Removal and reinstallation (swap) of Campy crank bearing 6805 5 mm

Wheels of Happiness

The Pinarello bike all ready had lateral movement on the crank,  While Mario serviced this about 6 months ago, long time has a way of saying the bearing is old and needs replacement.   From the video, I saw that the crank need 6805 (24 mm) but has to be 6 mm. Most that are available online is  7 mm.  The original bearing is Cult and cost $100      

My first problems are the tools:  the 10 mm removal tool, the puller and the press fit.  No hammer, no drift as per video.

1. For the 10 mm hex, my difficulty was that the short end will not fit into the crank so it has to be a long arm to fit  None is available at DIY or Wigo.  So I thought of fitting a 10 mm socket at the short end of the hex and use that to remove the nut.   And so I did.

2.  For removal and installation, I had the bike mechanic nearby do the job  Paid him P100.00.  I did not have to buy the tools

Lateral movement solved

More on quad vs dual brake system for MTB

Wheels of Happiness

Rizal Philippines

4.09.2021

Remembering the fall of Bataan.    (Reminds us that we should not give up Philippine territories - which we are doing without putting up a fight)

More on quad piston brakes:

1.  Marginal gains can be achieved of only 10%;

2.  We base on the surface area of brake pads, the  difference between the dual and quad brake piston is roughly 1 cm only.  Since we base the brake torque on surface area, surely gains can be marginal.

Quad vs dual piston brakes.

3.  The formula for calculating brake force (torque)

Calculate the torque that the force of the road causes about the axle. Because torque equals force times its distance from the point of rotation, the torque equals the force of the road times the radius of the wheel. The force of the road is the equal and opposite torsional reaction caused by the brakes, so the braking torque is equal in magnitude and opposite in direction to the torque exerted by the road. If the Jeep's wheel has a radius of 0.25 meters, the braking torque equals 8,000 N * 0.25 m, or 2,000 Newton-meters.

Let us assume we need a force of 1,000 nM to stop the bike:

       For   160 mm.   R =  80 mm     .08 meter   =    80 nM

       For    180 mm   R=   90 mm      09 meter   =    90 nM

       For    203 mm   R = 101.5        .10 meter   =  100 nM

Unless we can show we are increasing the  force being applied (unless the brake lever increases in size, then the force is seen to be constant.    The pad force would be constant unless the area of the piston has increased.