My latest hare brained scheme
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 😀
Posted 6 months agogarage-dwellerSubscriber
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?Posted 6 months ago
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 😀Posted 5 months ago
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.Posted 5 months ago
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.Posted 5 months agobencooperMember
No, Ben is a real rat.
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…Posted 5 months agobencooperMember
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.Posted 5 months ago
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?Posted 5 months ago
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