Carbon Fiber shifter clamps for Sram

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nvroadie
Posts: 190
Joined: Tue Mar 31, 2015 11:11 pm

by nvroadie

Hello Weight Weenies,
I want to create a thread to showcase my latest project: to make carbon fiber shifter clamps for Sram Red Yaw shifters. There are carbon clamps made for shifters by companies such as tune, but these don't fit newer Sram shifters. Many may call this project "stupid" or "dangerous" (like my mother), but with the proper manufacturing and testing, these can be made completely safe. Before I start in on the design and manufacturing process, I want to discuss the facilities I am working in. My parents have allowed me the use of the back of their pole building and my dad's wood working equipment wich I have adapted for use with composites and metal. I have a jigsaw, dremel, dremel jig, a drill press and a and a vacuum sealer. I also want to point out that these machines are hooked to a dust collection system while in use. I also have a 3M mask and full face shield. Also, please don't try this at home. :D DISCLAIMER: I am NOT responsible for any injury that may occur to one that attempts to copy the following.

Design

To fit the shifter and bar, the clamp must be roughly the same size as the stock steel clamp. To get this shape I traced the inside of the stock clamp onto foam, and cut it out with the jigsaw. This piece of foam is essentially the mold.

Building

I started with 3 pieces of carbon, each the same width of the piece of foam, and long enough to wrap around it twice. I added resin to these and wrapped them onto the foam. I don't have many pictures, as I had resin on my gloves and don;t want my phone covered in resin. I then stuck the pieces in bags for the vacuum sealer and sealed them up. After 7 hours I opened them up and used a drill bit to get the foam out of the center. Considering that I am terrible with the jigsaw, I had to heat the piece up with a heat gun and mold it to achieve the proper shape.

Hardware

For version 1, I used the stock hardware. I began work on version 2 today, wich used a piece of aluminum molded into the front as a nut. I have to tap and drill this. I have some aluminum bolts on order from Toronto Cycles, wich will complete version 2.

Future Enhancements

Going into this, I thought that I would use version 1 and call it good, but I have become obsessed. I have already begun to think of ideas for version 3 and beyond. I have enlisted the help of a friend for testing and building. I have no plans to sell these, especially not the ones I am making now. The first version that will even go on bike will be version 3. Versions 1&2 have held up to "lab" testing (clamped to an old pair of bars in the vise), but the open road is a frightening thought. I plan
to update this thread with my current findings, but I may divert some of my time to bottle cage building.

nvroadie

Marin
Posts: 4035
Joined: Wed Jan 22, 2014 11:48 am
Location: Vienna Austria

by Marin

Cool project!

Thread need pics.

by Weenie


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nvroadie
Posts: 190
Joined: Tue Mar 31, 2015 11:11 pm

by nvroadie

I will definitely add pics tonight!

trimenc
Posts: 111
Joined: Mon Aug 01, 2016 2:39 am
Location: North Carolina

by trimenc

I am looking forward to seeing pictures. It does seem easy enough, in theory...

nvroadie
Posts: 190
Joined: Tue Mar 31, 2015 11:11 pm

by nvroadie

Version 2 will be out of the mold tonight, and I will post pictures of both 1 & 2 with the corresponding hardware. And no, it isn't too difficult, you just need the right equipment.

NiFTY
Posts: 1493
Joined: Sat May 26, 2012 11:26 pm

by NiFTY

Photos? I have some tune/btp ones that i have used for thousands of k's without issue.
Evo 4.9kg SL3 6.64kg Slice RS 8.89kg viewtopic.php?f=10&t=110579" onclick="window.open(this.href);return false;" onclick="window.open(this.href);return false;

nvroadie
Posts: 190
Joined: Tue Mar 31, 2015 11:11 pm

by nvroadie

Since everyone wants pictures, here are some bad ones of version 1:

ImageWith stock hardware, saves 7.9g per side!

ImageThis is an aluminum nut that I made to work with a separate bolt on version 1. In version 2, the aluminum is molded in. This will allow me to make the clamps narrower to work with 2013 shifters.

nvroadie

nvroadie
Posts: 190
Joined: Tue Mar 31, 2015 11:11 pm

by nvroadie

I tested version 2 yesterday, and found that it couldn't even hold up the minimum torque before it cracked. Even though I used a grinding wheel on the aluminum plate before I molded it in, in hopes creating a better bond, when drilled and tapped the aluminum broke loose and damaged the carbon.

Image

Here is the damaged version 2

Image

Here is the piece that I cut individual clamps from. As you can see the carbon didn't fill around the aluminum very well, leaving a void, which could also be a weakness.

Version 3 will include the same basic carbon structure as version 1, but with a nut JB welded or epoxied to the inside. This should help with the strength needed to make the clamp narrow enough for Yaw shifters.

Image

This is the basic carbon part for version 3, still on the foam mold. I should have some updates on Friday after I have completed all my semester exams.

nvroadie

nvroadie
Posts: 190
Joined: Tue Mar 31, 2015 11:11 pm

by nvroadie

I completed version 3, but haven't tested it because my bolts haven't arrived. The aluminum nut is JB Welded to the clamp.

Image

nvroadie

Mep
Posts: 516
Joined: Fri May 28, 2004 4:11 pm

by Mep

Very cool! Look forward to your testing results.

by Weenie


Visit starbike.com Online Retailer for HighEnd cycling components
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