Drilling Carbon Track Fork

poria
poria Posts: 6
edited January 2011 in Workshop
I've got a carbon track fork which isn't drilled for brakes. I took it to two places, one said they wouldn't drill it, the other said they would drill it reluctantly, but would probably ruin it and will not accept responsibility. Can anyone tell if it's possible and if so where, through these photos? Thanks!
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Comments

  • meanredspider
    meanredspider Posts: 12,337
    I don't blame them for saying they wouldn't do it. Where did you get the fork? Holes in any material are real stress-concentration points and can lead to cracking/tearing (it's why balloons pop). I'd ask the manufacturer to do it. I don't think carbon-fibre is hard to drill - I'm sure a Black & Decker and an HSS bit would put a hole in it - I'd just feel nervous about how much strength I'd removed...

    EDIT - have you tried scratching the surface at the points it looks like the holes should be? Are you sure the hole isn't already "moulded in"? That threaded rod looks like it is doing something...
    ROAD < Scott Foil HMX Di2, Volagi Liscio Di2, Jamis Renegade Elite Di2, Cube Reaction Race > ROUGH
  • poria
    poria Posts: 6
    I don't blame them for saying they wouldn't do it. Where did you get the fork? Holes in any material are real stress-concentration points and can lead to cracking/tearing (it's why balloons pop). I'd ask the manufacturer to do it. I don't think carbon-fibre is hard to drill - I'm sure a Black & Decker and an HSS bit would put a hole in it - I'd just feel nervous about how much strength I'd removed...

    EDIT - have you tried scratching the surface at the points it looks like the holes should be? Are you sure the hole isn't already "moulded in"? That threaded rod looks like it is doing something...

    I dont know what the rod is there for..there's quite a deep, narrow hole on one side, the other is solid
  • meanredspider
    meanredspider Posts: 12,337
    The rod looks like the same diameter as brake mounting stud - in about the correct position
    ROAD < Scott Foil HMX Di2, Volagi Liscio Di2, Jamis Renegade Elite Di2, Cube Reaction Race > ROUGH
  • unixnerd
    unixnerd Posts: 2,864
    Is it my imagination or does one side of that look like the top of a flat head screw? Are you sure there isn't a screw in there and you just need to undo it?
    http://www.strathspey.co.uk - Quality Binoculars at a Sensible Price.
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  • poria
    poria Posts: 6
    the diameter of the hole is 4mm
    i think i need to drill a hole slightly wider
  • jonmack
    jonmack Posts: 522
    Looks like the hole has been pre-drilled then filled with a blank, from what I've read that's pretty common on track forks, try scraping the paint away from the place where the hole should clearly be.
  • Monty Dog
    Monty Dog Posts: 20,614
    The screw was probably used to hold the crown and steerer together during assembly - it's well-bonded-in by the look of it. What material is the fork crown? If alloy I'd give it a go, but would be more wary if it was carbon. As you're probably going to have to drill-out a harder steel screw surrounded by a softer material, you need to do this with the fork firmly clamped in a drill-press. Freehand drilling will probably cause the drill to wander and damage the fork. I'd certainly remove the paint at both ends to understand what lies underneath e.g. what materials are used.
    Make mine an Italian, with Campagnolo on the side..
  • moonshine
    moonshine Posts: 1,021
    I would not drill carbon willy nilly.
    Carbon is not a fibrous form of aluminium and if you drill the carbon threads, you effectively break them and significantly reduce the structural strength.

