Douglas 2 3/4hp - Early Square Brake Rod Bolt - Alternative 25tpi Douglas Thread (Stainless Steel)


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Douglas 2 3/4hp - Early Square Brake Rod Bolt - Alternative 25tpi Douglas Thread (Stainless Steel)

Product no.: 0688 DG234_002

In stock

£5.50
Recommended Retail Price, plus delivery


This is a shouldered bolt of 1.00" shaft length, with the distinctive shouldered square head, of the type used on brake assemblies of early Douglas 2 3/4hp models.  It is intended to feed through the brake rod square clevis - and then screw into the original Douglas brake pedal, then a locknut is used on the opposite side to retain it. This item is an alternative to item 0687 - in that it has a Douglas 25tpi thread instead of 26tpi BSC thread used on item 687.  Please measure your original brake pedal thread/bolt to ensure you know the correct thread before ordering.  It is CNC manufactured in stainless steel

I have made a small batch of these bolts as part of the restoration of my own Douglas 2 3/4 hp model, of which I am building as a 'loose' copy of a sports/racing version of this model - a Works model of which Douglas won the Isle of Man Junior TT with in 1912.

I copied this bolt from an original item which was part of a very rusty but original early Douglas front brake assembly - which I am almost certain was of the type of assembly fitted to the 1910-1912 models, to the front downtube.  I have seen a very similar assembly and brake pedal fitted to period photos of this model - where it was not uncommon to have a two sets of footrests, the normal set just in front of the two speed countershaft, and another forward positioned assembly mounted at the base of the front down tube.  

When purchased this front assembly was very rusty and dilapidated - but looked original and unmolested.  The assembly included the brake pedal (see accompanying photos), original Douglas brake positioning lock ring and square headed bolt for that locking (see Item 0689/690) and what looked to be original but very rusty brake rod with square clevis and square headed bolt - which is the item shown here.

Although the square headed bolt was very dilapidated, I was able to de-rust it and used it as a template for CNC machining a copy in stainless steel, including lipped square head, which has been milled from round bar. 

Note:  see also item 0687 description.  When I copied the original Douglas bolt I used as a pattern - it was 1/4" x 26tpi BSC - which is Item 0687.  However, some bolts of this period look to have been 25tpi (see also the shorter brake pedal adjusting ring bolt - item 0688, which is also of 25 tpi is an example of this).  But I made a small batch of the longer 'item 0687' type brake rod bolts - but with the Douglas type 25 tpi x 1/4" thread instead, in case you believe your bike is fitted with this thread.

if you are not sure (the difference between 26tpi and 25tpi is very close) and have the original bolt - then try and run a 1/4 BSC nut down the thread of your original bolt - if it tightens up as you start, it may be a 25tpi bolt.  Alternatively - hold a 1/4BSC bolt up against the thread of your original douglas bolt - if one thread does not exactly sit in the other, this is another way to tell.

Unfortunately, I do not offer 25 tpi Douglas thread nuts to fit this bolt - so this listing is for the bolt only.  As this bolt is intended to feed through the Douglas 2 3/4hp brake rod clevis and then screw into the original Douglas brake pedal, you will need to keep hold of your original locknut if you still have it! 

 

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