Making your own Ti springs

Discuss light weight issues concerning road bikes & parts.
popawheelie
Posts: 1021
Joined: Thu Sep 26, 2002 3:42 pm
Location: in Colorado

by popawheelie

I've made a few springs for Campy front derraileurs and wanted to show you how I did it. If you need more info just ask. The first pic is an overview of the bolt i use to wrap the spring around and the wire to hold the end of the spring. The bolt is 6mm in dia. The Campy springs inside dia is 8mm. When you wrap the rod around the bolt you want to pull on the rod as you wrap. This makes the rod bend closer the the bolt as you wrap. Even though you wrap it tightly around the 6mm bolt it will spring back when you let go. It should be around 8mm inside dia. when you are done. This is called springback. As you can see the wire has a loop in the end and wraps around the bolt a few times before it goes over to be clamped.
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.
Attachments
trip 055 (2).jpg
trip 056 (2).jpg
trip 060 (2).jpg
trip 058 (3).jpg
Last edited by popawheelie on Sun Jan 15, 2006 5:15 am, edited 1 time in total.

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TunedCannondaleR700
Posts: 341
Joined: Wed May 18, 2005 10:37 am
Location: California

by TunedCannondaleR700

How much weight is saved from switching to a handmade Ti spring from the original steel spring :?:
Cannondale is quite simply the best

by Weenie


popawheelie
Posts: 1021
Joined: Thu Sep 26, 2002 3:42 pm
Location: in Colorado

by popawheelie

I don't have the weight for just the spring. I worked on Madcows derraileur and got it down to 49.8 grams for a Record. The spring was just part of the diet I put it on.
http://weightweenies.starbike.com/forum ... ght=spring

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Boonen
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Joined: Thu Aug 05, 2004 7:33 am
Location: Europe

by Boonen

Thank you very much for the thorough description of what you did popawheelie, very well explained! :thumbup: As soon as I get a record fd I'm going to try this out :D

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col hicks
Posts: 987
Joined: Tue Mar 15, 2005 8:59 pm
Location: u.k

by col hicks

:D thanks for that popawheelie i will try to make a ti spring

mike
Resident Pro
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Joined: Tue Mar 18, 2003 9:42 pm

by mike

nice, i'm going to give it a try....just ordered some ti spokes from madcow....

popawheelie
Posts: 1021
Joined: Thu Sep 26, 2002 3:42 pm
Location: in Colorado

by popawheelie

I weighed the Campy springs (5.3) and the Ti one (3.0). Almost half the weight.
Attachments
spring 5.3 reb 003 (2).jpg
Ti spring 3.0 reb 004 (2).jpg

rothshek
Posts: 150
Joined: Sat Nov 13, 2004 4:41 pm
Location: Hong Kong
Contact:

by rothshek

good job popawheelie
:P
why your ti-spring different color?? :?:

popawheelie
Posts: 1021
Joined: Thu Sep 26, 2002 3:42 pm
Location: in Colorado

by popawheelie

It's made out of a Ti spoke by Mauwri sp?. They are called tye-dyed spokes.

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Samu Ilonen
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Joined: Thu May 27, 2004 7:13 am
Location: Finland
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by Samu Ilonen

popawheelie wrote:I weighed the Campy springs (5.3) and the Ti one (3.0). Almost half the weight.


:D :D :D

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. :lol:

rothshek
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by rothshek

if u a not one of us .u a one of them :twisted:
so WW family :D

rothshek
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Joined: Sat Nov 13, 2004 4:41 pm
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by rothshek

hi popawheelie: why not try replace the rear mech with ti spring? :lol:

popawheelie
Posts: 1021
Joined: Thu Sep 26, 2002 3:42 pm
Location: in Colorado

by popawheelie

I have done a little work on the rear derraileur but not as extensive as the front. The Rear is maybe my next project.
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.

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twistyaction usa
Posts: 456
Joined: Sun Jan 09, 2005 1:09 am
Location: Portland, OR

by twistyaction usa

@popawheelie:
Have you tried less # of wraps on the f-der spring? It seems like it doesn't need too much travel, perhaps you could get away with less material and still get the desired effect. (2.0 only, though)

popawheelie
Posts: 1021
Joined: Thu Sep 26, 2002 3:42 pm
Location: in Colorado

by popawheelie

I think you could do less wraps. Good idea. I could try one. It would increase the strength of the spring though. But that might not be a bad thing.

by Weenie


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