with different kickstarting mechanism
One of them with ordinary tooth sector - another with Bendix starting mechanism
With assemblet gearbox,- the sprocket/chainwheel for both primary and secondary chain was about 10-14 mm out of line with engine and rear wheel (too far-away from gearbox left side)
Can someone please help and explain whats wrong.
Are there made different 4 speed gearboxes for Douglas,- on another of my Douglas four speed gearboxes,- the distance from gearbox to chainwheel is correct and about 12mm less.
I would be grateful for any help and advice
Enclosed some foto of the project
Regards Edin DK

(https://www.douglasmotorcycles.net/aa-files/images/edin/2013/douglas-1934-model-z-01-750.jpg)

(https://www.douglasmotorcycles.net/aa-files/images/edin/2013/douglas-1934-model-z-02-750.jpg)

(https://www.douglasmotorcycles.net/aa-files/images/edin/2013/douglas-1934-model-z-03-750.jpg)
Title: Re: Douglas 1934 model Z - 4 speed gearbox
Post by: eddie on 18 Feb 2013 at 06:32
Hi Edin,
            Many years ago I acquired a 4 speed box that I eventualy swapped for other Douggie bits I needed. When I quoted the gearbox number, I was told "that's one with a longer mainshaft for a Powerflow" - so it would seem there were at least 2 options on mainshaft length.
     Hope this helps,
           Regards,
                         Eddie.
Title: Re: Douglas 1934 model Z - 4 speed gearbox
Post by: Edin on 18 Feb 2013 at 07:11
Hej Eddie
Thanks for your help,- just what i needed
Regards Edin DK
Title: Re: Douglas 1934 model Z - 4 speed gearbox
Post by: Doug on 18 Feb 2013 at 17:21
Edin,

On the earlier 3-speed gearboxes there were short and long mainshafts depending on if it was a 250-350cc or a 500-600cc. It is probably the same for the 4-speed gearboxes as the heavyweight engines are wider than the lightweights.

Doug