Quiet on the blog but it has been busy in the workshop with a number of projects progressing. My VSCCS application has been approved in NSW and I am just waiting on a response from the WA Department of Transport. And the picture? Well one of the projects in progress is a rebuild of a 1974 Honda QA50. This is the engine casing after a quick bead blasting.
This makes it very difficult to bleed the brakes but worst of all it is down right dangerous!
I was recently tasked with reconditioning a Honda CB-500 Four that had been left in the weather for a few years. When I saw the bike one of the first things that I noticed was the “front brake reservoir delete” or in simple terms a piece of Tygon tubing with a plug in it. I wasn’t impressed but had seen something similar plenty of times on the motorbike blogs and on race bikes.
Then when I went to bleed the front brake I had one squeeze of the lever (with the bleed nipple open) and then nothing. No brakes. No pumping. Nothing and the tube was still full of fluid. Continue reading Please Don’t Ever Do This!→
As mentioned previously on this blog, this is a motard style conversion of a Honda CRM 250 using a 2007 model Aprilia RS-125 wheels, discs and front brake caliper.
A custom bracket was designed in Solidworks to adapt the radially mounted caliper to the original brake caliper mounting holes. Designing in 3D allowed the part to be simulated (FEA) with heavy braking loads and calculate the factor of safety, stress, strain and distortion.
The APRILIA RS-125 caliper has finally been installed on the Honda CRM-250. The brake system has been bled with a quality DOT-4 brake fluid. It now has a solid feel (though there is some sponginess due to brake hose expansion – this may be replaced with a braided line) and no leeks in the system. So far low-speed testing has been carried out with further testing to come.
Sorry for the lack of updates as I was overseas for a few weeks.
Now to the article, FEA or Finite Element Analysis is an excellent tool for verifying and improving your design. The following image is of a model I have created of the Honda CRM250 front fork with the custom designed adapter bracket and radially mounted caliper from an Aprilia RS-125. Continue reading FEA of Motard Brake Bracket→