Tuesday, August 13, 2013

Homemade Brake Parts

I spent some time at the lathe experimenting with making some parts for the 1953 Raleigh Sports brakes. This picture shows the cable knarp, levers washers, and brake arm washers I made.  Below I will show how I intend to used these parts.



The cable knarp will allow me to use modern brake cables with the 1953 Raleigh brakes which do not have the cable anchor.  These brakes were intended to be used with the special Raleigh brake cables that were a predetermined length, had soldered cable fittings on both ends, and all the fittings already attached, barrel adjuster etc.  This is a picture showing the cable knarp fitted to the 1953 brake arm.  The knarp was made from 1/4" brass rod which was turned down to fit the brake arm fitting, and drilled and tapped for a 3 x 48 set screw.





 Next are the washers I made to remove all the play in the brake levers.  As I stated before this bike appears to have been ridden a lot.  The brake lever bolt was worn as well as the levers.  There was a lot of slop between the levers and clamp when they were pulled.  These washers were made from Teflon filled Delrin, I cut them very thin (.005 - .008) to fit the space between the lever and the clamp.  They made a big difference in how the brake levers felt after installing, very smooth and precise, no slop.

Cutting the brake lever washers on the lathe.




Washer fitted to brake lever, one on each side.


Next are some Teflon washers made for the brake arms.  The 1953 brakes did not have any washers between the brake arms like the later versions.  The picture below shows the latter type (top of picture) brake arm bushing and and red plastic washer the sits between the brake arms.  The lower bushing is from the 1953 brake, the white washer (Teflon) is what I made to replicate the washer found on the latter brakes.  I do not know if it is necessary but seem like a good idea to reduce the metal on metal contact.  The brakes do not feel as notchy when using it.

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I've notice a significant improvement in how the brakes feel with these extra parts, only when I get it back on the road will I know for sure.
  

4 comments:

  1. Outstanding work. I especially like those cable end knarps you made to fit the Raleigh pattern calipers. Is there any chance you'll be selling sets of these? I'd love to have some on hand for a 1958 Sports I'm repairing currently.

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  2. I have some extra washers, but the knarps would have to be made. I'll be out of town for Thanksgiving, but should be able to get some to you next week. The washers will only work if you have worn parts; otherwise, they will probably not fit. Also the sizing of the knarps will be based on the dimensions of the 1953 brakes I made them for. Hopefully, your 1958 brakes are close to the same size. You can try them and see if they work for you.

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  3. Excellent, may I ask where did you purchase that cable knarp, I'm in need of the exact same one, though I can't find them anywhere.

    Any help would be appreciated, thank you.

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    Replies
    1. I've just realised the knarps are custom made. Sorry about that.

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