Would there be anything wrong with simply drilling holes in my frame and bolting the brackets on. Sounds so much easier then the braze option, but I figure there must be a reason.
Complete wrong idea, D-Brake is so convenient !
I already have the brake though.
Yes. Your frame would break. Probably. Would certainly seriously weaken it, and not something to do unless you like injuring yourself. There’s a reason brake mounts are brazed on.
Not the brake. D-Brake is a bolt-on mount for the brake.
+1
But with some more information we could be more helpful. Rim or disc brake? Which frame are you using?
my money is on a bmx style calliper brake and he wants a hole in the crown to mount it
Uhh… not so fast.
This depends on the composition of the frame and the size of hole he’s planning to drill.
OP, can you tell us which frame you have, what type of brakes you’re planning to install, and how you want to attach them?
Drilling the frame wouldn’t leave enough metal for threads to bite into, but if you’re bolting through the frame, you might be able to make it work.
I drilled a hole in the “down-tube” of my Coker and through-bolted a caliper brake from a 10-speed. 1000 km later and it’s still fine.
I have thought of trying that caliper brake idea too.
Its a Joe Rowing like the Oregon it has a double vertical. I have a magura brake and mounts.
I would worry that the tube would crush as you would need to bolt through to the other size and there would be no crush tube welded inside the leg to resist the compression forces.
Also would the brakes even reach the rim if the mounts bolted at the centre of the legs as they are normally offset towards the inside?
just get mounts welded 
If a jobs worth doing and all that.
You don’t need to wrench the bolt down that tight. The bolt isn’t responsible for stopping the wheel… the caliper is. All the bolt does is hold the caliper in place.
I’m pretty sure you could drill holes in the frame and bolt on magura mounts and even get the brake to function
The question is whether it’s a good idea. I would suggest not
Firstly ‘just drill some holes and bolt it on’ I fear will actually be much more technically difficult Han brazing on mounts
Next with the loading on the holes from the bolts they’re going to stretch and the brakes will wobble rattle and not work so well
Honestly I think you could do it but I don’t think it will be easier ANSI don’t think it will be better
What kind of uni is it? How big is the tire?
Most uni’s can take a long reach BMX caliper mounted through the seat tube at the crown. If it’s a MUni with a big fat tire you probably need maggies. A lot of brakes won’t clear a MUni tire.
If you want to use V’s you could scavenge a brake bridge complete with brake studs from an old suspension fork, and strap it on with hose clamps. I had a setup that was made to put v’s on a frame without brazing and it was pretty much the same thing. Unfortunately, the one I have isn’t made any more, but here’s a photo:
The magura pistons are held in a split ring to allow multi direction adjustment so the bolts have to be reasonably tight to stop the piston moving, thin walled tubes will deform. maybe slightly but the piston will then become lose and move until you tighten it again and the process will start all over again
Another option would be 4 rivnuts as you only need a hole on one side and as the bolt will be tightening against itself ther would be no tube compression, as long as you don’t use the brake hard going backwards which could rip the rivnuts out you should be fine, although a brake booster might help stop the rotational force from the rim twisting the pistons and effecting the rivnuts.
Just carry a hockey stick with you and jam it in the spokes when you need to stop. It sounds like less hassle and may do less damage to your unicycle.
Either that or consider yourself a ‘purist’ and forego the brake altogether.
There’s a bike shop in Harrisonburg. The owner, a guy named Les Welch might be able to braze the mounts on for you.