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General => Douglas Motorcycles - General Discussion => Topic started by: podge on 20 May 2010 at 14:23

Title: Primary Drive
Post by: podge on 20 May 2010 at 14:23
Hi Guys

The Brooklands Douglas Project has run into a dilemma concerning the primary drive. The engine sprocket takes 1/2 inch x 5/6 inch chain, whereas the large gearbox sprocket is 5/8 inch x 1/4 inch. We either have to change the engine sprocket or the gearbox sprocket, although the latter is easier. Can anyone help to provide the right spare for either of these?

Regards

Paul
Title: Re: Primary Drive
Post by: eddie on 21 May 2010 at 05:56
Paul,
        Most bearing stockists can supply 1/2" x 5/16" platewheels with the required number of teeth and a pilot 1" bore. You will then only need to get the centre bored out to the correct diameter and the six holes drilled for the shock absorber springs/plungers.
                               Regards,
                                         Eddie.
Title: Re: Primary Drive
Post by: podge on 22 May 2010 at 09:25
Eddie

Thank you for your as ever most useful advice. Changing the gearbox sprocket seems the best solution to the problem. Do you by chance have a reference for such a supplier?

Regards

Paul
Title: Re: Primary Drive
Post by: oily bloke on 22 May 2010 at 12:09
Hi Paul

I have used these people a few time to make sprockets for my Triumph (sorry) sprint bike and found them very helpfull and professional.

http://www.sprockets.stenor.com (http://www.sprockets.stenor.com)

Hope this helps

Cheers

Andrew
Title: Re: Primary Drive
Post by: eddie on 22 May 2010 at 13:04
Paul,
         SCH Bearings of Greatbridge Business Park, Budds Lane, Romsey, Hants. SO51 0HA  Tel 01794 830377 have always been able to help when I've needed sprockets. As mentioned in my previous reply, if you ask for a platewheel you will get a plain disc steel sprocket - if you ask for a sprocket, it will come with a boss that will then have to be machined off.
                   Good luck with the project,
                                          Regards,
                                                Eddie.
Title: Re: Primary Drive
Post by: podge on 23 May 2010 at 12:04
Eddie and Andrew

Thamks for the valuable references. Your help is much appreciated.

Cheers

Paul