Author Topic: Dragonfly Front Brake  (Read 2949 times)

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Offline Richmond

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Dragonfly Front Brake
« on: 13 Feb 2013 at 09:54 »
Hi
I have recently acquired a 1954 Dragonfly and this is my first post. I have just converted to 12volt positive earth and fitted the Maplin ignition kit. Now that she starts and runs it would be prudent to make sure the breaking is up to standard.
I have a significant amount of freeplay on the front brake backplate but am unsure as to what action to take. Is it a feature of the model? Any guidance please.

Online eddie

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Re: Dragonfly Front Brake
« Reply #1 on: 13 Feb 2013 at 12:41 »
Hello Richmond,
                         Firstly, may I question whether you really have a 1954 Dragonfly? Whilst this model did appear in 1954 for the Motorcycle Show, they were not made available to the public until about half way through 1955. Also,'Douglas Dragonfly' trips off the tongue and a lot of people think any Douglas is a 'Dragonfly'. The earlier model - the Mark 5, and the early Dragonfly had Douglas brakes - later Dragonflies had British hub brakes. The easiest way to differentiate is to check out the back plate - the Douglas brakes had a cast alloy back plate, where as the British Hub had a steel backplate with a pressed alloy cover. The cast alloy backplate of the earlier model has a reputation for premature wear if it is not kept adequately greased. The only way of restoring the original fit is to have the 'top hat' shell bearing ground to a good finish, then bore out the backplate and clean up the faces, then sleeve and shim up the bearing to suit.
     If you provide a frame number, we can identify your machine more exactly, and may even be able to give the date it was dispatched from the factory.
     Regarding your conversion to 12 volt and the fitting of a Maplin ignition kit - this will overcome some of the problems with the Miller ignition system, but the main problem centres on the wear in the distributor bearings, and also the fact that Miller points are now hard to obtain.

    Regards,
                   Eddie.

Offline Richmond

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Re: Dragonfly Front Brake
« Reply #2 on: 13 Feb 2013 at 13:22 »
Thanks Eddie

Oops actually its a 1956 all numbers 1226/6, I have no idea where 54 came from, one of those senior moments. Yes the brakes are Douglas. I realise the points are shall we say rare, that was one of the reason for the kit as it reduces the current at the points (that's the theory).

Since my post I have experimented in fitting a shim around the bush and a Fosters ally can seems to fit the bill ! I assume that the only movement on the bush is slight on suspension so hopefully the shim will fit the bill.

Rich

Offline Reg

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Re: Dragonfly Front Brake
« Reply #3 on: 13 Feb 2013 at 17:11 »
Rich,
        Just a few words to enlighten you on the date of manufacture of your Dragonfly. Your particular model with number 1226 and finished in the stone and green colour scheme was originally sent to Scottish dealers J.R.Alexander from the factory here in Kingswood, Bristol on 7th October 1955. It is probable the bike was not sold until 1956 when it became officially first registered for the road.

Reg

Offline Richmond

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Re: Dragonfly Front Brake
« Reply #4 on: 14 Feb 2013 at 09:41 »
Reg
Thanks for the interesting information on the trusty machine.

Regards 
Rich