Douglas 2 3/4hp - Early Square Brake Rod Bolt + Nut: 1/4" BSC (Stainless Steel)


Douglas 2 3/4hp - Early Square Brake Rod Bolt + Nut: 1/4" BSC (Stainless Steel)

Product no.: 0687 DG234_001

In stock

£6.00
Recommended Retail Price, plus delivery


This is a 1/4 BSC (26tpi) 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.

Consists of bolt, 1/4" x 26tpi BSC nut and two 1/4" washers, all 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 brake 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 for attaching the brake rod to the threaded brake pedal- 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.  The thread is 1/4" BSC (26tpi) and each bolt comes with a nut and two washers also in stainless steel.  If I say so myself they look rather nice, wont rust, and when polished look just like the original nickel (pre-chrome) plating!

Final Note (29/03/18):  I know that Douglas employed some unusual and non-standard threads in this Edwardian period.  I have made this particular bolt in 26tpi (threads per inch) x 1/4" BSC because nuts are available in this size and I was easily able to run a thread cleaning tap of 26pi (BSC) down the female brake pedal thread.  I will use the locknut supplied to run up against the brake pedal to ensure locked correcty.  However I suspect the original bolt may be a weird Douglas 25 tpi x 1/4"  thread, but is not in very good condition.  Please measure your original brake pedal thread/bolt to ensure you know the correct thread before ordering.  It is CNC manufactured in stainless steel

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.

If you think your bolt is a Douglas 25tpi x 1/4" thread - then I have also made a small batch of this alternative type: see Item 0688

 

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