David,
You mentioned "replacement shoes" - are you referring to current VOC Spares stock, or something else?
And a prior post in this thread alluded to some other shoes becoming available, but no details were given.
And a thought about the balance beam - It seems to me that it would equalize ("balance") the force on both sides, i.e. correct for some maladjustment so both sides of the brakes operated at about the same time and with approximately equal force.
And have you found some new brake lining material, better than the "Green Gripper Woven" material you mentioned recently?
John,
I did not find the reference, but I was probably talking about the Club shoes provided by Godet as replacement shoes. The stock Vincent shoes I have examined are laughably inadequate. I went through about 15 shoes and all of them were bent or severely deformed (meaning they were not necessarily bent but the arc of the shoe had deformed inward.) The good news is that they are so soft you can put them in the vise and straighten them out if they are bent. The deformation is more difficult because you have to restore the original arc.
I am a little surprised that some feel the shoes are fine. I would have thought that Trevor's front brake demonstrator, where you can watch the shoe deform as you apply the brakes would have been persuasive. Additionally, having review all of the brake mod articles done in the last 60 years I can only note that none of the mods have significantly improved the brakes. In other words, if all those mods were applied to Trevor's demonstrator, the front shoes would most likely continue to flex under braking. Finally, the only component in the Vincent brake system that has not been modified has been the brake shoes.
From a more modern point of view, I would expect to see the brake shoes used for rear brakes on modern motorcycles to have copied the Vincent brake shoe design if it were truly on the cutting edge of motorcycle design. That is not the case. Modern brake shoes are high pressure die cast design with almost 100% more material. Thus, I think the interest in a more robust brake shoe is well deserved.
There are some shoes other than Godet shoes being designed, but they have not been produced yet. I was hoping to use some new shoes to test out some modern linings. There may be linings that offer superior stopping performance to the Green Gripper, but they may not be suitable for other reasons. As a result, I think it is safest to use what has been tested. By the numbers, Green Gripper is superior to AM4 and it seems to me that AM4 performance should be the minimum performance that I would want to see. There are modern lining that offer more than double the coefficient of friction of AM4, but they need some careful testing. Increasing the coefficient of friction is a non-linear function. Historically, this increase produces much more fade due to the high heat generated by the high friction. Non-linear increases can produce grabbing, squealing and lots of dust.
I have some new brake shoes that I have nearly finished machining. When they are done I will clad them with .61 coefficient of friction lining. The AM4 is .44 and Green Gripper is .53.
David