Author Topic: EW Brake Drums  (Read 287 times)

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Offline hartleys1

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EW Brake Drums
« on: 29 Jul 2018 at 18:50 »
Hi
Can anyone help. The rear brake drum on the 1927 EW sports I am restoring has two deep grooves  in the rear brake drum.
If I press out the bearing outer, will I be able to press the drum off the hub, am I correct in thinking its  pressed on to a spline.
All so is the drum steel or iron. If I can not find a replacement drum. I was considering having it metal sprayed if its not too far gone.
Hope someone can help
Keith Hartley

Offline Doug

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Re: EW Brake Drums
« Reply #1 on: 29 Jul 2018 at 22:37 »
Keith,

If it is original, the brake drum is steel. It could have been changed out for a later hub that had a cast iron drum mounted on a conical spline of a machined steel hub. The original 350EW hub was a tubular steel hub (with the ends swelled for the bearing race) with a spoke flange and a brake drum pressed on each end. The brake drum was the spoke flange on that side. (c1930 the rear drum was replaced by the cast iron type, and then the front drum c1932-33) The 350EW brake drums were available separately, according to the spares list, so it must have been expected that one could press it on or off the hub center section. I have not had one apart to know if they serrated or knurled the joint to give it more grip, but it does suggest they did not solder or braze the hub assembly together. That does not mean that someone later didn't do so, to repair a hub that worked loose. I have re-rimmed these pressed steel drums using large diameter mechanical tubing and welding, but it would probably be just as easy (maybe easier) to spray weld it and re-machine if you have access to that.

-Doug

-Doug

Offline eddie

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Re: EW Brake Drums
« Reply #2 on: 01 Aug 2018 at 09:27 »
Keith,
         Whilst it isn't good that your rear brakedrum is scored - it may still be usable. These days, few riders do great mileages on their old bikes, so shorter lining life should not be a great problem. As for the efficiency of the brake, the rear one doesn't need to be as good as the front one - it is not normally a problem to skid the rear wheel. I would suggest it might be worth cleaning up the drum and trying it as it is, but with a new lining. If it is not effective enough, then you will have to attempt some sort of repair - but bear in mind that those old Douglas steel drums weren't all that rigid in the first place, so welding or metal spraying may cause more distortion.

  Regards,
               Eddie.

P.S. When I relined a Douglas brake for use on my sprinter, I riveted and Araldited the lining on. Use the original 24 hour Araldite - that gives a better bond, and also gives you time to assemble the brake into the drum and apply the brake whilst the Araldite sets (put a strip of polythene sheet around the lining to prevent it gluing to the drum). The bonded assembly will then give you a better brake as the band will truly fit the drum and there will be no gaps between the lining and the brake band that give rise to a 'spongey' brake.

Offline hartleys1

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Re: EW Brake Drums
« Reply #3 on: 01 Aug 2018 at 21:44 »
Thanks for the reply  Eddie. 
As its an ongoing  restoration project I will see if I can get a replacement,
if not, I will  get the wheels rebuilt with the hubs as they are. When I purchased this bike it was a basket case
the rear brake backplate had been damaged and plated which could have contributed to the grooves in the drum
fortunately there was a spare back plate with the bike.
Keith Hartley

 

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