In a recent video I remarked on how I thought the steerer compression plug should not be part of the structural system of the steerer. This may have been a little confusing, so I thought it would be worth clarifying what I meant.
I don't know why this video needed to be made, it was perfectly clear to me the first time you addressed this. Having said that, still love your videos. Keep em coming!
I thought you were pretty clear the first time I guess I'm still old school and like a threaded Chris king headset and cinelli quill stem from my hard core riding days. Never had any issues with either or the dura ace 7400 square taper bottom bracket.
I thought you were crystal clear during the first video myself. Made me think I should check (Didn't yet but will) my 2007-8 LeMond Tourmalet that has a carbon seat post, front blades and I'm guessing steerer tube looking at the damaged example. I've hit some nasty holes in the road and never gave a thought to the inside when looking. Might have saved me Mr. Wildberry, thanks and be well.
Easton's internally threaded carbon steerer was a really great solution. A little alloy bung just threads in loosely to receive the top cap bolt. Definitely no steerer wall support going on there.
I bought two compression plugs, and modified one, whilst employing a longer cap screw, to double the length of the compression plug. I did it to increase its resistance to being pulled out. We should talk in person again, my friend. I used to enjoy seeing you in west county cafes and talking about the titanium bikes we rode. I have some good ideas to share. DM me!
I had a similar issue on my old Specialized Tarmac (cracked steerer, possibly due to the compression plug). Because I'm hefty, I replaced the fork with a carbon fork with an aluminum steerer. Star fangled nut for the win.
Hi Henry, I enjoyed the video and have taken your advice. I am looking at upgrading my road bike with a new stem and fork as well as new running gear (going from a ye olde 8 speed set up to a 10 speed set up with a big cassette at the back and smaller chain rings at the front). You gave me food for thought on the carbon fork I was thinking of getting. I was looking at getting a unbranded Chinese carbon fiber fork for the upgrade. This would be cheaper than getting a surly alloy fork and make the bike a bit lighter. It would also make the bike look a bit better (yeah pretty shallow I know). Your videos made me think about the quality of the components and the risk of failure. I live in the Australian Capital Territory in Australia. Here in the Australia we have had 2 deaths from fork failure one case was a guy who had replaced the fork he had on his road bike and had gone over a pothole in the road which destroyed his front wheel. He replaced the wheel and inspected the fork and found no damage to the fork but the fork failed some months later and he died of head injuries. While I won't rule out a carbon fiber fork, I will be insisting on a good quality steerer. I am now more inclined to go for a carbon fork with an alloy steerer tube or a full alloy fork.
I'm very sorry to hear about the cyclist's who have crashed and died. Not knowing all the details of the crash or potential causes, the best recommendation I have heard is to replace the fork after any crash, regardless of whether it looks okay. At the very least a NDT is warranted to rule out any hidden delamination between the layers of the carbon. It's the price you have to pay to ride the lightweight stuff and to keep yourself safe. Aluminum is not free of problems. It has a fatigue life and it is prone to corrosion. It is cheaper, so the price to replace a damaged or high mileage fork is easier on the wallet. Carbon fiber forks are generally safe and have served many people very well, including myself. Carbon has a very high strength, it is corrosion resistant, can be bonded to metals like titanium and aluminum (for added reinforcement), has a decent fatigue life, but has a low impact resistance. I tend to be on the conservative side, admittedly, and find myself torn between the lightweight and stiffness with the practicality of other more durable materials like steel. I have had many good miles on this fork and other full carbon forks without any issues, but question whether the weight savings is worth it. However, I think keeping a regular eye on the steerer and not over tightening the stem bolts will help, as well as keeping the headset preloaded, and checked often. All the best!
I understood the first video. The reason for the long compression plug is to spread the load over a larger area. A star fangled nut would be a disaster on a carbon steer tube. I consider a steel or aluminum steer tube safer as you might get more warning before it fails. Unfortunately the junction between aluminum and carbon can delaminate due to different expansion rates. Make my fork all steel threadless ideally. Threaded headsets should go the way of cottered cranks!
Agreed, a star nut wouldn't be a good idea inside a carbon steerer. My point is very simple. Why is there a large load on the expander plug? Did someone over tighten it? All it needs to do is grip the inside of the steerer enough to preload the headset bearings, which isn't a large load either. In theory, once the bearings are preloaded and the stem clamp torqued, the expander plug could be removed. Besides, it doesn't take much surface area to safely distribute expander plug loads without cutting a groove into the steerer. There seems to be a contingent who think the expander plug needs to extend below the line of the stem in order to prevent the stem from crushing the steerer. I think there is something very wrong in the design of a steerer that cracks or breaks under normal riding conditions without an extra long expander plug. I have no issue with threaded headsets. The steerer is not loaded in the same way as a threadless steerer. The stem loads are passed to the inside of the steerer through the quill. There are no bending moments acting on the threaded part of the steerer.
