Quicktips - Fork steerer compression plugs 

One of the few video's where the presenter actually knows what he's talking about and demonstrates it in a clear understandable way!! Well done Sir!

That is amazing; I can't believe how much the steerer expands when the plug is tightened.

I can't get enough of this content! Awesome stuff Raoul

Amazing how far behind the knowledge curve the fork design "engineers" are in their efforts to create a safe bicycle experience.

Good to see you back.

Great video Raoul! Good to see you getting the time to get more content up online. Much appreciated!

An excellent video as always with high value informative content - Many thanks Luescher Teknik 🙏

This is the best explaination of a steerer plug ever, thank you !

Wow your videos are really informative and really honest which is very rare in the cycling community which just promotes stuff to make money... i salute you sir!

This is great. Ages ago someone recommended I use Specialized plugs because it took minimal torque to make them stay put in the steerer. I'm glad you like them too.

Thank you for putting this up. Keep it up. No need to edit when you are straight up with the facts. BTW I opened up my Garneau steerer to find a beefy 1-piece aluminium plug inside. Very happy to see this.

Great video. My the plug that came with my Felt frame would easily slip, even with paste. A different bike shop was aware of this and threw it away. They replaced it with a longer plug that contacted the steerer over its whole length.

My Cervelo steer tube sleeve came apart eventually and I went with a regular compression plug. 25,000km, without problems. Great video Raoul

Very interesting content as always, thanks a lot for spreading your experience !

Very useful tips, thanks.

Very informative. Thank you!

Great info.

Great. Super info! Thx!

Good video, i had cannondale one couldn't get it to fit correctly, luckily i bought a new one, same one you said was good

This is gold!

Ive always dreamed of having a roadbike. And your place there is like my heaven. Here in the philippines in order for you to have a reasonable road bike is pay like a lot of money! Dreaming of cycling someday! Love you tips and they are very helpful and gives me knowledge. You inspire me

Great tips.

I'm very happy with my Pinarello insert. Smart.

Great overview!

Excellent information, and examples!!! Thank you !!!!! :-) :-)

superb

Went to my parts tote and binned a couple. Deda has some nice units that seem to meet his criteria.

great video, i had a cannondale plug and it constantly gave me trouble , the stem was coming loose or the headset would creak if i tightened the topcap to about 1.8-2 nm, thrown it away and replaced it with a "heavy one" and never had an issue since

I made some simple aluminum plugs, just use epoxy to glue it, super strong and no issue so far.

AWESOME!!! Haha got a pick up those plugs! We should find you someone who can film and edit for you because your knowledge and analysis is EXTREMELY awesome!!!!! Please cut up the Argon 18 and Giant for us :)

Perfect timing, I just bought a new stem for my bike, and when I opened it up I had a carbon steerer tube. going for a ride this afternoon to test it out. 5nm just doesn't feel that tight for something like this but I cannot force it to move.

Yes! I have specialized compression plug Raoul! I am finally not gambling with the baddies.👍

Slightly off topic, but could you comment on the practice of cutting the steerer a few millimeters above the stem and using a short spacer there to provide clearance for the stem cap. I've read that this is a better practice for carbon steerers than cutting a few millimeters below the stem. Have you seen examples of damaged caused by cutting below the stem?

Best option of all that you showed seems to be the aluminum tube bonded inside the carbon steerer, then a traditional metal star nut down in there. Those things are always trouble free. Adds some weight, sure, but that's a good use of that weight. A few extra grams at most. The aluminum tube will provide a really good footing for a star nut and will also support and greatly strengthen against any possible crushing from the stem. That should be the standard. I might source some aluminum tube of appropriate thickness and diameter and retrofit my bike with that, never have to worry about it again. Good layer of epoxy between to prevent galvanic corrosion.

Very informative. Thank you! Would you recommend tightening the top cap before tightening the stem bolts? I think you must, to ensure proper compression of the stem against the fork. But Specialized says the opposite for the new Venge.

glad I ride a Specialized

Thanks for naming and shaming Raoul. Really interesting content this.

i never notice carbon forl would expand that much. Planning to remove expander for weight saving like Canyon do, nowi have to reconsidering.

