ScreamingB

Today i removed the stem and came to find out that there's a huge gap between the carbon steerer tube and the top of the expander plug. I unscrewed it then screwed it back as per the spec (4Nm) but the gap is still the same. However, there's a 3mm gap when the stem is in place. Is there anything to worry about?
Please advise.

Thanks

DorkDisk

That plug needs to be flush with the steerer; sometimes the plug pulls out when attempting to preload the headset, watch for this. Grease goes on the beveled part of the plug but nowhere else, especially not in the steerer.

Carbon doesn't like being clamped near the edge, so the stem then goes flush with the steerer. To get the gap we need, we add a 5mm spacer on top of this, then the cap.

ScreamingB

If the plug is flush, wouldn't this increase the gap when the stem is in place? Also, the expander seems to be stuck at that location and I'm not familiar enough to relocate it.

Thanks

DorkDisk

The top of the stem must be installed flush with the steerer, not above the steerer.

Take it to a shop.

ScreamingB

I loosened the 8mm hex key, placed a credit card on top then smashed it 3 times with a bottle of shampoo and the expander came lose. But I could not pull it out even it's lose. So I just tightened it to 4Nm and it's all good now. Stem gap is now 6mm I hope it is ok. Thanks.

cxwrench

ftfy.
That's too much gap between the steerer and stem IMO. You need to get rid of 2-3mm of spacer below the stem.

ScreamingB

What is the side effects of too much space? I will swap the 10mm spacer with a 7mm

Crankycrank

I think (but maybe I'm wrong) that cxwrench may be referring to the fact that your top stem clamp is only half supported by the steerer tube/expander. Lowering the stem a few millimeters will give it full clamping support and less likelihood of the stem forming a crack at that spot over time. Maybe a little too cautious but could be a very expensive failure if not.

Camilo

Set up the spacers above and below the stem so that the stem clamps are supported internally by the plug. Your fork manufacturer might have diagrams and instructions which you should follow.

You can find long plugs which give you more flexibility in achieving this.

ScreamingB

What puzzles me is that this is a new bike which means the factory did not install it properly. The top cap screw is also very tight when I removed it the first time.

Is it normal the fork clunks at sudden front hard brake? I rocked it back and forth after tightening the stem screws and couldn't eliminate the clunk.

shelbyfv

Why?

ScreamingB

Felt something is not right after flipping the stem. Didnt even realize the top part of the expander was stuck to the top cap screw when i first took it off. So, taking it off apart to see if there's anything i did wrong, then noticed the big gap.

SoSmellyAir

This seems to be wrong; the top of the stem should be 2mm higher than the top edge of the steerer tube. I agree with CXWrench's correction.

SoSmellyAir

No. Perhaps the headset is loose. Follow the instructions here:

How to Fix a Loose Threadless Bicycle Headset - Road Bike Rider Cycling Site

shelbyfv

It seems all was OK until you dismantled it. No problem with mfg installation. I suggest you take it back to your dealer, they can quickly put it back to right.

ScreamingB

Haha.. the sequence of events should be

1. Bought the bike
2. Took bike for first ride and noticed fork clunk when going up hill. Got my back hurt too due to the aggressive negative angle stem.
3. Flip stem, when removing the top cap screw, it was very tight. Top part of compression plug was stuck with the screw. I didn't know it because i thought that's normal. (Never seen a compression plug before)
4. After flipping stem, fork still clunk. Decided to disassemble headset. To my surprise, the top cap screw detached from the top part of compression plug. This lead me to notice the big gap between the steerer tube and compression plug.

So I'm pretty sure i didn't mess things up. The top cap screw was overtightened in the shop thus pulling the compression plug up. 🤩

Now after i hammered the compression plug flush with the steerer tube, the stem gap appears to be too much (~6mm). Isn't this obvious the factory mess something up?

Note: I cannot bring the bike back to the shop due to covid lockdown.

shelbyfv

Good luck

ScreamingB

I actually did this.. the clunk only happens when i triggered the front brake and pull the bike in reverse. If i didn't do this, it will only clunk one time and won't happen again.

ScreamingB

Current spacer height 24mm (7, 7, 10)
Ordered the Spank spacer set which consists of 12mm, 6mm and 3mm totalling 21mm

Going to swap them when they arrived 👍🏼

CliffordK

What is the bike?

Many bikes have really tall steer tubes when new. It may have been your local dealer that cut the steer tube,and left the plug sticking out.

ScreamingB

Giant Escape 1 Disc. Possible, but I believe the bike is almost fully assembled in the factory. Watched some unboxing videos and the stem is already installed when they remove the bike from the box.

ScreamingB

Found the issue. It was the fork not fully seated on the hub. Reseated and all good 👍🏼

CliffordK

Interesting bike. You're probably right, not custom configured at bike shop. I guess I was thinking possibly full carbon frame with the carbon fork.

It is odd that their spacers and steer tube length don't match well.

I'm surprised it has front and rear quick release hubs. Make sure the front QR is locked down tight.

SoSmellyAir

Congratulations! A second thread in the Bicycle Mechanics subforum with a happy ending within a week.

Did not expect a QR wheel on a new bike with disc brakes; thought that was only for bikes made a few years ago.

ScreamingB

Thanks. What's up with QR wheel on new bike with disc brakes? Is there anything i should watch out for?