Frustrating headset problem
 

I have a frustrating problem with my CAAD10 2012 headset. I recently had a warranty replacement streerer issued after a problem. But since then, I cannot get my headset adjusted properly. I'm familiar with the set up, using the pre-load adjuster first and then adjusting the side bolts. But I just simply can't eliminate play in the headset. Could it be wear on the bearings? Should I look to replace them?

Many thanks, and very grateful for any help received.

Is your new steerer longer than the original? Look under the top cap, if there's no gap between the end of the steerer tube and the top of the stem (or the top of any spacers on top of the stem) then no matter what you do with the top bolt, you won't be able to tighten the headset.

Alternatively, if you've replaced the steerer I presume you took the headset to bits. Are you sure you didn't leave out any parts while assembling the headset? As in, is the crown race still on the old steerer or something?

There is a negligible gap between the top of the steerer tube and the top of the stem. Should I look at getting some more spacers?

This ^

Just ho much is negligible?
Here is a good photo for you to see what it should look like right above Step 3

In fact the new steerer is shorter than the original. So now I'm confused :rolleyes:.

Yep. That's most likely the issue if it genuinely is negligable (as in like half a millimetre). If the steerer's meant to be shorter I'd say a spacer (or maybe a headset component) has gone walkabout.

The gap should be like 5 mm or more. Enough so you can adjust it properly.

I have taken the headset apart and I have all those parts. The only difference is the crown race is not the original one.

So I should be aiming at a 5mm gap? I definitely don't have that, more like half a mm. I presume the solution to that is to order a set of spacers and increase the gap that way?

Yes, that would be the solution. You can add them on top of the stem to keep the handlebar height the same, or underneath it to raise the bars if you like.

Great advice. I'll put the parts on order. Many thanks.

although crown races may look similar, they need to match the bearings used in the headset. if they don't match, there will be problems, IME.

Checklist:

• Are you using the correct crown race to match the lower headset bearing? Is there even a crown race?
• Are the headset bearings installed upside down? Check top and bottom.
• Are the bearing cartridges the correct spec? You need to get the right angles. There are several 'standards'.
• Are the headset bearings pooched? Time to crack the seals and clean them out? Or new cartridges?
• Does the stack of stem and spacers sit above the level of the steerer? Has to - otherwise there is no way to apply compression to the headset bearings. 2mm is just right.

BTW: I worked on a bike in June in which the headset was just wrong. There was either binding or everything was too loose. Why?: someone had installed one of the loose ball retainers upside down. In order to 'fix' this, the hack mechanic had then shoved a bunch of aluminum foil inside the bearing cavity. Pretty stiff bearing was the result.

Oh dear, well I can safely say that's not happened here!

I will update if I have further problems.

Some modern carbon forks have the crown race molded as part of the steerer. The lower bearing is in direct contact with this molded race. If you put the old crown race on top of this molded race, the headset will not adjust properly.

Also, did you put the compression ring, or split ring, back in?

It sounds like you just need an extra spacer, due to steerer length diffrence, to be able to compress the bearings properly.

go out and play...
 

http://www.parktool.com/uploads/imag...elp/fork11.jpg

top cap could be bottoming out on steerer.


Park Tool Co. » ParkTool Blog » Threadless Headset Service

Many thanks for the information so far. I can confirm that with the spacers added on, I still can't get the compression right. There is still movement in the headset. The problem for me doesn't feel like the crown race, the movement feels like it's coming from the top and not from the bottom.

Often when headsets refuse to tighten to zero play, the problem isn't an adjustment issue, it's an installation error. There may be play between the crown race (or centering cone) and the fork, or between the bearings and head tube, or simply a top centering cone that's worn, damaged or pocketed and not securing the top race properly.

Step one is to remove all the spacers and check that the lowest one is pressing the entering cone, and not resting on the top cover. If that checks out drop the fork, check crown race, and bearing/frame fits.

Getting zero play into something that's not secure is a lose/lose proposition, so checking that each part is tight and secure before installing the fork is where the process starts.

could even be a stem that is not machined properly, or that the stem clamping bolts are bottoming out.

poor machining?
 

yep.

flip(or change)the stem and change the spacers, see if that helps.