Ratzinger

How can you tell if a frame and headset are damaged?

Big damage, dimples etc...are obvious. I have a steel bike and the steeling is a bit off, not easy to ride hands-free, and the fork seems slightly bent.

I hoping a replacement fork will fix the problem. How can you tell if there is a deeper problem with the frame and headset?

Thanks

andr0id

The only real way to tell is to take it apart and have a frame builder put it on the jig and check it.
Other than that, you'll just have to see if you are happy with the way it rides no hands once you replace the fork.

Ratzinger

Thanks, that's what I'll do. It appears as though one side of the fork is bent back, I'm hoping it wasn't a strong collision. The bed isn't too obvious. I'm just hoping that it's possible that the fork is bend without it having affected the rest of the frame.

SquidPuppet

Look on the underside of the down tube. Look at it near where it meets the head tube. Look for wrinkles in the paint and indentations. Run your hand over it and feel for distortion in the tube.

JohnDThompson 

The "string test" will tell you if the rear triangle is in alignment with the rest of the frame. A shop tool like the Park FT-4 can check for fork blade alignment.



And eye-balling the head tube against the seat tube may show if the head tube is out-of-axis with the seat tube.

When in doubt, take it to someone with an actual surface plate or alignment table to get it checked professionally.

CliffordK

I had a bike a while ago that I could never quite get he headset in adjustment. It was like there was a sweet spot straight ahead, then it became tight when turning the bars.

Recently I've started wondering if that was a sign of hidden damage.

mtnbke

+1

I took a bent fork to Mark Nobillette. He bent it back, checked it out, and charged a very reasonable fee. Peace of mind is priceless.

habilis

Could this have been due to "indexed" head tube bearings? I overhauled a head tube recently because the steering felt slightly notchy. Examining the races, I saw evenly spaced shiny spots. After cleaning and re-greasing, and replacing the ball bearings, everything seems fine. (I showed the races to an LBS mechanic who also thought they were salvageable.)

HillRider

Or it was evidence that the faces of the headtube weren't parallel. Facing the headtube might have eliminated the problem.

CliffordK

I think one of the common places for the forks to bend is the steer tube which would otherwise be hidden in the middle of the head tube. Unfortunately, I don't have the bike I remember that problem with. But, a bent steer tube could well affect the headset adjustment.

The lower headset crown race on my Colnago is getting pretty badly washboarded, but it doesn't seem to affect the steering. I should probably either polish the crown race, or replace it. Maybe for the next rebuild.

CliffordK

That may have been it too. Or, perhaps a combination of problems. I think one bike that had touchy steering had been powdercoated prior to my getting it.

Ratzinger

I'm going to change the fork, replace bearings, and hope that it feels good. Taking it to a frame builder or another expert is a possibility since I really like the bike.

Anybody know if there is someone good with frames in Toronto? I haven't come across anything yet.