robbyville

Trying to get my headset right (integrated) carbon steere tube. Roughly 4cm of spacers below the stem. Steere is carbon and I bought a decent expansion bolt and top cap that measures roughly 3cm in length not sure if that matters or not. How the heck do I do this so there is no play in the headset? Do I keep the stem on the steerer loose tighten the top cap and expansion down then tighten the stem on steerer? Does itatter how long the expansion bolt system is compared to the length of the steerer tube below the stem?

Challenged, please help!

svtmike

the expansion plug is meant to support the steer tube against the clamping force of the stem. to do that, it must be at least as long as the stack height of the stem clamp. besides that, it serves the same purpose as the star nut in an alloy steerer. there are is a hex socket in there that you use to tighten the plug in the tube.

install the plug -- it will be tight in the steerer. then install the spacers and stem, using carbon fixing paste on the stem clamp. preload the headset as usual with the stem cap, and tighten the stem clamp to spec.

you are running a pretty high stack of spacers. there will be a stress riser at the headset and at the stem bottom. 40mm is at the outside edge of the limits i have seen spec'd.

here is a specialized instruction that covers the finer points.

https://cdn.specialized.com/OA_MEDIA/...n_Guide_r2.pdf

Kimmo 

You mean an expansion plug; expansion bolts belong in quill stems.

Yeah, that. The expansion plug just needs to be positioned so the bolt can pull down on the spacer above the stem.

You are running a small spacer above your stem with that carbon steerer, aren't you?

Also ensure the top cap isn't bottoming out on the steerer.

And you'd get more replies for such a query in the Mechanics forum.

RoadMike

put your front wheel on the fork. insert fork into frame (make sure it isn't backwards), set the bike down on it's wheels, put on the spacers, then put on the stem, tighten the expansion plug, the put on and tighten the top cap, then align and tighten the stem. this should ensure that the fork is seated properly in the headset.

The expansion plug should be lined up with where your stem is going to clamp on to the steer tube. Hope that makes sense.

fa63

Insert the expansion plug into the steerer; make sure that it requires a little effort to insert, then tighten it to the fork manufacturer's recommendation. Put an appropriate amount of spacers under the stem, then install the stem, and put a 5 mm spacer on top of the stem (this is my personal preference). Then install the top cap / bolt, and tighten the headset with the stem steerer bolts loose until you take all the play out. Once everything is nice and snug (but not too snug), tighten the stem steerer bolts, then give the top cap bolt just a nudge to firm it up.

There are many online videos that show this process, too.

P.S. Looks like I type slow, whole bunch of folks beat me to it...

Kimmo 

To set the bearing preload, ensure there's no rattle by rocking the bike with the front brake on, and make sure it's not too tight by picking the bike up and tilting it to swing the bars.

knowledgdropper

It's not directly apparent from your post, OP, so I'll mention it now. Expansion plug gets installed first, independently from the top cap.

Here's the article that I referenced when I did my first one a few years ago. Scroll about halfway down for the expansion nut portion of the article. There's a link at the beginning of the page that covers steerer tube sizing, as well.

As far as headset play, you've got it right, as far as I can tell. With the bike on the ground, keep the stem bolts loose and line up the stem with the front wheel. Tighten the top cap bolt (I hand tighten it fairly snugly). Tighten the stem bolts to spec. To check, I squeeze the front brake and rock the front end front-back, side-side. I keep my other hand feeling for play at the headtube-stem junction.

Good luck & have fun!

Kimmo 

Yeah, sometimes this can reveal a tiny amount of play you wouldn't otherwise feel until you're on the bike.

robbyville

Ok thanks guys, ill try this in the morning. Fwiw the expansion plug I bought is not independent from the top cap (or at least the top cap bolt does not thread into the expansion plug bolt it seems to act as one bolt for the entire shebang) Bought from fairwheel. Not sure if it makes a difference.