I still use several youngtimers with 1‘ steerer tube.Unfortunately for 1‘ there are not many stems that can handle carbon steerer tubes due to sharp edges. So what i did was using a shim between tube and stem,what really works well. In 1‘ you can’t get plugs anymore,and the old ones like you showed are all too short.... After how many km/ time intervals should i check on the stem/fork system?!

Great video Raoul. I have the 4th one that you showed inside my fork. Don't you think this type ruins the internal part of the fork? When it expands inside it clings with the checkering and when you disassembly it the inside of the fork is no more flat but you clearly see and feel with the fingers the checkering marks. Is all this safe for the fork in your opinion?

Thanks Raoul, this came up as a recommended video and coincidentally it's something I'm dealing with on a Ritchey Break-Away. The standard compression plug is Ritchey (unremarkably) and slips at the recommended torques for it and the stem. I can over-torque the plug against the stem, but I'm not comfortable with that situation. A replacement brand was marginally too large for the steerer, but still very short. The steerer ID is around 23.7-23.9 mm as measured at various points both with a bore gauge and with a plug. The stem height is around 42 mm. I could machine up my own but it's a lot of dicking around for something that's available off tthe shelf quite cheaply. Can you recommend and particular plug for a steerer of that ID?

regarding your comment on the KP017 Cannondale (the first expander you threw away): The length must perfectly match that of the stem, with the lower part fixed under the lower stem screw. The thing is, even with a normal compression plug, if the upper part's diameter doesn't perfectly match the inner diameter of the steerer, you're going to have the same problem. Besides, researching a bit on the internet show very few people having problems with this specific part (KP017). Do you have any negative experience with this?

Would the placement of plug matter so much when we use it to only tighten the stem to bring the steerer up, to seat into the headtube bearings? Then we tighten them stem to lock it all in place. Also along this thinking, wouldn’t it be best to have the plug in the same area along the steerer tube the same as the stem?

When installing one of those expanders that have a unique vertical slot, is it better to put this slot at the screws side, opposite to the screws side, sideways, or this doesn't matter at all? As one of the tasks of the expander is to counteract the compression force of the stem, I would say that it is better to put it on the side opposite the screws one but I wonder if the expander doesn't play a role also in counteracting the forward bending forcethe fork steerer is subjected to when the body weight is placed on the handlebar, although this is already partially opposed by the spacers under the stem, and then in this case it would be better placing the slot sideways.

After that introduction, I think a series called "Throw It Away" would be really fun.

I have cracked a carbon seatpost and had to finish a ride standing up on the pedals with a floppy seat. Not great, but not life threatening. I heard a story a few years back of someone locally breaking a steerer and getting a broken neck out of the deal and some other broken bones.

I bought a 'PRO' compression plug - 50mm long 1-1/8 (PRHS0072 is the exact model). It says >Ø 23 mm for inner diameter.. the steerer on bike is 1-1/8 But the plug looks so thin. Maybe about 20mm diameter, when it's round. Only very small middle part of each of those 3 long thick side pieces is really in contact with the steerer wall, when expanded. Is that good enough? The inner diameter of steerer is 24mm. I'm actually not too worried, but.. I better ask.. I lack confidence. Maybe I got wrong plug? Or maybe there's a good reason why it's made so thin.. I guess it's best to insert it so, that one piece faces to front and other two to rear left and rear right... Because there's less material at front in stem clamp.. And other 2 help there at rear left/right against over tightening ? I chose it because I don't want to cut the steerer. The original plug wasn't also very bad, but after I lowered handlebar to max. It only supports upper part of the stem clamp. Making it difficult to get torque right on lower bolt of stem.. with a scale and regular hex key. So instead of torque wrench, which was more expensive, I got this plug.. And continue misusing the luggage scale that I already have.. :D

I absolutely agree with you about the steerer compresion plugs. What about handlebars at the stem clamp? Is the situation different than the steerer? It is not possible to support inside the handlebar.

