Introduction: Carbon Fiber Bicycle Fork

Picture of Carbon Fiber Bicycle Fork

How to make a carbon fiber bicycle fork

Step 1: Materials

Picture of Materials
  • carbon fiber mat
  • epoxy
  • 404 High density adhesive filler
  • foam
  • MDF
  • vacuum bag materials
  • Trash bags

Step 2: Tools

Picture of Tools

  • CNC router
  • vacuum pump
  • drill
  • ban saw
  • drill press
  • drill bits
  • tap and die set
  • dremel
  • drill bits

Step 3: Choose Your Setup

Before you start to design your fork you will need to get your hub, rim, decide on what type of brake you want, and the size of your head tube. The fork I made is going to be for a front wheel drive bicycle so I went with a NuVinci hub, 20" wheel, disk brake, and 1 1/8 headset.

Step 4: ​Design and Cut Out the Wheel Mounts

Picture of ​Design and Cut Out the Wheel Mounts

the wheel mounts need to be strong enough to hold the wheel to the fork during high speed braking. The mounts I will use three bolts for mounting. The left mount has a disk brake attachment and the right mount has an attachment for a chain tensioner.

Step 5: Fork Jig

Picture of Fork Jig

When assembling the fork you will need the help of a jig to get the wheel mounts in the correct places. When building the jig you will need MDF threaded rod, nuts and washers. Place a fork on a flat table with the steering tube level with the table. measure the distance form the steering tube to the wheel mounts, the distance from the table to the wheel mounts and the diameter of the steering tube. In drawing software plot all the points to establish the mounting locations. The software I used is Autodesk Inventor. Once the three points are in the software then you can design your jig around them.

Step 6: Design the Fork

Picture of Design the Fork

using the same points as the jig design the fork.

Step 7: Design the Female Molds

Picture of Design the Female Molds

You will need a top and bottom female mold that splits in the center of your fork.

Step 8: Cut Out the Molds on the CNC

Picture of Cut Out the Molds on the CNC

Step 9: Epoxy Sand and Wax the Molds

Picture of Epoxy Sand and Wax the Molds

Step 10: Vacuum Bag the Carbon Fiber

Picture of Vacuum Bag the Carbon Fiber

  • lay down a trash bag
  • place mastic tape around your mold.
  • cut out the vacuum bag materials.
  • wet out your mold with epoxy
  • wet out your carbon fiber with epoxy
  • lay in two layers of wet carbon fiber
  • vacuum bag the mold overnight

Step 11: Remove the Part From the Mold and Trim the Edges

Picture of Remove the Part From the Mold and Trim the Edges
  • to trim the edges use a band saw and sand paper.

Step 12: Fill With Thickened Epoxy

Picture of Fill With Thickened Epoxy

  • I wanted to make sure this part was very strong so I filled most of the fork with thickened epoxy.
  • now is the time to glue in the steering tube to one half of the fork
  • wax another pipe and glue it to the other half
  • once dry pop off the waxed pipe and it will leave space for when you glue the two sides together.
  • once dry sand the thickened epoxy

Step 13: Glue Both Sides Together

Picture of Glue Both Sides Together

  • use electrical tape to hold both sides together while they dry.
  • after your fork is dry sand it smooth.

Step 14: Drill Holes for Your Wheel Mounts

Picture of Drill Holes for Your Wheel Mounts

  • pick out the bolts you want to use find the tap and drill bit that goes with it
  • place the fork in your jig
  • clamp your wheel mounts to the outside of the fork
  • drill the bolt holes
  • don't tap the holes yet

Step 15: Wrap the Perimeter in Carbon Fiber

Picture of Wrap the Perimeter in Carbon Fiber

  • wet out the carbon fiber
  • wrap the perimeter with a strip of carbon fiber
  • vacuum bag the fork
  • once dry use a dremel and open the holes on the inside of the fork don't drill all the way through
  • tap the holes

Step 16: Make It Shiny

Picture of Make It Shiny

  • place electrical tape over the holes
  • hang the fork and brush on epoxy to get a nice shine

Step 17:

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assemble your fork and bolt it on to your wheel.

Comments

fullclip765 (author)2016-04-24

do you race in nbl or aba

jw how hold up on track like bombshells suck ive seen too many bust the answer are ok if you got 4-5 hundred bucks to throw away

aideym (author)2015-04-27

Very nicely done indeed. Would love to see the rest of the bike build as I'm just starting a MBB bike myself

Charlie9 (author)2015-04-15

With all of that epoxy did it end up saving much weight when it was done?

nathan.stoddard.18 (author)2015-04-11

Awesome, carbon-fiber vacuum forming is just too cool.

SCHLEPIC (author)2015-04-09

Have you tested the fork yet? Please update us when you do. My fingers are crossed for you!

Hucul19 (author)2015-04-08

The drawing software I used to make the forks and molds was Autodesk Inventor

remington700links (author)2015-04-07

Great project
Been thinking about making a project in carbon.
What glue did you use to glue the folks,guessing it was epoxy glue ?

I used west system 105 epoxy resin with 205 slow hardner mixed with 404 high density filler

diy_bloke (author)2015-04-07

great. bot that i see myself do this any time soon but interesting nevertheless

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