Instructables
Picture of 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.

 
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Step 1: Building the frame jig from old pallets

Picture of Building the frame jig from old pallets
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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

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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

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

Step 4: Strong the joints

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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

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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

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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

neaton15 months ago

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

Even fairly competent cyclists will notice like a one degree difference. just saying 30° is a massive amount.
lmvlobos5 months ago

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

order995 months ago

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...

Boobr5 months ago

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

caruncles5 months ago

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!

Naugas5 months ago

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?

ElectroFrank5 months ago

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 !-)

sbushard5 months ago

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.

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.”

bobjacksonjr5 months ago

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.

Woodenbikes5 months ago

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.

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.

ac-dc5 months ago

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

ac-dc ac-dc5 months ago

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

dparham15 months ago

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!

Photomancer5 months ago

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!

fixfireleo5 months ago

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

Kevanf15 months ago

Well done. You tried even though it turned out not to work... this time. Hopefully you'll go back, redo your steps but this time make sure that headstock is rock solid :) I'm willing to bet that you have a deep down itch to do this again and get it right this time :)

Tooraj5 months ago

Just curious, did you weigh the before and after? I mean how did the sacrificial bike weighed compared to the new carbon bike?

tonygagey5 months ago
recut the head and re align, fix in place with splines and re epoxy in place , check carefully using a pre cut pattern that you have the right amount of rake , yon could still save the bike!
Been there, done that too, but thankfully, mostly with food and crocheting projects. I am proud of you for trying! Thanks for sharing!
neo716656 months ago
Love it when people post not only success but failures.

I'd suggest some extremely lightweight aluminum tube that will fit in the stubs. Pop rivet it in place to hold the angles. You could even drill holes in it to lighten the weight more. That should hold everything in place better while wrapping the CF. Short of building a steel jig that clamps the parts better that's the only thing my simple mind can come up with.
Tom Hargrave6 months ago

I would not call this a failure, I would call this one step towards success. The next steps would be to replace the parts you cut off an old frame with your own design made of welded up tube and design a better layout fixture. You are very close to a frame that can be manufactured & sold to others!

You did more than I could've. The reason the wheel would move like that is because the neck angle wasn't giving you the correct trail. Giving you wheel "flop". If you ever attempt this again I would consider using vacuum bags to create the frame. It removes more resin, but with less effort and keeps just as strong!
pantalone6 months ago

Thanks for posting about your experience. We often learn more from our mistakes than our successes. I'm impressed that you were able to do this much.

manu19756 months ago

the first thing for learnig how to get up is to fall down! so you are in a good way! go on!!

bricobart6 months ago

Every succes is paved on a road of mistakes, that's called experience... You did a long way, next time will be bulls eye! Keep going!

craftclarity6 months ago

Wow, big ups for going for it! You should enter it in the pallet contest!!

rickharris6 months ago

every failure is just 1 step towards success. It's a problem when making prototypes - you often get it wrong.

In this case why not cut the cross bar and down tube reset the angle and tape it up if the rest is fundementally OK.