My Carbon Frame Flop

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Introduction: My Carbon Frame Flop

There are great success stories on this site, It's the first place I go to get started on a project for some tips and interesting ideas. I thought why not have a failure story on here too......

A few years ago I decided to make my own Carbon bicycle frame using things around the house,

This is how it went.

Step 1: Building the Frame Jig From Old Pallets

I was very keen I collected some old pallets (hey , I can enter this into the pallet contest :) ) cut them up and nailed up a frame.

Step 2: Frame Parts

I chopped up an old aluminium frame for the important bits ( head tube,BB,stays, etc.) and positioned them on hard foam pieces, I used string to set angles and lines.

Everything seemed fine.

Step 3: Building the Foam Frame

I used foam to build the frame into the pieces I had already set in the jig.

Step 4: Strong the Joints

I started to lay up the carbon fiber cloth and paint on the resin, Then wrapped it with insulation tape I drilled holes into.

This squeezed out the excess resin, Don't forget to wrap sticky side up.

Step 5: Resin

Here you can see how the resin is pushed out by the tightly bound insulation tape.

When you remove the tape the excess resin comes with it leaving only pin points on the carbon fiber, these are easily sanded off afterwards.

Step 6: Foam Filler

I used foam filler to shape the pieces where the tubes came together,

What I didn't notice is that the head tube had moved and was now at less of an angle

Step 7: Layers of Carbon

Every night I would go remove tape and add another layer, I spent endless nights in the garage until it was done.

I put all the parts on and took it out for a test ride, because the head tube moved it changed the handling completely. If you turn the handle bars too far it will buck you over like a rodeo clown.

I removed all the parts and it now hangs in my garage as a very expensive reminder after doing only 20 m on the road.

The point is that many people are apprehensive to try things,to make things, you will fail BUT there will be far more times that your friends come over and say "Wow, that's awesome!"

To which you proudly reply " Thanks, I made it..."

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    32 Comments

    How much, and in which direction did the head tube move? What was it that caused it to move? What could you have done to prevent it?

    1 reply

    this is the point! try again again again!

    Amazing what 20~30 degrees make, isn't it?

    1 reply

    Even fairly competent cyclists will notice like a one degree difference. just saying 30° is a massive amount.

    Want a cheaper and EASIER fix? Fit a smaller rear wheel or a larger front wheel to get the head angle closer to normal.

    You want the cheap and easy fix?

    Go to the local Charity shop or junkyard and find an old Diamond-frame for next to nothing. Strip off any decent parts for another project. Make sure that the head tube is okay and still properly angled, and that the steel tubes will fit inside the tubes of your carbon frame...slice off the head tube but leave about two inches of tube hanging off the head tube. Remove paint.

    Slice off your Carbon frame's head tube and about one inch of CF tubing in both directions of the diamond. Once the diamond is open, slide the salvaged head tube right in its place. Return to jig, check angles and alignment one final time and epoxy in place.

    Once the epoxy has dried, rough up the CF tubing about one inch in, layer more CF around the replacement head tube and into your tubes for further reinforcement. The angles should now be perfect at the cost of a few extra ounces weight-you could try a salvaged aluminum headset for this instead, but personally I have trouble finding those...

    maybe try to make custom fork with angle correction or maybe try to find one with bigger [forward/passing[?]? :P

    Would it have been easier to control the angles, etc. by building it in 2 or 3 pieces then putting them together? Regardless, you can't learn something unless you try it. Keep it up!

    Wow ! Take a firm hold of all these encouraging coments ! Here's mine:

    "It's not a failure, it's an experimental engineering prototype undergoing technological improvement and developmental upgrading."

    (Make these words into a label and hang them on the frame.)

    (And memorise them for the next time you fall off in public !-)

    I had no clue that's how carbon fiber frames are made, I think your a genius myself. Love to get a hold of some old frames now and build some recumbent bikes. Thanks for sharing, and yes my money is on your already figured out how to fix the frame.

    This is specific to game design but it rings true in all design endeavors.

    Thank you for sharing your failure. Now go build something.

    1 reply

    http://www.lightsandlights.com/thomas-edison-light...

    Here are two Thomas Edison light bulb quotes: one on trying 10,000 times
    “I have not failed. I’ve just found 10,000 ways that won’t work.” and
    another on our greatest weakness “Our greatest weakness lies in giving
    up. The most certain way to succeed is always to try just one more
    time.”

    Every time I build anything I'm constantly trying to improve on the idea. This, of course, results in many errors, do-overs as well as wasted time, money and materials. But just like in golf or even marriage, I learn more from my errors and love the game for the individual accomplishments even if actually attributed to just trial and error or even luck.

    Thanks for the great instructable. I like the jig!. "Trail" = castor dimension. Trail = the distance the front wheel contact point is behind the place where the steering axis hits the ground. It looks like the head angle "steepened" to become more vertical and reducing or reversing the trail. A possible fix is a smaller front wheel and a longer fork to keep the bike level with smaller wheel. and the fork set in backwards so the offset produces (instead of consumes) trail. try for about 3/4" to 1" trail. I think my Mountain Bike Scooter ibis explains it somewhat.

    1 reply

    if instead, the head angle is too shallow (wheel sticks out too far) the normal fork and wheel produce too much trail and the fork needs more offset (aka rake or bend). bending the blades so the wheel is even further in front moves its road contact point up closer to the steering axis and consumes excess trail.

    Put tiny wheel on back, huge one on front, correct angle some and it'll look crazy...

    1 reply

    and don't forget to change the gearing to accommodate the small rear wheel.

    just a thought... maybe already put in here, I didn't read all the comments... but how about finding a new front fork with a little more trail or buy a lightweight steel fork like Tange 2 or something... an aero fork, then bend fork legs out abut 1" forward... Maybe have to go a little more... but with that trail it may help bike center itself better and also recent face plant...lol Just saying... don't give up until its time to give up!

    You tried and we all learned - that still makes it a valuable Instructable.

    He's a Quote from 1910 by Teddy Roosevelt - you are the man in the arena:

    It is not the critic who counts; not the man who points out how the strong man stumbles, or where the doer of deeds could have done them better. The credit belongs to the man who is actually in the arena, whose face is marred by dust and sweat and blood; who strives valiantly; who errs, who comes short again and again, because there is no effort without error and shortcoming; but who does actually strive to do the deeds; who knows great enthusiasms, the great devotions; who spends himself in a worthy cause; who at the best knows in the end the triumph of high achievement, and who at the worst, if he fails, at least fails while daring greatly, so that his place shall never be with those cold and timid souls who neither know victory nor defeat.

    Well done!

    failure is the prelude to success. i doubt anyone invents anything that works right on the first go.