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Discussion Starter · #1 ·
Today I decided to clean and grease my fork for the first time. found a little damage up top. look like I have a few little chips right at the top. Also looks like a crack or carbon coming undone from the top. Last picks looks like a scratch or tiny surface crack running down the side.

I'm not too familiar with carbon so just wanted to check out if this is normal. I should mention I don't have a torque wrench and have been playing with my stem a bit.

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'brifter' is f'ing stupid
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You 'greased your fork'? Why on earth would do that? The bearings maybe, but this comment makes me think you're just using the wrong terminology. The steerer tube looks fine, I wouldn't worry about it as long as it's not too long (too many spacers below/above the stem).
 

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Discussion Starter · #3 ·
You 'greased your fork'? Why on earth would do that? The bearings maybe, but this comment makes me think you're just using the wrong terminology. The steerer tube looks fine, I wouldn't worry about it as long as it's not too long (too many spacers below/above the stem).
Yeah I meant bearings. Thanks

I do have a few spacers below the stem, none above. Whats a safe of spacers below?
 

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From the pictures, I don't see any major issues of concern with that steerer tube.

I do have a few spacers below the stem, none above.
You should have at least one small spacer above the stem to allow you to get the proper preload on your headset bearings. When you tighten the headset bolt you are pulling the steerer tube up into the bottom of the stem cap, and thus you need some space between the two to give you leverage. A 2-3mm spacer should be enough.



Whats a safe [amount] of spacers below?
Different fork manufacturers give different answers to this question, but in my reading the consensus seems to be no more than 40mm.
 

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Discussion Starter · #5 ·
You should have at least one small spacer above the stem to allow you to get the proper preload on your headset bearings. When you tighten the headset bolt you are pulling the steerer tube up into the bottom of the stem cap, and thus you need some space between the two to give you leverage. A 2-3mm spacer should be enough.
This is not always the case? Cannondale's site says not to put spacers above the stem. I think 55mm is also there limit.
 

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This is not always the case? Cannondale's site says not to put spacers above the stem. I think 55mm is also there limit.
Perhaps the Cannondale headset has a special stem cap that includes some sort of built-in spacer? I'm not sure. My understanding was that in general you always need a tiny bit of space above the steerer tube. And I can't see how a small spacer would cause problems.

But if Cannondale says otherwise then clearly I'm wrong in this case. Sorry for any confusion caused.
 

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On most, maybe all, Specialized carbon forks and internal plug, their design specifically requires NO spacers above the stem. The plug is a design that sits flush with top of steerer tube, and it resists crushing when the stem is tightened. This plug also gets automatically positioned in the correct vertical position.

Generic advice on the internet can, and will, get you into trouble.

Many, perhaps most, bike shop employees can be unreliable sources of information.

Follow the Mfr's recommendation.

Reminds me of an article on The Onion satire site a few yrs ago:
"The Information Age was dealt a stunning blow Monday, when a factual error was discovered on the Internet."
;-)
 

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Fair enough.

But for the record, I wasn't merely repeating stuff I've read. I'm no pro mechanic, but I've built a half dozen bikes from scratch and maintained half a dozen bikes (mine, my wife's, a coupe of friends') over the past few years. So I'm perfectly wiling to admit the limits of my knowledge and experience (as I did above), but I wouldn't try to provide someone with advice merely by repeating something I've read elsewhere.

I don't doubt what you say about Specialized (and perhaps Cannondale) having special setups.

Coincidentally, I just picked up a brand new Specialized Langster that I'd ordered from a local shop. When I got it home I immediately noticed that the headset was loose (they also failed to center the front brake caliper, and just plain lost the rear brake caliper and lever – I'm waiting on those). There were no spacers above the stem. I loosened everything up, and it was a mystery to me how the headset bolt could pull UP on the plug to create proper preload on the bearings. I moved one of the 3mm spacers above the stem, and it loaded up (without binding it all), just perfectly.

I'd be curious to read more about *exactly how* the setups that have no spacers above the stem provide the preload. You mention "resists crushing," but that doesn't explain how leverage is provided that pulls everything tight. On a standard setup, if you tighten the stem cap without a spacer then you are simply pushing the cap down onto the steerer tube, not pulling up to create preload on the bearings.
 

