I have a Traitor Ruben (cross bike with discs). the bike is 4130 steel as is the fork and I want to move the front brake routing to inside the fork instead of on the back side of the blade. Is it a terrible idea to drill into the fork crown and out of the leg a bit lower?

Without adding something around the hole you will create a stress riser. Not something you want on a fork. You could have a framebuilder do the work.

like this? but drilled out and brazed onto the crown then something similar for the blade?

That would work for the top and one of these for the exit.

right. so with the right support at the holes it is very possible correct?

Craigx3- Why are you considering this mod? Is there some problem you're trying to fix?

The shop I work for is very involved with the (meager) local CX community. I get to clean and tune (comparatively) lot's of CX bikes. Any thing that make access to cables or allows entry to the frame's insides (by mud/water) is a no-no in my experience.

The only internal cable routing I might consider is the designs which have a noncorrosive tunnel/tube containing the cable/housing. This internal tunnel is brazed to the frame tube at both ends so none of the environment can get into and stay the frame tube. Still this would make lubing or cleaning off the cable a real pain. With all the riders that I've seen that have aggressive sweat or winter salt exposure cable rust/grit collection is a common issue I deal with.

Lastly think about the cable's route into the crown/blade and whether a fall down might rotate the fork enough to have the cable kink on the down tube. Andy.

tapered fork blades have issues with disk mounts in the first place, so I don't think it's a good idea. I've seen enough that I'm not going to build any bikes with disks and tapered blades. I know people do it successfully, but that's not good enough in my estimation. Those reinforcements are largely cosmetic. Most cables are run through tubes that are not highly loaded.

my reasoning is to clean up the front end of the bike a bit and gain some experience with like things. I would love to get into frame building but diving in with little money leaves me in a tough place. If it is not safe I don't want to be pushing my luck as I do not own a car so this is my transportation.

If I could just find a builder near by that would let me apprentice with them I would want to start chopping and grinding at my own bike haha.

I would rely on the advise of others here instead of mine. Especially with this being your only source of transport.

you aren't going to be able to find someone to apprentice with unless you are really lucky. If you were that lucky, I would advise buying a lottery ticket and winning enough money to hire an experienced framebuilder. There are plenty of free or cheap bikes to chop on in my area, I'm guessing that's true in most places if you look.

aye, good idea.

And that a fork is the only part of the frame not held by brazing/welds at both ends. Meaning that if the crown cracks, and you don't notice it in time, the only thing keeping the front wheel pointing where you expect it to point is the dropout/axle QR. I have seen too many QRs not hold even when both sides of them were solid. My only fork failure happened at a walking pace. I was very lucky as only a few miles before I was going over 40mph in traffic. Andy.

Would this work for a low rider front rack in a Chro-Molly fork?

People have used bottle boss fittings for low rider racks. There are low rider fittings that go all the through the fork blades too

Thanks, I was thinking through bushings brazed on each end would make the fork a little stronger after drilling.

here is a link to a low rider boss: link

Here's how I've done a low rider mount a few times. This helps widen the top portion of the rack to match up with the hoops's spread. Also makes more stand off clearance for the bag hooks. It's silvered on. Never had a problem even after 25+ lbs on the low rider and dirt roads. Andy.