Is it normal for fork steerer to chaf when installing a stem?

I have a video on my channel that looks at the Specialized compression plug in detail.

The steerer tube that expanded slightly so the spacer wouldn't slide over, once the torque was backed off and the spacer would slide freely would this fork still be safe to use?

What do you recommend for torque on the plug?

I had to cut off about 40mm of steerer on both my old Look HSC forks cause Look used to factory install a metal expander that eventually gives them cracks!!

Can i also use those plugs for mtb suspension fork? Hope to hear from you.

I’ve just bought a compression plug for my carbon fork. It’s 7cm long and goes way past the stem line. Hopefully that helps 👍👍

If a steerer diameter is expanded where the compression plug pushes against the inner wall as you demonstrated, but reverts back to its original diameter once the plug is removed, is the steerer damaged in any way? Even if it is safe, it seems the longer, less concentrated expander plugs may be better for the steerer?

The white frame in the back looks interesting. Is that a TT bike frame, like the Lotus bike?

have you seen Hope HB160 how it´s made videos?I think a frame is always overbuild but in the case of MTB carbon bars I´m very afraid to put one in my bike. What do you think about Hope bike?It looks good to me,no filler,exposed work,you can see the fibers...What is your opinion about it? Great video...I´m waiting you to cut and enduro Mtb bike or trail bike to see what is inside.

Thank you for this. Which expander plug do you recommend for a hi Mod fork then? Thanks.

What was the brand of that segmented steerer plug ?

Crazy hands

Can the compression plug itself be over-tightened and over-expand the tube? Also, have you ever come across a Specialized 'multi' stem, with the angled shims that go between the stem and the steerer? What do you think of them? Any compromises? Great video Raoul! I always look forward to your content. Literally cannot believe people would try to save weight in this area...

What’s is the recommended torque

In terms of weight, wouldn't it be best if the compression plug could use (carbon) spacers internally to move it to the exact height of the stem clamp? That way the expander plug could be minimal weight and still have full adjustability without needing to cut the steerer or use an overly long compression plug

What’s is the recommended torque?

So how much torque does these plugs should have ?

suggestion for compression plug for sterer 1 1/4 this is a canyon endurance model

3:58 I seriously cannot comprehend that people have dropping a few grams as being a higher priority than having a structurally sound steerer/stem interface...you could probably lose the same amount of grams by using that segmented cable housing from Jagwire or Nokon.

Is 5Nm typically the correct tension on a stem to steerer tube connection?

I have a question. Why carbon seatposts don't require a compression plug to withstand the clamping force?

What about the Cane Creek double star nut? Seems like it offers no support at all, thought it was designed that way, so maybe that's okay? Thankfully, this is installed on an aluminum alloy fork, so I'm don't think it needs any support. Thoughts? Also, is it true that the compression plug's main function is to allow pre-loading of the headset bearings, only during installation of the stem? If so, isn't there a better way to do this? What we need is a way to pre-load the bearings without getting in the way putting a "structural plug/sleeve" inside the fork tube, exactly at the stem location and with the precise diameter, so we can then tighten the stem clamp producing a more durable assembly. Hmmmm....

So, I have a couple of aftermarket carbon forks on road and gravel frames. The manufacturer calls for the cut to be 7-8mm above the stem and effectively leaving a 10mm chimney. Is there a reason for this? For compression plug placement more centered in the stem? It’s the only thing I can think of.

Which to tighten first, compression cap or stem bolts?

Could you list some specific fork compression plugs that you recommend?

if i keep the stem at the top is the factory plug safe enough?

Given thevery different Youngs moduli of carbon composite and say aluminium, is a metal plug going to do much to help? Wouldn't a thick carbon inner plug be safer?

