MrBugatti

I found these bearings in the wheels and casters aisle at my local Bunnings.



They are 35mm O/D 11mm wide with a 15mm I/D

These are the perfect size for front postie bike wheels which only use a 35x11x12mm bearing as standard.

The standard 12mm spindle is no good for a cyclekart as it will easily bend when only supported from one end. So increasing the spindle size is necessary. By using these bearings the spindle size can be increased to15mm, substantially stronger than the original. This allows you to use an M15 high tensile bolt, which is plenty strong enough and relatively easy to source.

I looked for these bearings on the Bunnings website so that I could post a link to them but could not find them listed there but might be worth a trip to your local Bunnings if you need to source bearings.

After a bit of a search I finally found and purchased some springs today from Northern Springworks in Gawler, South Australia, $45 each. dimensions 610mm centre to centre, 40mm wide, 6mm thick, 125 mm bow, with nylon bushes to suit 1/2 inch bolts, see attached photo.

After a bit of a search I finally found and purchased some springs today from Northern Springworks in Gawler, South Australia, $45 each. dimensions 610mm centre to centre, 40mm wide, 6mm thick, 125 mm bow, with nylon bushes to suit 1/2 inch bolts, see attached photo.

Found some info on the heat treating stages required for making leaf springs so leaving it here for later...

• Steps in making a leaf spring without special equipment
  
• Anneal the steel strip raw material - Heat to approx 800~850°C (cherry to bright red) and allow to cool s-l-o-w-l-y in air.
  
• Cut, machine and form and shape the individual leaves.
  
• Test assemble the complete spring assembly.
  
• When satisfied, disassemble the spring again and harden the leaves (individually). [Heat to approx 820°C (bright red) and quench in oil].
  
• Clean the surface with steel wool or similar to see the colours clearly when tempering (next).
  
• Temper the leaves. [Heat to approx 320°C (dark blue/grey) and quench in oil].
  
• Clean the leaves, and paint or apply final finish if desired.
  
• Assemble the spring.