'Home made Drop Brakes'

Thinking about giving this a go, source from sheldon

http://sheldonbrown.com/home-drop.html

Have just installed the more expensive deep drop brakes on the bob and they just dont feel that much better.

Anyone tried making these?

Does this mean you could use the Rival brakes? I vote why not in that case!

yep! dont look all that pretty though unfortunately!

I've done it a couple of times, using T-shaped plates rather than flat bar. It works, but it's not going to make the porn thread.

god dam frame made for god dam huge wheels..

I've done it a couple of times, using T-shaped plates rather than flat bar. It works, but it's not going to make the porn thread.

Wouldnt happen to have any lying around ;D?

I've reinforced a rear bridge on a vintage bike with plates and bolts, a similar process to the one described, and I've had no problems. It's not particularly pretty, bt does the job spot on.

http://www.flickr.com/photos/8379107@N03/6378676163/in/photostream/

http://www.flickr.com/photos/8379107@N03/6378665257/

looks pretty smart..

just need some tools..

^ that looks handsome, but I'd want it to be deeper and bolt over both sides of the bridge (i.e. built in two halves which clamp over the bridge) - at the moment, it's relying on the tension from the nut to stop it rotating, but if it were bolted all the way through it'd be impossible to budge. There's no point in not making it as stiff as possible, after all.

well the nuts curved so i guess that helps a fair bit keep it in place

Well yes and no - the force would be rotational, and the axis would be where the bolt, bridge and bracket intersect... the surface of the bridge is very nearly concentric to, and only a few mm away from, that axis - so it provides minimal support and an amount of friction Essentially having a bracket on the other side would provide support against the rotating movement of the block, and also provide a hell of a lot more friction to stop it rotating in the first place.

It'd have been only a very slightly larger amount of work to make it far, far stiffer. The brake arms themselves are almost certainly the most flexible point in the whole system, but for the sake of an extra 30 minutes, I don't see why you wouldn't try to eliminate as much flex as possible.

*not a professional engineer.

You're right that flex should be avoided, and the further the flex is from the pad the more effect it'll have.

Relying on the bolt to prevent rotation is just the same as a normal installation with no drop bolt. (Though with slightly larger torque from the larger bridge to pads distance.) A friction-clamp design would work better with bolts above and below the bridge, but because the diameter of the bridge is so small the forces from the torque are probably too large to trust to friction. Curved washers just help avoid crushing the tube.

Sheldon's 2-plate design has a parallelogram effect that resists twisting even as the plates flex, but with the tiny extra drop here that's not needed.

Yeah. Since the arms are the flexy bit, the owner would get better braking by making the drop bolt as long as possible and moving the pads up on the arms, thus effectively shortening the arms. Ugly/mudguard clearance, though.

if i managed to get hold of/make 2 of those ^ (see pic) for the front and back of the bridge and then more 'flat plate' style ones or the front and back of the drilled fork it

that'd be advisable?

To be clear: in my opinion the design in the flickr links is fine. Lae's suggestions would add bulk without significantly improving it.

For a longer drop, something incorporating Sheldon's 2-plate design and/or 36x18's T-shaped plates which brace directly against the seat stays would be better.

On the front i'd be more concerned with making it as sturdy as possible as front brakes can generate more force, and failure at the front is more dangerous.

Oh please, it costs a couple of grams in weight and nothing in terms of clearance, even a slight increase in stiffness is worth it.

Anyway, this:

Won't work on the rear, but it'll be very stiff (assuming tight clearance), and visually unintrusive.

@,@ thatd require some serious tools/workman ship, if you had the workshop for it thats a great solution though

Assuming the inside of the steerer is round enough (no brazing pins in it), all you'd need to do is get your local friendly engineering company to turn down some stock to the right diameter, which'd cost about a fiver. You could drill the holes yourself. You might even get lucky and find some tube that fits anyway.

I had my local metalworker make this for me out of two bolts, welded together then ground down. He did it in about 5 minutes and charged me about a fiver. Worked like a treat on my old forks, never had any problems with it.

Unfortunately I no longer have the forks so can't show you it in action, but it did work well

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Wouldnt even know where to find such a person! gotta be someone in the city,

might see what ryan at oakcycles can do when i take my frame down for respacing