None of my bikes have that compression plug. Most have a quill stem. In your last video you mentioned trail and toe overlap. I'm a lot confused about trail, fork offset, etc. I have a vintage Trek 700 with major toe overlap that I didnt really notice until it almost crashed me. Now I'm beginning to look at geometry numbers.
Forks with larger fork rake (offset) have lower trail. The trail affects how stable the bike will feel. A bike with a higher fork offset will tend to have less toe-overlap, but can feel less stable. It's a trade off. Most road racing and track bikes have lots of toe overlap, but they typically don't need to steer the bike around sharp corners. Mountain bikes and gravel bikes want less or no toe overlap because they are often ridden in technical conditions with lots of steering. The ways to decrease toe overlap are either longer front-center (e.g longer top tube), slacker head tube angle (moves the front tire further forward), increase fork rake, or decrease wheel diameter. Usually, the frame designer will consider all these factors and choose each one based on the frame, wheel size, and intended riding style. I hope that helps.
Modern BMX forks have one piece chromoly steerer tubes with a simple welded in nut. Not sure why road/gravel bikes would need anything more complicated than that. Forks seem like the most risky place on a bike to try to save weight.
I hear ya! Ive always used steel or alloy steerers and I can get lots of this overpriced plastic junk at cost! I know exactly why people buy such junk. They're either blinded by marketing BS, they're lazy and fat or they believe a bike can make them fitter or give them better skills. The 'suckers born every minute'. Lightweight junk might, just maybe, be ok for race day for really skinny riders who know how to actually ride smoothly. Carbon is actually a very strong material, but very few cyclists can afford the level of high quality required , nor will manufacturers sacrifice their profits to build it. I can see proof of that in the shop every day I'm at work! I know. Ive helped build aerospace components and Ive wrenched on bikes for 50 years. Nobody's fooling me
Backing up your thoughts is the compression plug supplied with Enve carbon forks. It’s quite short. Their steerer tube is all carbon, so I would hope their design is based on no reinforcement from the plug!
The longer plug came with the unknown brand fork with the bird logo on the side. The shorter plug came with the Enve. I'm assuming that means the Enve steerer can handle the forces without counting on a plug. I did measure the thicknesses of both steerers using my vernier calipers and they are same.
It may not be fair or 'right', much less moral. But it IS reality. Learn the truth for yourself. Ignore marketing BS. That's nothing but propaganda or brainwashing. It exists to separate you from your money. When we spend money, that is each of our decisions and responsibility. Once we spend it, it's no longer ours... ALL the evidence has existed for decades. The larger bike industry is concerned with shareholder profit. Consumer safety and satisfaction takes a seat in the nosebleed section. QC issues dont just effect carbon forks or high end bicycles. They effect all bikes especially at entry levels which are sold in vastly larger numbers. Quality control is a dirty little secret in the bike biz. Anybody can slap a sticker on a bike. I loved sticker bombing my bikes as a kid!!
@@trajtemberg You missed my point. These 'safety issues' have been going on for a long time now. Its well documented if folks would just look and ignore marketing bs. Look at Specialized' actions right now. Guess what ? More steerer and expander issues! They know what they can get away with. The suckers born every minute keep buying all this garbage.
Actually they are rigjt when they say that. Its easier to produce longer sompression plug than to push the bike sector to create stronger steerer tubes or to go back to magnesium tubes with star nuts for every bike type.
If that was true, the manufacturer of the fork would need to provide the appropriately sized compression plug to ensure the steerer is properly reinforced. That's not what is currently happening. Some people are swapping out their shorter compression plugs, for longer ones, hoping it will help to make the fork stronger. Do you see the multitude of problems here? What if someone needs to get a new compression plug and buys one from the local bike shop. Could you imagine the risk?
The word you're looking for is "cheap". Maybe you could find a piece of steel pipe to fit in there and reinforce it. 🤣 Makes me love quill stems even more.
Carbon Fiber is very strong but its impact strength is less and brittleness greater than many metals, not making it a great material to remain under compression, IMHO, esp. when hollow.
For racing maybe that's acceptable. But for daily ridden bikes, gravel, bikepacking and touring bikes that get used hard, abused and truly relied upon for real life? I'm not so sure. I see rich guys come in my shop and buy $10k super bikes to commute 10 miles. We'll gladly make the sale. When somebody hands over money, that's their decision.
