Viewing 36 posts - 1 through 36 (of 36 total)
  • FAO doubters III (carbon brake mount & potential FLAME-AGEDDON content)
  • cynic-al
    Free Member

    As a follow up to my previous thread:

    http://www.singletrackworld.com/forum/topic/fao-doubters-ii-carbon-brake-mount-potential-flame-ageddon-content/page/2

    I’ve tarted the forks up a bit, don’t look too bad IMO.


    IMG_1396 by alan cole, on Flickr

    Looking reasonable do you not think?

    rOcKeTdOg
    Full Member

    No spoon?

    cynic-al
    Free Member

    😀

    Things have moved on from cutlery…but steel is still in use!

    iain1775
    Free Member

    Cynic Al’s fresh goods friday
    IS mounts are so last year, it’s a about post mounts now 😉

    Stoner
    Free Member

    looks good al.
    I missed the build. What did you use to bulk out the metal plate to get to the OD of the leg before carbon wrapping?

    cynic-al
    Free Member

    I went hi-tech – car body-filler 😎

    The proper stuff from Halfords like.

    Stoner
    Free Member

    makes sense, was thinking alraldite but would have cost a bit.

    Do you need to key the existing lacquer first?

    cynic-al
    Free Member

    I bonded the steel mounts directly to the fork first (after keying it), bolted the lower one to the fork-end, then added the filler, then put a few layers of carbon on top.

    I started off with araldite but then bought proper layering epoxy which is way cheaper but less viscous.

    Got a few more ideas for it 😎

    Stoner
    Free Member

    did you make a jig to get the IS mounts in the right place relative to the drop outs?

    bigyinn
    Free Member

    That actually looks quite good. Good effort sir!

    cynic-al
    Free Member

    Oooh another compliment, thanks 😀

    Stoner I just tightened a BB7 caliper onto a disc and did it that way. I used a rear adaptor so I could keep the mount smaller. Not like I’ll ever sell the fork on!

    IanMunro
    Free Member

    Looking good.
    When are we going to see the 30mph to zero stoppie on youtube?

    wwaswas
    Full Member

    *disappointed that no cutlery was harmed in the making of this disk mount*

    Looks quite neat.

    bristolbiker
    Free Member

    Chapeau Al – that’s pretty neat for a DIY job. I never said you couldn’t do it 😉 A couple of thoughts:

    – One leg is now way stiffer than the other – do you notice this in the handling?
    – Why put the mounts on the front (is it just to keep access to the mudguard eye?)? All the braking forces are putting your handywork into tension
    – You’ve got a lovely stress concentration at the lower edge of the upper eye, where the fork section changes from very thick to very thin as it tapers toward the dropout. The caliper brace will add stiffness across the gap, but I’d keep an eye on this area as being the first place to give you problems (all else being equal).

    ski
    Free Member

    Will it blend?

    😉

    Only joking, that looks a neat botch to me.

    cynic-al
    Free Member

    IanMunro – Member
    Looking good.
    When are we going to see the 30mph to zero stoppie on youtube?

    I’ll do what I can (with a static camera) over the weekend.

    bristolbiker – Member
    Chapeau Al – that’s pretty neat for a DIY job. I never said you couldn’t do it A couple of thoughts:

    – One leg is now way stiffer than the other – do you notice this in the handling?

    Not at all – I am not convinced it is actually stiffer

    – Why put the mounts on the front (is it just to keep access to the mudguard eye?)? All the braking forces are putting your handywork into tension

    1. Mostly to avoid the mounts compressing the carbon and possibly cracking it.
    2. also to stop the axle lifting out of the fork-end….
    3. and to make mounting mudguards easier.

    – You’ve got a lovely stress concentration at the lower edge of the upper eye, where the fork section changes from very thick to very thin as it tapers toward the dropout. The caliper brace will add stiffness across the gap, but I’d keep an eye on this area as being the first place to give you problems (all else being equal).

    Possibly – but hopefully the carbon wrap along the length of the upper mount is spreading the stress – the mount is actually pulling it down the fork leg as well as away from it.

    bristolbiker
    Free Member

    Not at all – I am not convinced it is actually stiffer

    It is – there is no way you could NOT increase the second moment of area of the section by doing what you’ve done – the question, more accurately, is by how much is one leg stiffer than the other, or (back to my original Q) is it enough to notice in the real world?

