Monday, February 27, 2006

Homemade Ti cantilever return springs

So, the second part of my Carbon Cantilever project is to make the titanium cantilever return springs. I know that this wont drop much weight as the standard steel springs weigh in at about 9 grams a pair. But, I want these brakes to be as light as possible without giving up functionality. Also, because my carbon arms are a different dimension than anything else out there, I was going to have make some custom springs anyway, why not make them out of titanium?

I didnt invent titanium springs or how to make them. I found a post on weight weenies that showed how to make a ti spring out of a titanium spoke for use on a front derailleur (see link below). After seeing this, I thought I could do the same thing for my carbon brakes. I ordered some titanium springs in 2.0 width and received them yesterday. This morning I went to work.

Items you'll need for this project are: a benchmounted vise, 1 needle nose Vice Grips, 1 standard Vice Grips, a titanium spoke, a wire coat hanger, some wire cutters and a 3/8" bolt to wrap around.

I used a 3/8" bolt and it seems to have worked well. I made my first set a little too short (as I matched the empella froggleggs spring identically--or pretty close and my brakes dont have the same dimensions as the Empella's). So I made another pair.

The coat hanger is used to hold one end of the titanoium spoke. Also, I'd recommend practicing making these with a length of coat hanger as coat hangers are generally free and titanium spokes generally are not--and youre probably going to screw the first one up a little, I did.

You'll need to make two coathanger eyelets that hold the titanium spoke. One that wraps one direction and another than wraps the other direction. Due to the left and rind sidedness of the springs.

I decided to wrap the titanium around the bolt differently for each side to determine which spring tension was best. One was wrapped 3x around the bolt (like the empella's) and the other is 2x around. I'll test to see which one I like better.

Total weight came in at 5 grams for the pair compared to the 9 grams for the standard springs. While, this only saved 4 grams, part of the reason is that my springs are larger to accomodate the shape of my carbon arms.

The Weight Weenie thread that shows how to make a ti spring for a front der.


Anonymous said...

I think it is pretty sweet that you're making the best of your free time. Mine is usually spent watching CNN.


Jeremy Burlingame said...

thanks mate, yeah, ive been enjoying myself.