Dura Ace 7900 STI makeover

Discuss light weight issues concerning road bikes & parts.
FastDad
Posts: 59
Joined: Thu Nov 05, 2015 2:48 pm

by FastDad

The next project has landed...I will try a makeover of the STIs for my road bike :D

I bought a pile of STI parts from a guy, who did took apart his lever, because of huge shifting problems

Image

I did sort the parts and puzzled some time...
Image

...what a surprise...he did not send all the parts :evil:
So I got in contact with him again and he send me all the missing parts. Not just 2 springs, some smaler pieces too.
Yesterday they did arrive finaly
Image

IT IS ALIVE!!! muuuhaha :twisted:
Image

The new project is born!
This winter I will try to change some internal parts and maybe the overall look of the 7900 STI




Please help me...I´m still looking for the left hand STI...very cheep...maybe one of the european members can help me out

FastDad
Posts: 59
Joined: Thu Nov 05, 2015 2:48 pm

by FastDad

One step further, just for the fun ;)

Image

by Weenie


TheKaiser
Posts: 511
Joined: Thu Sep 05, 2013 3:29 pm

by TheKaiser

You are an ambitious man, but after seeing your past projects I think you have the patience and attention to detail to pull this one off too!

FastDad
Posts: 59
Joined: Thu Nov 05, 2015 2:48 pm

by FastDad

Thanks
At least now I'm able to set a part a ST-7900 and rearange it to make it work ;)

jeffy
Posts: 1261
Joined: Sun Oct 05, 2014 11:51 pm

by jeffy

will be following this.

calvin
Posts: 121
Joined: Tue Nov 03, 2015 3:02 pm
Location: Europe

by calvin

Hope you will be able to fix it

FastDad
Posts: 59
Joined: Thu Nov 05, 2015 2:48 pm

by FastDad

To be honest...I made it already 3 times in the last couple of days

As it looks right now, I will try to put some original parts beside and make a different shifter sheme.
This project will need some time ;)

FastDad
Posts: 59
Joined: Thu Nov 05, 2015 2:48 pm

by FastDad

first idea:

At the silver hook on the right side you need to push to shift to a smaler gear
Image

Maybe I will fix a aloy piece with heavy glue at this hook. This piece will be located under the rubber hood finaly, so nobody can see it.
Image
Image
Image

I will safe these parts
Image

You can use it this way too:
Image

probably I will attach a carbon disc, to lower the presure to the rubber hood

FastDad
Posts: 59
Joined: Thu Nov 05, 2015 2:48 pm

by FastDad

of course the glue has to be strong...not heavy LoL

I think this was a good weekend for me
Today I removed the second metal lever from the shifting mechanism.
Image

After this I made some kind of prototyping with a piece of memory carbon I stored for a long time in one of my tubs
Image
Image
Image

Image
Image
Image


This way I will not just few gramma by swaping the metal lever
Image
...also I safe the big, heavy piece for the rotating mechanism at the head of the lever
Image
... and I can try for my own carbon lever now, which might be lighter too hopefully
Image


Any input for an individual brake lever shape?

pitbull
Posts: 59
Joined: Sun Mar 23, 2014 8:35 am

by pitbull

Awesome documentation! I do quite like the shimano lever shape. Possibly make it better in terms of Moment of inertia (Flächenträgheitsmoment ;) )

FastDad
Posts: 59
Joined: Thu Nov 05, 2015 2:48 pm

by FastDad

Thank you

Maybe you can make a skizze what came to your mind.
Here is my idea:

Image

User avatar
prendrefeu
Posts: 8610
Joined: Wed Oct 31, 2007 10:32 pm
Location: Los Feliz, Los Angeles, California
Contact:

by prendrefeu

Nice reduction of size! Are you planning on keeping the same "move entire lever to shift" style of Shimano, or use their mechanism perhaps with a second shift-specific lever like SRAM/Campagnolo ?
Exp001 || Other projects in the works.

FastDad
Posts: 59
Joined: Thu Nov 05, 2015 2:48 pm

by FastDad

prendrefeu wrote:Nice reduction of size! Are you planning on keeping the same "move entire lever to shift" style of Shimano, or use their mechanism perhaps with a second shift-specific lever like SRAM/Campagnolo ?


In fact mine will have 3 levers at the end...the knob for down shifteng, the little padle for up shifting and the brake lever.

Dynamo00
Posts: 33
Joined: Fri Sep 09, 2011 11:52 pm

by Dynamo00

I love your projects, can't wait to see more.

pitbull
Posts: 59
Joined: Sun Mar 23, 2014 8:35 am

by pitbull

Regarding your sketch i would make space for at least two fingers at the drop brake position (one straight line with the width of two fingers) and the same at the top. i would angle the bottom part a bit more to the front to prevent slipping but do it as you like. i meant to make it real thick at the top (most force there) and thinner at the bottom (looking from the side)

by Weenie


Post Reply
  • Similar Topics
    Replies
    Views
    Last post