    Possibly – but hopefully the carbon wrap along the length of the upper mount is spreading the stress – the mount is actually pulling it down the fork leg as well as away from it.

    The corner is so tight on the inside edge of the upper bracket, you’re stress concentration on the surface is effecitvely geometric, rather than material driven. Just keep an eye on it, that’s all I was saying.

    cynic-al
    Free Member

    bristolbiker – Member
    It is – there is no way you could NOT increase the second moment of area of the section by doing what you’ve done – the question, more accurately, is by how much is one leg stiffer than the other, or (back to my original Q) is it enough to notice in the real world?

    Maybees….as you say though it’s all relative – the leg itself is already pretty stiff to start with. I certainly didn’t notice any difference. It’s arguable that the added stiffness counter-acts the neding force created in that leg when braking – but I’d say that’s BS also!

    The corner is so tight on the inside edge of the upper bracket, you’re stress concentration on the surface is effecitvely geometric, rather than material driven. Just keep an eye on it, that’s all I was saying.

    Ah – you mean the point just above the brake bolt-hole?

    bristolbiker
    Free Member

    There and (bare with me on this….)….. in your photo, if you drew a line through the centre fo the dropuout on THE OTHER fork blade, through the centre of the mudguard eye on THE OTHER fork leg, then put an arros head on that line, it would be pointing to the corner I was talking about.

    I don’t want to dragged into these details really – you’ve done a cracking ‘man-in-a-shed’ job, so lets wallow in this success and see how it goes, rather than decending into the usual STW bun fight!

    cynic-al
    Free Member

    Ah OK gotcha – the steel plate ends there, I’m no concerned but will keep an eye on it ta.

    I was so hoping for a bun-fight 🙁

    Elfinsafety
    Free Member

    Poor Al. He tried so hard, yet all people did was be nasty and cruel. 🙁

    We need people like this; trying out new ideas, risking their own lives so’s we can learn to do stuff ourselves.

    Lots of pioneers died so that we can now fly in almost complete safety to wonderful places around the World.

    Please try not to get mash up an bash up an ting though Al.

    anotherdeadhero
    Free Member

    Looks tasty al. Nice work.

    Steve-Austin
    Free Member

    Poor effort, its on the wrong side. 1/10

    rootes1
    Full Member

    roadrat forks have the mount on the wrong side as well..

    cynic-al
    Free Member

    OK here’s a video, didn’t manage 30mph but probbers 20, brake not the strongest for whatever reason, but I think you’ll agree this is pretty impressive:

    [video]http://www.youtube.com/watch?v=kHMJd0LF39g[/video]

    Junkyard
    Free Member

    no endo followed by a trackstand ******* amateur
    No idea as to safety but it looks cracking 😀
    IGMC

    hilldodger
    Free Member

    bonus points for sandals 🙂

    cynic-al
    Free Member

    Sandals and shorts for as long as possible – I am a celt!

    Houns
    Full Member

    cynic-al – Member

    Sandals and shorts for as long as possible – I am a fluffy bunny!

    Oops wrong place

    singlespeedstu
    Full Member

    I think you’ll agree this is pretty impressive:

    Yep.
    The way you owned that kurb at the end of the video showed it who was in charge.

    cynic-al
    Free Member

    Both missing the sarcastic joke (I rarely make them though so they must be tough to spot 🙄 ) and point scoring in one post?

    singlespeedstu
    Full Member

    sarcastic joke?

    I’m being dead serious that kurb was propper owned.

    It’ll be a long time before it dares to get between you and the footpath again.

    cynic-al
    Free Member

    Ah well some of us don’t need to post up stuff to big ourselves up and don’t take ourselves too seriously 🙄

    Anyway if you don’t like this crap then I know it’s personal:


    IMG_1399 by alan cole, on Flickr


    IMG_1401 by alan cole, on Flickr

    singlespeedstu
    Full Member

    Upside down bike next to a washing line?

    You could have at least hung it from the line.

    *Walks away dissapointed*

    warton
    Free Member

    that doesn’t look at all shabby. Good Carbon Fibre Skills!

    Houns
    Full Member

    Nice bike, shame about the tragic end it will come to 🙁

Viewing 36 posts - 1 through 36 (of 36 total)

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