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Don't know about the Langster, but down below is a cross-section pic of how Spesh's carbon forks are supposed to be assembled. This is a few yrs old, don't positively know if it's still exactly the same setup.

Note the top of steerer tube, with its special flush sitting internal plug, is supposed to be 3 mm below the top of stem. When you tighten the cap, the force is transmitted thru the stem to the head tube, thereby "pulling up" the fork.

Like the mad proliferation of bottom bracket designs, it seems there are more & more proprietary or "unconventional" headset designs appearing.

It's more important than ever to consult the Mfr's actual tech documents.

I know one well-regarded head mechanic at a local bike shop, who didn't keep himself up-to-date on Mfr's spec. I knew of several late model Campy 11-speed installs he did, that were simply wrong.
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"Forks with carbon fiber steerer tubes: Once the initial stem height
is achieved, make a mark on the steerer tube at the top of the stem.
The actual cutting line must be placed 3mm below the mark (to make
room for the Specialized 48mm Long Expander Plug. See Fig. 2)."


Text Line Font Parallel Rectangle
 

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Don't know about the Langster, but down below is a cross-section pic of how Spesh's carbon forks are supposed to be assembled. This is a few yrs old, don't positively know if it's still exactly the same setup.

Note the top of steerer tube, with its special flush sitting internal plug, is supposed to be 3 mm below the top of stem. When you tighten the cap, the force is transmitted thru the stem to the head tube, thereby "pulling up" the fork.

Like the mad proliferation of bottom bracket designs, it seems there are more & more proprietary or "unconventional" headset designs appearing.

It's more important than ever to consult the Mfr's actual tech documents.

I know one well-regarded head mechanic at a local bike shop, who didn't keep himself up-to-date on Mfr's spec. I knew of several late model Campy 11-speed installs he did, that were simply wrong.
.
"Forks with carbon fiber steerer tubes: Once the initial stem height
is achieved, make a mark on the steerer tube at the top of the stem.
The actual cutting line must be placed 3mm below the mark (to make
room for the Specialized 48mm Long Expander Plug. See Fig. 2)."


View attachment 314806
Thanks. Very helpful.

And this makes sense: Specialized is basically saying to cut the steerer tube 3mm short, of the top of the stem, thus using the stem itself as leverage to load the headset bearings properly. I guess specialized stems are designed to work this way.

It also explains what my shop did wrong: they did NOT cut the steerer tube 3mm short. They cut the steerer tube so that it reaches to the top of the stem, then put the stem cap on top. When they tightened, they didn't get proper preload.

So I agree with you entirely about following manufacturer specifications. But in this case it's important to specify that there are two elements of those specs and they must go together: 1) cut the steerer tube 3mm below the top of the stem; 2) put the stem on top of the spacers (with no extra spacers above the stem).

(Actually, for the record in my case: the Langster has a carbon fork with an alloy steerer, so the above rules don't apply. The shop should have put a spacer above the stem.)
 

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Discussion Starter · #11 ·
taking a closer look at whats happening on my bike, I think I like the spacer on top of the stem. Right now with no spacer the stem is a little above and its being tighten down. Even after tightening there is still a little bit of the stem above the steerer. I guess this is why you use a spacer on top?

Should I just keep it as is?
 

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taking a closer look at whats happening on my bike, I think I like the spacer on top of the stem. Right now with no spacer the stem is a little above and its being tighten down. Even after tightening there is still a little bit of the stem above the steerer. I guess this is why you use a spacer on top?

Should I just keep it as is?
The steerer is to be a coupla\few mms. shorter than the stem or spacer, whichever is at the top of the pile.
 

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'brifter' is f'ing stupid
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If the expander is like a lot of the ones Cannondale use then you don't need a spacer if the fork is cut a couple mm shorter than the top of the stem. The top cap has an extension that extends down into the steerer and keeping it from being crushed. Most bike companies don't use this type of expander and a lot want you to put a 5mm spacer on top for whatever reason... probably because they don't trust shop mechanics to accurately cut a steerer 2-3mm below the top of the stem. If you cut it shorter than that it can get crushed when you tighten the stem bolts.
 
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