Author Topic: OB douglas 600cc OHV  (Read 2971 times)

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Offline eric007

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OB douglas 600cc OHV
« on: 25 Jan 2014 at 07:42 »
Hi, can any one fill me in on the Douglas OB.

Is this a rare/ valuable/sought after bike or is common.

Are there any issues with getting parts like engine, gearbox any other parts.

Does the the London douglas club carry any parts for this bike.

I know the brakes are a disaster, so from what other bike can I use the wheels from that have drum brakes on them and a sprocket that would still work with the OB.
Can you get these wheels new anywhere or only second hand.

I have been told that parts are very expensive and rebuilding can cost as much as the bike??

Any other running, riding and maintenance issues that can be provided would be much appreciated.



Offline tck

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Re: OB douglas 600cc OHV
« Reply #1 on: 25 Jan 2014 at 14:04 »

Offline Chris

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Re: OB douglas 600cc OHV
« Reply #2 on: 25 Jan 2014 at 18:16 »
Hi Eric
The 600cc overhead valve OB is quite a rare machine and parts are very difficult to find. The LDMCC has few if any spares for this model (see comment below ref. main bearing). Wheels with drum brakes from an SW or similar overhead valve model could be fitted but these are nearly as rare. That said there is no reason why new hubs cannot be made to suit the frame and to which almost any other make of brake drum incorporated. If you wish to retain original "C" section beaded edge rims then new replacements are available from various sources. It appears to have been made for two years only as far as I know. 1924 and 1925. There are differences between the two although whether there was a clear demarcation is unknown. One change seems to have been the use of 36 spoke wheels in 24 and 40 spoke in 25. In common with the other OHV models the crankshaft presents problems in restoration as the shaft is one piece with the conrods fed over from the end, bigend bearings assembled in situ and the bob weights then secured with cotters. Views of this are available on this forum. Timing side main bearings were considered to be obsolete. Solutions to this problem involved grinding down to the correct thickness bearings with the same internal and external diameters but last year a batch of the correct dimension bearings was found in Spain and purchased by the LDMCC.