    In sailing, plenty of carbon masts / spinnaker poles have failed due to people not understanding the material properties of carbon and drilling into it, screwing through it or riviting things without understanding that it behaves very differently to aluminum when drilled and structural integrity can be significantly comprimised

    If you can get the threaded rod out and reuse the holes, then you would be on a winner... otherwise i'd be inclined to get a new road specific fork.

    edit.... but if the area around the bolt is alloy, with the carbon legs bonsed below it, then drilling should be fine - agree dig around the bolt hole and see what materials are involved...
  • fuelex
    fuelex Posts: 165
    A friend of mine has just drilled out the carbon fork on a Fuji track pro, looks similar to yours.
    He's a bike mechanic but still wasn't too keen on doing it!
    The threaded bolt/screw inside had no head on it so couldn't be unscrewed.
    Saying that, he managed it and put a sleeve in and now has a front caliper on.
    It hasn't broken........yet!
  • poria
    poria Posts: 6
    fuelex wrote:
    A friend of mine has just drilled out the carbon fork on a Fuji track pro, looks similar to yours.
    He's a bike mechanic but still wasn't too keen on doing it!
    The threaded bolt/screw inside had no head on it so couldn't be unscrewed.
    Saying that, he managed it and put a sleeve in and now has a front caliper on.
    It hasn't broken........yet!

    This fork is actually from a Fuji Track 1.0...what did your friend do about the screw? How did he remove it? Because it's directly in the way of where the caliper needs to go
  • fuelex
    fuelex Posts: 165
    poria wrote:
    fuelex wrote:
    A friend of mine has just drilled out the carbon fork on a Fuji track pro, looks similar to yours.
    He's a bike mechanic but still wasn't too keen on doing it!
    The threaded bolt/screw inside had no head on it so couldn't be unscrewed.
    Saying that, he managed it and put a sleeve in and now has a front caliper on.
    It hasn't broken........yet!

    This fork is actually from a Fuji Track 1.0...what did your friend do about the screw? How did he remove it? Because it's directly in the way of where the caliper needs to go

    He had to drill it out....very carefully!
    The steel screw is a lot harder than the surrounding material.
  • poria
    poria Posts: 6
    fuelex wrote:
    poria wrote:
    fuelex wrote:
    A friend of mine has just drilled out the carbon fork on a Fuji track pro, looks similar to yours.
    He's a bike mechanic but still wasn't too keen on doing it!
    The threaded bolt/screw inside had no head on it so couldn't be unscrewed.
    Saying that, he managed it and put a sleeve in and now has a front caliper on.
    It hasn't broken........yet!

    This fork is actually from a Fuji Track 1.0...what did your friend do about the screw? How did he remove it? Because it's directly in the way of where the caliper needs to go

    He had to drill it out....very carefully!
    The steel screw is a lot harder than the surrounding material.

    Ok, thanks thats really helpful. I actually gave it to a mechanic today, I'll call him tomorrow and tell him about drilling it out
  • fuelex
    fuelex Posts: 165
    poria wrote:
    fuelex wrote:
    poria wrote:
    fuelex wrote:
    A friend of mine has just drilled out the carbon fork on a Fuji track pro, looks similar to yours.
    He's a bike mechanic but still wasn't too keen on doing it!
    The threaded bolt/screw inside had no head on it so couldn't be unscrewed.
    Saying that, he managed it and put a sleeve in and now has a front caliper on.
    It hasn't broken........yet!

    This fork is actually from a Fuji Track 1.0...what did your friend do about the screw? How did he remove it? Because it's directly in the way of where the caliper needs to go

    He had to drill it out....very carefully!
    The steel screw is a lot harder than the surrounding material.

    Ok, thanks thats really helpful. I actually gave it to a mechanic today, I'll call him tomorrow and tell him about drilling it out

    Good luck, its got to be better than no front brake!
    Not sure what wheels you've got on, but he was a bit annoyed that all the paint was stripping of as they weren't machined as a braking surface.
    They also didn't stop too well in the wet apparently.
  • edhornby
    edhornby Posts: 1,780
    why not just get a budget fork with a hole in it?? surely gotta be less hassle, and I'd trust it more than a fork with a hole that 2 shops wouldn't drill...
    "I get paid to make other people suffer on my wheel, how good is that"
    --Jens Voight
  • moonshine
    moonshine Posts: 1,021
    fuelex wrote:
    The threaded bolt/screw inside had no head on it so couldn't be unscrewed.

    if it is threaded with no head, use an easyout? http://www.machinemart.co.uk/shop/product/details/cht526-12pce-drill-screw-extractor-s/path/screw-bolt-and-stud-extractors