Bend a hook in the end of the rod and slip it under the loop in the wire. You can make the hook longer than you need and trim it later to size.
I put the Campy spring by the bolt so you can look at it while you are making the spring.
As you are winding the spring try to get the windings close to eachother and tight. You will have to count how many winds it takes to make your spring.
As you get to the last wind you will want to wind past the point where the campy one stops winding because of spring back.
When you turn the spring and look through the hole you can use the clock method to measure the relationship of the start of the spring and the end.
If you make it just like the steel Campy spring and the Ti spring is not as strong you can change the relationship of the start and the end. But you will have to wind up the spring more when you instal it. If you wind it up to much the iside dia becomes to small and it binds.
I used 1.5 mm dia. annealed Ti rod from this place.
http://www.smallparts.com/products/desc ... s/ZRTT.cfm
As Madcow said the spring i made was less strong than the Campy one but I wanted it to be less strong. I think the original one is way to strong. All the spring needs to do is push the chain off the big ring and mine does it fine. You can use a 1.5 or 2.0 Ti spoke. The spokes aren't annealed so they should be stronger and more difficult to bend.
Putting the spring back on the derraileur can be a challenge. You can use a piece of tubing on the end of the spring to help wind it up and hold it in place while you push the pivot pin through. I'm not sure if swearing helps but you might want to be alone while doing this.
Feel free to ask more questions or pm me. This isn't that hard. Buy more rod than you will need so if you don't like the first one you can make another. Or you can send me your part and I can put one on for you.
EDIT: I just wound a 2.0 spring and it was to small in dia. So I wound another around a 7mm bolt and it came out right at eight mm inside dia.
http://weightweenies.starbike.com/forum ... ght=spring
popawheelie wrote:I weighed the Campy springs (5.3) and the Ti one (3.0). Almost half the weight.
If it has ~same amount of material cubic capacity, it's not hard to quess that. Ti weight like ~60% of steel and you get 57%...
But getting 2.3g of my bike?...I'll keep my std. spring.
It's alot of work and expensive. You need a whole new Record derraileur, those carbon pulleys, and the carbon plate just to start.
There are two springs in it also.
then there is the shifters? There's alot of steel in them.