If you think that's bad, look at the failures of integrated stem and hidden cable systems on Specialized SR7s. Recently recalled. I'd say this has gone too far, all this testing on the public. The problem is probably solvable but why would a company risk having one fail at a major race with a star athlete on international TV like Canyon Aeroroad? We know they can't always make a round hole and don't care about safety. They've got people to deal with that. Deny, delay, defend.
@@davidburgess741 Examples of poor engineering, bad quality, recalls and a lack of common sense are nothing new. It's all been going on for well over a decade. There is a solution. But this is an endless vicious circle. It will never stop until people stop buying garbage and wise up. The consumers who buy into marketing BS have the problems. The people who believe producers of proven failure buy the problems! Its pretty simple. . There's this amazing trait called 'thinking for oneself', learning truth for oneself. Critical thinking. I think lots of colleges and universities have banned that. I never even got a degree. I just got my hands dirty, worked hard and read a lot.
@@rollinrat4850 carbon can be made safe to use on a bike, but at that point you are reaching weights that you might just as well get the cromoly and be done with it.
@@Exgrmbl Carbon rims practically designed for common usages arent much lighter than aluminum rims. They are a bit stiffer, but that only makes much difference under hard accelerations. Either that AND, OR manufacturing quality would need to improve in a drastic manner. High quality costs extra. There's a real reason why bikes started to be primarily be manufactured in Asia since the '90s. Nevertheless, the consumer WILL ALWAYS PAY, one way or another. Consumers need to wake up, think for themselves and ignore marketing BS. Spending more on 'high end' products doesn't even assure quality any longer. That's a misconception. IT IS consumer's own money they are spending. Once it's spent, the money belongs to somebody else. That's their decision and their responsibility.
Thanks for the clarifying. It would have been better to say, "the compression plug is pushing outward on the inside of the steerer." Just like air in an inflated tire.
@@Henrywildeberry Totally got what you tried to get across, and in fact the steerer is compressed - just not outward. It's just that one word that threw it off, but I understand it's unscripted and some extra words sneak in when you freestyle it. And the compression plug might be inaptly named... should just call it an expander plug as a standard.
@@orsations The steerer compression plug does seem like a misnomer. Expander plug is the least ambiguous. I'll try and remember to use that from now on. I'm glad I get a little leeway for my freestyle. I just don't want to take the time to write a script or have to read off a teleprompter.
Learn the truth of carbon manufacturing in the larger bike industry. There's plenty of truth and facts out there. Learn about the waste and filth that IS carbon manufacturing. Is this really a 'green sport' ? Understand the serious joke that is consumer safety and consumer satisfaction in the larger bike biz. Its all your own money you're spending. DIY the most you possibly can. KNOW the sources of what your life relies upon Very few know about carbon quality in bicycles. You just trust someone else. You can only truly 'see it' when you cut it up. Believe it or not, again, it's your money. I'm a retired mechanical inspector. I helped build stuff from composites. Now I wrench in a high end bike shop. Nobody is fooling me. Take a look at Specialized' actions right now!
It's ok to have opinion, but you are wrong..expander is there to provide stability and should be ideally long as your stem + space length ...9-10 cm ..there is no carbon fork which can last long without expander..it is designed to work together
Is this your opinion or do you design forks for a living? The expansion plug does not reinforce nor should it reinforce the steerer tube for a number of reasons. First, it is not bonded inside the tube, it’s a friction fit. In order for the tube to transfer bending stresses it must be bonded internally. The same can be said for the compressive hoop stresses generated by the stem’s clamping forces which are very small and insignificant in comparison. Second, the materials have different elastic properties and therefore do not share the loads equally. The stiffer element will carry all the load until it fails. Furthermore, once the first material fails the friction fit will be lost anyhow. This is all basic mechanics of materials behavior. Third, fork manufacturers do not necessarily require their own compression plug design, meaning you can buy aftermarket compression plugs of different lengths and styles and mix and match them with your fork. That would never happen if the fork manufacturer purposefully designed the compression plug for a specific reinforcement task of a fork steerer. Think about it. Forth, most of the compression plugs are too short to reach the highest stress point which occurs below where the stem clamps onto the steerer. Draw a bending moment diagram with a rider hitting a large pothole. With the compression plug on the inside of the steerer, at the point of lowest stress, it doesn’t provide any reinforcement. After you draw the moment diagram then draw a cross section of the steerer with a plug inserted and draw all of the principal loads and you will see the plug is at the lowest stress point. If the carbon steerer is too weak to support the loads it should be redesigned with a larger diameter, a thicker cross section, or made out of a material with better mechanical properties. Yes, this my opinion. I'm not here to give advice, these are just my observations. All the best.
