For anyone considering building their own hand break addition. It is not really a conversion if the original brake system remains. There are several factors that must be considered.
The leverage afforded by the hand lever that is acting on the master cylinder.
The size of the bore in the master cylinder.
The size of the bore in the slave cylinder.
The leverage point where the slave cylinder attaches to the foot brake pedal lever.
Lets say that since we are purchasing a new or used master cylinder assembly, we really do not have a lot of control over the lever to master cylinder mechanical advantage (you can however pick one with the bore size that you want) but maybe one of you knows of a master cylinder/lever set up that is more efficient than others.
For example:
For these comparisons we will assume the same force by your hand on the lever.
If we had a master cylinder with a 13mm bore, and a slave cylinder with a 13mm bore, and we change the master cylinder to a smaller bore, say an 11mm, we would now produce more PSI (force) but it would require more travel at the lever to have the same travel at the slave cylinder.
The opposite would of course be true if we increased the master cylinder bore.
The point of attachement to the foot brake pedal lever affects the mechanical advantage between the slave cylinder and the brake pedal lever.
If this attachment point is moved further from the pivot point, the applied force would be greater but again, it would require more travel.
A home made hand brake addition is feasable, but may require a bit of experimentation to get it to work right. Unless of course you are a master mathematician. I am not.
Does anyone know the bore sizes of the manufactured kit that is available. That would be a good starting point.
Another point is that the acuator of the slave cylinder whether a push or a pull type should be positioned so that it is 90 degrees from the foot brake pedal lever in the middle of it's travel.
So, am I nuts?
The leverage afforded by the hand lever that is acting on the master cylinder.
The size of the bore in the master cylinder.
The size of the bore in the slave cylinder.
The leverage point where the slave cylinder attaches to the foot brake pedal lever.
Lets say that since we are purchasing a new or used master cylinder assembly, we really do not have a lot of control over the lever to master cylinder mechanical advantage (you can however pick one with the bore size that you want) but maybe one of you knows of a master cylinder/lever set up that is more efficient than others.
For example:
For these comparisons we will assume the same force by your hand on the lever.
If we had a master cylinder with a 13mm bore, and a slave cylinder with a 13mm bore, and we change the master cylinder to a smaller bore, say an 11mm, we would now produce more PSI (force) but it would require more travel at the lever to have the same travel at the slave cylinder.
The opposite would of course be true if we increased the master cylinder bore.
The point of attachement to the foot brake pedal lever affects the mechanical advantage between the slave cylinder and the brake pedal lever.
If this attachment point is moved further from the pivot point, the applied force would be greater but again, it would require more travel.
A home made hand brake addition is feasable, but may require a bit of experimentation to get it to work right. Unless of course you are a master mathematician. I am not.
Does anyone know the bore sizes of the manufactured kit that is available. That would be a good starting point.
Another point is that the acuator of the slave cylinder whether a push or a pull type should be positioned so that it is 90 degrees from the foot brake pedal lever in the middle of it's travel.
So, am I nuts?
hyea:
