My latest hare brained scheme

Home Forum Bike Forum My latest hare brained scheme

Viewing 40 posts - 1 through 40 (of 52 total)
  • My latest hare brained scheme
  • Premier Icon 2unfit2ride
    Subscriber

    It’s your face, crack on 😉

    Forks, you say?

    Sorry, I haven’t got the tine to think of anything witty to say.

    Premier Icon geoffj
    Subscriber

    re glue the dropouts/brake mount on

    😯

    cynic-al
    Member

    Geoff, ever thought about what holds dropouts/brake mounts on to On one, exotic, Pace carbon forks?

    bikebouy
    Member

    Deeez r’ trendin’ a da mo’

    Ben? is he gentle? ask for a discount?

    Premier Icon funkmasterp
    Subscriber

    No, Ben is a real rat.

    Premier Icon brant
    Subscriber

    Just to keep you on your toes, I think Brompton have quite short rake forks. So that needs to be taken into account too. Too much rake will lead to right twitchy steering.

    cynic-al
    Member

    So I’ve decided the Brompton needs a front disc. Ben’s lovely forks are £295.

    I’m thinking I can bodge up an old CSU or cut down some carbon or aluminium forks and re glue the dropouts/brake mount on…but I’d prefer a steel steerer as it’ll get threaded (unless anyone has seen Ali steerers threaded…did Cannondale do that at some point?). Exotic don’t so them and I’m not sure who ever did.

    Anyway any ideas welcome, or offers of appropriate forks. Or just comment about spoons or how dangerous it will be 😀

    WTD: CSU or Fork MUST HAVE 1 1/8 STEEL STEERER

    Premier Icon garage-dweller
    Subscriber

    This sounds like a recipe for toothlessness or a serious head injury.
    Why not just make them out of Papier mache and post a before, during and after video.

    cynic-al
    Member

    You’re so funny 😐 try thinking, if you can.

    Thanks Brant, more twitchiness not good.

    bikebouy
    Member

    Wo tabout, this.. angle grind the centre prong out and weld some lugs on the end, a jubilee clip for attaching bars and job, is jobbed.

    trail_rat
    Member

    nah it one of these he needs …… bromptons are only little.

    Premier Icon Rubber_Buccaneer
    Subscriber

    needs a front disc

    For better braking? As an alternative can you still get ceramic coated rims? Back in the day they made a fantastic difference to braking especially in the wet and would maybe be a more practical solution.

    simondbarnes
    Member

    Drill a couple of holes in your fork and use a couple of nuts and bolts to attach a flat mount brake on there. Sorted 🙂

    trail_rat
    Member

    make a mount out of a spoon and carbon wrap it on ?

    Premier Icon scotroutes
    Subscriber

    Make it a fixie and you’ll not need a front brake.

    Premier Icon garage-dweller
    Subscriber

    Fwiw

    I’d be nervous of most alloy steerers for threading that I’ve seen (the one on my roadie doesn’t look like the most robust material). Cannondale might have threaded them 25 years ago but I reckon they would have been a fair bit thicker then.

    Do they internally “butt” carbon forks? If so you could have a thinner leg end to contend with post cut that needs some beefing up. You may know better than i.

    One other controversial alternative approach. If you could find a suitable donor fork could you get/make up a crown+steel steerer then shorten the legs from the top and fit/refit leaving disc mount and dropouts in place?

    cynic-al
    Member

    RB ceramic rims…20 years ago in 700c and 26″ maybe!

    GD your last solution would be ideal but I could spend forever waiting for something.

    Pretty sure Cannondale did thread theirs, and, think about it, steerer diameters and thicknesses were the same then.

    Are you suggesting threading carbon?

    Anyway I got a pair of Suntour forks for £10. The weight will be offset by my new rear rack, 140gm of chinois aluminium 😀

    trail_rat
    Member

    threaded alloy steerers of days of yore were thicker.

    cannondales often had oversize forks even.

    hols2
    Member

    cut down some carbon or aluminium forks and re glue the dropouts/brake mount on

    Glue, eh? Surprised nobody’s tried that before, what could go wrong?

    Glue, eh? Surprised nobody’s tried that before, what could go wrong?

    Glue could de-bond, but it’s not a new thing, look at any number of carbon forks (On-One, pace, exotic are all glued). Lotus actually glue the elise chassis rather than weld as it’s stronger, along with several superbike manufacturers bonding their frames.

    And carbon fibre is about 30% ‘glue’ itself.

    Premier Icon flashinthepan
    Subscriber

    Lotus do it – so it must be robust, right

    Lotus do it – so it must be robust, right

    Well, errrrrrr, yes?

    CCM use it in their MX bikes too.

    Premier Icon richmars
    Subscriber

    Gluing is fine if the design was based on glue, like the Elise chassis. I don’t think it would work as well trying to glue a standard mild steel chassis that was designed to be welded.

    Gluing is fine if the design was based on glue, like the Elise chassis. I don’t think it would work as well trying to glue a standard mild steel chassis that was designed to be welded.

    True, but then most forks with carbon elements are designed to be glued together.

    Premier Icon letmetalktomark
    Subscriber

    what about a steel Pace steerer with a bolt on/in crown? Marzochhi Bomber crown and steel steerer?

    leggyblonde
    Member

    Old Alan and Vitus CX and road bikes has 1″ threaded aluminium steerers.

    cynic-al
    Member

    trail_rat – Member
    threaded alloy steerers of days of yore were thicker

    How? A 1 1/8 headset screws on the outside, a 1 1/8 stem fits inside?

    bencooper
    Member

    No, Ben is a real rat.

    Hey!

    Cut-down Pace forks would be very cool – might not fold that well because of the wider crown, and you’ll need a fitting for the handlebar catch, but they’d look brilliant.

    You can use a threadless headset on the Brompton if you use a USE Ring-Go-Star.

    I built a double disc for a Brompton once, that was silly…

    bencooper
    Member

    Or if you just want something a bit better than the rim brakes, how about a drum? Greenspeed used to make a special narrow drum for Bromptons, not sure if that’s still available, but the standard Brompton forks are also persuadable out to 100mm for a standard drum.

    cynic-al
    Member

    Interesting. I had a SA drum, not that powerful, heavy.

    Ringostar could be a winner too.

    Yup I wondered if the width.of the fork might be an issue, I’ll check it all out when I return form this trip.

    Cheers!

    Premier Icon epicyclo
    Subscriber

    cynic-al – Member
    Interesting. I had a SA drum, not that powerful, heavy.

    Depends which era it was. I find they work much better if you use good cables, ie incompressible.

    As for weight, I reckon you could shave quite a bit off in a lathe without hurting them.

    Premier Icon speedstar
    Subscriber

    Four candles?

    PeterPoddy
    Member

    Aren’t we over complicating the whole issue here? Why not just get a disc mount professionally welded onto the existing fork? Wouldn’t cost much.

    cynic-al
    Member

    Brian, a recent one. It’s 500gm over a disc brake/dynohub shitmano set up. I don’t have a lathe.

    PP – STD fork is 70mm OLD so disc would foul fork leg.

    Well, errrrrrr, yes?
    CCM use it in their MX bikes too.

    Glue can be very useful stuff if an assembly is designed to use it, but it’s probably not wise to point to CCM as a shining example of build quality…

    Premier Icon epicyclo
    Subscriber

    cynic-al – Member
    Brian, a recent one. It’s 500gm over a disc brake/dynohub shitmano set up. I don’t have a lathe…

    Nor do I, but as a fellow bodger you may appreciate how I plan do do just that.

    Remove the axle and bearings, run a big bolt through it and attach to my drill press and spin it up.

    I was planning using abrasive paper glued to a stick rather than a cutting tool just to minimise the effects of loonie H&S type incidents. 🙂

    There’s a lot of meat on the rhs flange for a start, and I reckon the drum could do with a few big holes on the vertical parts (we used to do that with motorbike brakes to improve cooling), then notch the flanges between the spoke holes.

    The brake plate could be drilled out extensively or part removed. The structural part is between the pivots, the rest is just to keep the weather out.

    The brake shoes could handle a few holes through the webs and removal of any metal not actually supporting brake lining.

    Then there’s the brake reaction arm. I’ve seen less metal on a full sized motorbike one. TY Yamahas were dead light – I may even still have one rattling around somewhere. Remove the arm and replace with a light alloy one.

    Finally for more power I’d be tempted to spend some time dressing the brake cam.

    I could take it to a mate and get him to do it “properly”, but where’s the fun in that?

    cynic-al
    Member

    Have you ever tried sandpaper/Emery on aluminium?

    You have too much time on your hands…

    Premier Icon epicyclo
    Subscriber

    cynic-al – Member
    Have you ever tried sandpaper/Emery on aluminium?

    Yup, loaded with soap.

    It’s how we got motorbike rough cast crankcases to a mirror finish back in the days before diecasting. It did take time, but the end results were very satisfactory.

Viewing 40 posts - 1 through 40 (of 52 total)

You must be logged in to reply to this topic.