Rear wheel driving sprocket on early 2-speeders

[Deleted User]

The rear wheel driving spocket on the early two-speeders (part no. 364) is integral with the rear brake drum. This means that you probably have to replace the whole unit when the sprocket wears out.

The sprocket on my 1912 Scott is quite worn. It is probably useable for a while, but should be replaced. The brake drum surface is also worn and pitted. Are there any remedies for this unit?

I doubt very much whether anyone has a new sprocket unit lying around waiting for a new needy owner, but it is worth a try.

The rear brake consists of a brake shoe onto which, a fairly soft brake block is fastened, working on the inside of the drum. The brake block is ca. 7/16″ thick, and although a modern brake lining obviously can be vulcanized on, it probably will not work properly.
My brake block is approaching the end of life.

This is my first two-speeder, and I need help and advice from experienced and knowledgeable club members.

Kind regards,

Carl

[BRIAN MARSHALL]

Hello Carl.
Perhaps your best bet would be to find one of Tom Ward’s rear brake conversions cast aside by someone wanting to take their early two-speeder back to standard specification. The Ward rear brake is a contracting band operating on the outside surface instead of the worn inner surface, and is a much better brake than the Scott original. Try an advert in the next available Yowl.
Best wishes,
Brian

[Deleted User]

Hello Brian,

Good and practical advice from you as usual – especially if the bike will be used extensively in modern traffic. However, I will stubbornly try to keep the original system, and my problem is not only related to the brake, but also to the integral sprocket. Has anyone tried to solve this problem before without reconstructing the system? Is there a sprocket and/or brake block hidden away somewhere or any secret remedies to the problem?

Kind regards,

Carl

[Deleted User]

Hi Carl I am not familiar with 1912 rear sprockets, but am quite familiar with having sprockets retoothed. The old toothed section is removed and a ring welded on the the sprocket teeth recut on a gear shaper. If the man who does it knows what he is doing, it looks like a new part. I just had one done for an old BSA and I was well pleased with it.
You can send direct to this contact if you wish, but before I sent it, I blast cleaned it thoroughly and on return I had it phosphate treated for long term corrosion resistance.
This man can also retooth almost any sprocket including 3 speeder final drive sprockets
John Hemming Engineering
Unit M, The Timber Yard,
Bucknell,
Shropshire SY7 0EL
Tel 01547 530 759

Kind Regards
Roger

[Deleted User]

I have spoken to Ken Lack today. He says that there exists a pattern for the sprocket. The last time he heard about it, it was in the custody of a Brian O’Toole. Does anyone know the whereabouts and/or contact details for mr. O’Toole?

Kind regards, 🙂
Carl

[lewis onions]

Last seen on a camel c/o Syrian desert.

[Deleted User]

As far as I know, Lewis, Peter O’Toole is no foundryman. But, then again, I may be wrong!

cheers!

Carl 😯

[BRIAN MARSHALL]

But BRIAN O’Toole most certainly IS a foundry expert, with many contacts in the motor industry for manufacturing replacement components. The membership secretary should be able to give you his phone number. He used to be very active on the Scott scene, buying up lots of projects and assorted components, but I haven’t heard from him for quite a while. I hope he is OK.
Brian

[Deleted User]

I am now having a new sprocket made in malleable iron. A pattern has been found, and I am planning to have 4 made – one for myself and 3 for the SOC Spares scheme. It is too early to quote a price, but the price will obviously decrease if more are made. If somebody is interested, please let me know asap. I will be at Abbottsholme, and will probably have more information then.

Cheers,

Carl 😀

[Deleted User]

Thanks to generous help from Laurie Erwood, 4 castings of the early rear wheel sprockets have now been made. 3 for SOC spares and one for myself. Laurie will bring them to Abbotsholme on Sunday 28th August.

Machining will be done later. However, in order to do this correctly, a sample/pattern would be extremely useful. If one of the SOC members has a rear wheel sprocket in original or close to original condition (1911-1919 vintage) which can be lent out as a sample, to me, to Roger Moss or to Graham Moag this autumn, it would really be appreciated.

I look forward to seeing all of you at Abbotsholme next weekend.

Carl

[lewis onions]

Hello Carl

The rear whell of my 1911 is out at present – I will bring it to Abbotsholme – it will be good to see if it is the same as I am not sure whether the sproket size changed in later bikes. You will have to excuse the Japanese bearings in the hub!

Lewis

[Deleted User]

Thank you, Lewis! It will be interesting to compare with the data I have already. I will bring photographs and measures. The rear sprocket should either have 66 teeth (solo machines) or 75 teeth (sidecar machines) according to the instruction book. My old sprocket has 75 teeth, but to approach solo gearing, a previous owner has installed a larger outgoing gearbox-sprocket.
Kind regards,

Carl

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