Nick's instructions are here.
BSA A7 & A10 1959 Onwards
Converting Cable Operated Rear Brake to Rod Operation
(Down Wards Rear Brake Arm & Full Width Cast Iron Hub))
Introduction:
This is a guide for those of us that have limit resources and who have basic hand skills will be able to produce this conversion very simply and with only one trip for welding.
The guidance is for A7 & A10 I can see no reason why that it will not work on B31 & B33 and also A7 & A10 with the brake arm upwards.
Items Required: Item Description Comments
1 Rear Brake Arm 40 – 6041 1962 A50/65 & C15 Draganfly Spares 01986 - 894798 & Lightning Spares
2 Crossover Shaft Arm 68-7020 1962 A50/65 (Clevis Cable End) Draganfly Spares
www.draganfly.co.uk3 Steel Pipe Dia 21.32mm Wall Thickness 2.62mm Internal 16mm Length 4.7/8’’ (130mm)
4 Brake Rod Connection Bracket 1 ¾’’ x 7/8’’ x 3/16’’ – 40 x 22 x 4.5mm
5 S/Steel Brake Rod ¼’’ X 24’’ Long Screwed BSF for 6’’ Lightning Spares 0161- 9693850
6 S/Steel Brake Rod Trunnion 7/16’’
www.lightning-spares.co.uk7 S/Steel Brake Rod Adjuster Knurled Thread ¼’’ BSF As above
8 S/Steel 1 x ¼’’ BSF Nut & Washer As above
9 S/Steel ¼’’ Compression Spring 3’’ As above
10 S/Steel 1 x Split Pin & 1 x ¼’’ Washer As above
11 S/Steel Bolt 1.1/4’’ x ¼’’ plus Washer for Shaft Arm As above
Crossover Shaft Z Arm :
1. Cut square one end of pipe, file and remove burrs inside.
2. Now cut to length 4.7/8’’ (123mm) again file and remove burrs inside.
3. From one end measure 2.1/2’’(63mm) this fits on to the arm and cut at 450
4. The shorter piece 2.3/8’’ (60mm) form the right angle (top).
Crossover Shaft Z Arm End Connection Plate:
1. Cut to dimension 1 ¾’’ x 7/8’’ x 3/16’’ – (40mm x 22mm x 4.5mm)
2. Mark centre line through plate and come in 3/8’’ 10mm and drill 5mm hole.
3. Cut and file plate into shape that is required to fit on the end of the pipe.
Crossover Shaft Arm:
1. If possible grind cable end round so it will push fit into the pipe, if not it’s a file.
2. By doing this it will keep in the right position when being welded and also when its on the crossover shaft for checking for fit.
Assembly of Z Arm Ready for Welding
1. Check arm on the shaft that you have clearance to oil tank and pipes, use marker pen or tipex (correction fluid) to make sure that every thing is in the right directions.
2. Rod connection bracket if the welder puts the Z arm in the vice with the pinch bolt parallel to the jaw the arm will be slightly towards the right, connection bracket now needs to be horizontal.
Rear Brake Arm:
1. The only brake arm that I could find that would suit was from a BSA A65, which can be purchased new, the only problem is that the stepped hole is to large.
2. Fill weld the hole and then drill 9mm hole in the centre.
3. When the hole has been drilled the boss area needs to be a 3/16’’
(4.5mm) thickness, as same as the original brake arm.
4. Reducing of the boss area will enable a full nut to be fitted.
5. With the brake arm in the vice with the offset facing you it needs to be at about 10/11 O’clock position so when the brake is applied the arm does not go past vertical, file square to vice jaws this will give a good guide.
6. With a tapered 3/8’’ (10mm) square file (fig 7) carefully file the hole square.
Note: The original brake arm is a tight fit, there is a very small shoulder on the spindle that the arm butts up against, if you make the hole to big the arm will then butt up against the brake plate.
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