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Dura Ace 7900 STI makeover

Posted: Thu Nov 12, 2015 4:57 am
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

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I did sort the parts and puzzled some time...
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...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
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IT IS ALIVE!!! muuuhaha :twisted:
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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

Dura Ace 7900 STI makeover

Posted: Thu Nov 12, 2015 4:57 am
by Weenie

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Re: Dura Ace 7900 STI makeover

Posted: Fri Nov 13, 2015 5:30 am
by FastDad
One step further, just for the fun ;)

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Re: Dura Ace 7900 STI makeover

Posted: Fri Nov 13, 2015 6:35 am
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!

Re: Dura Ace 7900 STI makeover

Posted: Fri Nov 13, 2015 7:04 am
by FastDad
Thanks
At least now I'm able to set a part a ST-7900 and rearange it to make it work ;)

Re: Dura Ace 7900 STI makeover

Posted: Fri Nov 13, 2015 2:30 pm
by jeffy
will be following this.

Re: Dura Ace 7900 STI makeover

Posted: Fri Nov 13, 2015 2:44 pm
by calvin
Hope you will be able to fix it

Re: Dura Ace 7900 STI makeover

Posted: Sat Nov 14, 2015 4:01 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 ;)

Re: Dura Ace 7900 STI makeover

Posted: Sat Nov 14, 2015 11:08 pm
by FastDad
first idea:

At the silver hook on the right side you need to push to shift to a smaler gear
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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.
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I will safe these parts
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You can use it this way too:
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probably I will attach a carbon disc, to lower the presure to the rubber hood

Re: Dura Ace 7900 STI makeover

Posted: Sun Nov 15, 2015 7:15 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.
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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
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This way I will not just few gramma by swaping the metal lever
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...also I safe the big, heavy piece for the rotating mechanism at the head of the lever
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... and I can try for my own carbon lever now, which might be lighter too hopefully
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Any input for an individual brake lever shape?

Re: Dura Ace 7900 STI makeover

Posted: Sun Nov 15, 2015 8:49 pm
by pitbull
Awesome documentation! I do quite like the shimano lever shape. Possibly make it better in terms of Moment of inertia (Flächenträgheitsmoment ;) )

Re: Dura Ace 7900 STI makeover

Posted: Sun Nov 15, 2015 9:42 pm
by FastDad
Thank you

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

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Re: Dura Ace 7900 STI makeover

Posted: Sun Nov 15, 2015 9:59 pm
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 ?

Re: Dura Ace 7900 STI makeover

Posted: Mon Nov 16, 2015 5:04 am
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.

Re: Dura Ace 7900 STI makeover

Posted: Tue Nov 17, 2015 1:56 am
by Dynamo00
I love your projects, can't wait to see more.

Re: Dura Ace 7900 STI makeover

Posted: Wed Nov 18, 2015 7:26 pm
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)

Re: Dura Ace 7900 STI makeover

Posted: Wed Nov 18, 2015 7:26 pm
by Weenie

Visit starbike.com Online Retailer for HighEnd cycling components
Great Prices ✓    Broad Selection ✓    Worldwide Delivery ✓

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