Originally Posted by 79pmooney

The flip side here. Replace that fork (any fork) BEFORE it breaks. I didn't. It cost me my education, half a decade of my life, a lot of money and far more in earnings after. The longer your fork has gone, the more important this is.

Failure mode is a real part of this. Forks that suddenly become two or more separate pieces are far more dangerous than forks that do it slowly. My three fork failures: Aluminum. Broke at the crown without warning. Starting under the crown race so finding it through inspection was impossible with either X-ray or removing the race. (See the preceding paragraph.) A cheap steel fork that broke clear across mid-blade. I noticed it riding home from work. Bike was still ride-able with just one blade so I continued the next mile home. (Bike had a LowRider rack. Break was just above the U-bolt - no braze-on. The LowRider might have helped stabilize the lower blade after the break.) The original fork of the custom ti bike of my avatar photo. Columbus SL built by a master and plated with nickle. Never got the required heat treat to drive off the embedded hydrogen atoms.

At 8000 miles, that SL fork cracked 2/3s around just below the crown on one blade, 1/3 of the way on the other. I was very lucky. That was happening as I started down a 2000' descent. (I had someone looking after me that day. Plan was to bomb the fix gear down in 42-12 and fly around a corner I love but have to brake hard for upon entering. Perfect pavement, banking, never debris so a late hard brake is a blast. Well, at the top of the mountain, I had issues with the lockring, tiny cog and chain. It kept going loose, then tight. Finally just set the chain to too loose and moseyed down so as to do now damage to anything 2 weeks before Cycle Oregon. 15 miles later the bike started bucking ever time I touched to front brake. Got home, saw the cracks and walked into the house shaken to the core. BTDT.

The fork you see in that photo is a rush job replacement. 531 with a deeply scalloped crown. Conservative to the max. Builder finished the build 7 days after it broke. (He had to order the 531 and it took a while.) Painted it with model paint I picked up at a hobby shop. A week later it was off the rural Oregon and that photo.

To this day, I consider that avatar bike a really "good" bike. It saved my butt. Provided a trivial mechanical when I really needed it! That fork breaking wasn't its fault. You simply have to heat treat high strength steel alloys after nickle plating. Common knowledge in the plating world. Plater knew. His rate for the heat treat was $60. He said nothing. We'd have paid it happily if he'd spoken up. (And shared blame here - I chose a minimalist investment cast crown that the builder assured me was plenty strong. He landed some SL blades (I was thinking 531) and I said yes. So - that crown with no scallops and thin tubing = a lot more stress. Builder knew that and did absolutely beautiful brazing. (I go t to see what no one ever sees - the braze around the inside of the crown. Looked like a perfect machined radius except with the matte of a braze that's never seen a file.)

My forks now - (1) and perhaps two more are 531 on my three customs. (Non are "stickered". Peter Mooney wouldn't when I ordered mine unless you paid extra so he could select what he felt was the best tube for the application. I simply trusted TiCycles on the next. The third custom is that avatar.) I also have a stock 4something 1983 Trek. Hi-ten probably. Pro-Miyata with Miyate Chro-Mo. Raleigh Competition stickered 531. Only slightly radical fork blades are on the Miyata which are squeezed and slightly aero but Miyata's record on high end '80s race bikes is rather impeccable.

I'll pass on (hopefully from other causes) before I ride a CF fork because of its failure mode and I'd always have that "what if" in the back of my mind and in my dreams. If I didn't know the consequences first hand it would be a different story. (And like that fork of mine that cost me so much, CF forks have workmanship that is critical where it cannot be seen without testing or destruction. Doesn't help that I used to build fiberglass boats and know first hand the shortcuts that get you to break time sooner or allow more to be built and keep sup' happy.)