https://fairwheelbikes.com/tune-gum-g...lug-p-310.html

coasting 

1) Put the expansionsion plug into the steerer, preferrably here the stem is. This can be very fiddly.
2) Assemble the spacers and stem. Make sure you have a spacer above the stem. This ensures the stem clamps fully ontot he steerer and doesn't damage the end of the steerer.
3) Ensure that the top of the spacer above the stem is about 3 to 5mm higher than the steerer end.
4) Put the top cap on and screw the bolt into the expander plug. Tighten until there is no play in the fork. Grab the front brakes and push the handlebars forwards and backwards and feel if there is play.

knowledgdropper

Haven't seen that yet. Looks like a simple, solid design. Your Ridley didn't come with one already installed?

robbyville

It did come with one but it weighed in at 55g and my ego got the best of me, it was a chunky monkey and I wanted to be on a diet

robbyville

Somehow bottom nut from the old one is stuck at the bottom of the steerer trying to fish it out before starting with the new one

bianchi10

Flip bike over and it should fall out

robbyville

nope, somehow it's wedged in at an angle. Not sure if I did it somehow or the guy who cut my steerer yesterday hmmmpph

Campag4life

Forgive me robby...but that expander is a cheesy design and no wonder it is stuck in your steerer because it is rubber and short walled and can cock.
You will have to fish it out...use a piece of coat hanger with a 3mm hook on it...and a flash light.
Buy a better expander....lots on the market. Specialized makes a good one that won't fall in and and is 48mm high and will help support the carbon steer tube.

bianchi10

Campa...the OLD one is stuck. AND the gum gum expander is a good plug.

I know you are working on fishing out the old one right now but when your done, take a look at the top cap and gum gum again. The top cap should screw into the top of the expander. Thrats what expands it in the steerer

robbyville

Well no luck fishing, the thing is wedged in tight and I'm worried about the carbon if I whack, etc. Not sure how it happened, based upon how deep it is I think it may have fallen yesterday or something. I'm going to have to leave it in there. Took off the fork and everything. this turned into quite the chore in an otherwise simple build.

At any rate, Bianchi, checked the instructions on the gum gum again and I have it right, just the one bolt that goes into the threaded plate via the top cap. that being said, just finished re-installing the fork and adjusting the headset with the gum and all is well. NOw I just have to replace one piece of derailleur housing where I didn't leave enough room for fitting (thought I had) and then tape the bars. I'll post final comments on my build thread when done. maybe on hot or not but I'm kind of embarrassed by the fitting (added 2mm in spacers and flipped the stem, in fact I have to order a new shorter stem as well, yuck)

svtmike

Fixed it.

bianchi10

How does your top cap stay on if it does not screw into anything?

robbyville

it screws into the allow wedge that pulls into the silicone ring, essentially it replaces one bolt screwing into another, the entire system has one bolt instead of two. I know, not explaining it well

I should mention that the photo on the fairwheels website has it wrong though. The cone shape on the bottom threaded alloy plate goes up into the silicone ring so that it expands as you tighten the top cap down.

svtmike

If you get that thing out of there, go back to the one that was supplied with the bike for a couple of reasons:

1) The stock plug can't be dropped or irretrievably wedged into the steer tube.
2) The stock plug will support the entire clamping surface of the stem.

I agree with Campag -- that gum-gum thing is a terrible design. I hope the carbon isn't compromised by the wedged part. It would be at the worst possible spot -- right around where the stress riser will be from the stem clamp.

bianchi10

You guys realize that he said it was the STOCK expander that got stuck right? The tune gum gum expander is used by thousands And works well.

svtmike

I couldn't find where he has specified unambiguously which one is stuck. He did provide the link to the photo of the tune expander -- which would be irrelevant if the other were the one that is stuck.

Edit -- nevermind I found it.

Still think the tune design looks terrible for the reasons cited.

Since he mentioned someone else cut the steerer and installed the old one -- I hope that isn't actually a star nut installed in that carbon steerer.

robbyville

no it wasn't a star nut, it was the original expansion plug that came with the frame. Even the guy said he had never seen anything quite so bulky, not sure how it happened but it's really stuck, only the knurled end part though right at the bottom it's not budging (it's also cockeyed so can't get a bolt into it and then pull out).

The gum design seems pretty good, it definitely covers all the area where the stem clamps onto the steerer well. certainly a heck of a lot more simple than the stock one!