Just a question, if you could please answer about a different design you didn't mention? LOOK have a aerostem or c stem and doesn't use a plug, it has a locking ring at the bottom with a 16mm spacer, a rubber boot is then fitted, then the stem fits over the top. It uses a internal clamping arrangement, which is external to the fork tube. The stem can the adjusted to height as it has a tilt function. My question is, how does LOOK get away without supporting the centre? Cheers Raoul.

It looks to me as if the compression/expander thingy is more dangerous than a stem clamp without any burrs, as a tube is more susceptible to expansion than compression? And it's very clear that all breaks happen outside the clamping area which is quite strong even if it is slightly damaged, so should an expander actually extend below the stem clamp? Is there any indication that these breaks, as one would suspect, preferably happen to big sprinter guys?

Do you need to put in a compression plug if you are using 100% chromoly forks and steerer tube? Or do you just need a star nut?

Watch at 1.25x speed!

Thanks, can you share any of the product names?

Specialized, is it possible to install 2 plugs??

follow the torque limits

Well put & yet can you believe the brand Canyon don't even use an expander/compression plug on their carbon bikes...what a joke.

If this is so critical how does one perform a bike fit by moving the spacers and stem around the steerer? Would you cut your steerer each time you want to try a new position to get that support from the expander plug?.. I have seen so many bikes where riders just could not be bothered by cutting their steerer and they have a huge pile of spacers at the top and stem slammed all the way at the bottom...

I am sure this has been covered somewhere on this channel but why is carbon so weak in compression vs metal?

So I presume the Carbon-Ti expanders are pretty useless? Got a new Bianchi which came with this expander...

Is it possible to use an extra long compression plug when you cut off your steering tube too short?. Or do I need to order a new fork?.

What happens when the bottom cone of a compression plug is seized with the screw and can't be removed anymore? Pulling it out as gently as possible would cause severe damage to the steerer?

So once the stem is installed, is it safe to remove the plug? Lots of people do that to save weight.

This seems to miss the point of the compression plug. The first red flag is that we have to assume that company after company is failing which doesn't make sense from a warranty/injury perspective. Obviously we haven't seen any of this damage/injury in the cycling community. The stems we use in cycling do an excellent job of dispersing forces along a wide area along the steerer tube. An impact on one area of the tube (like a head-on collision) isn't felt in just the one face area of the steerer (closest to impact) because the stem is clamped around the entire tube so it's dispersing this pressure and would need enough force to crack the entire section of the fork around the stem (significantly more force than what we see in 99% of collisions). Imagine trying to punch through a glass cylinder with a thin wooden wall immediately in front of it; you may easily be able to push through that wall and damage the glass. Now wrap the wall around the glass and tighten it to it so there's no void (like a stem). Now you have to have enough force to sheer the glass under the wall to break it; it is SIGNIFICANTLY more difficult. A compression plug doesn't do anything to help in saving the tube either since it's not adding to the dispersion of the forces (the stem is obviously tight evenly throughout the steerer these days). This shows a fundamental misunderstanding of the compression plug. The second I call out multiple manufacturers for an otherwise obvious flaw is the second I should be questioning my understanding of the concept. Imagine the amount of crashes we'd be seeing if plugs had to keep the stem on!

That one you said was good is what you get with Chinese stuff,that's ironic with people saying the China stuff is rubbish

Not all Giant overdrives are like 5:40 Most latest overdrives are the good type @ 3:40

The reason the giant one is thinner in the middle is so the plug opens it up... If it was the same diameter all the way it wouldnt work woul it..

Is that a “superbike” frame in the background?

No compression plug on my Canyon, it's hollow, it uses some weird solution from Acros (Ai-70F).

If the compression plug is supposed to counter the clamping effect of the stem, then why aren't there variable length compression plugs for when folks want to drop their stem but not chop the steerer column?

I got tge cannondale compression plug on my caad12, and now i am somehow concerned about my safety...

What about Canyons Road Bikes? They don't have compression plug at all.

Wouldn't the larger expander bolts negate a significant amount of the weight savings from the carbon fork? Carbon forks are usually only 300 grams lighter than a good alloy fork.