Specialized Tarmac sl7 recall | how safe are any carbon steerers | 3D animation | Bikotic

For this video I have created a 3D Animation of the headset and steerer tube of a Specialized Tarmac SL7 to look at the new parts being fitted after Specialized issued a recall of the Tarmac SL7. I also ask the question are any carbon steerer tubes safe to use in the long run?

[@inspicues3041]

Can we just appreciate the amount of research and effort to make this 3d diagram? I am impressed

[@Hambini]

A+ for the graphics. Blows my powerpoint into the weeds.

[@bikotic]

Thanks!

[@amarmangaonkar7682]

Damn I feel soo bad for you, cuz I know how long it takes for 3d renders and sketching. Really great job

[@alen-commentnazi8774]

Yeahhhhh shts tuff

[@ronradmer3573]

YES... Thank you for spending all this time to put this together. I am not an engineer by any means, and parts of this were a little over my head. But great job and we really appreciate you doing this.

[@SenorGonzo]

Beautiful graphics, amazingly done! I guess I dont need to worry about my sprinting, putting out 10’s of watts.

[@valiantabello]

Stop bragging

[@Rob-fx5yn]

From a mechanic, that's a great explanation well done!

[@LuescherTeknik]

Great video on this safety critical topic. Excellent presentation and rendering.

[@bikotic]

Thanks Luescher, appreciate that. Many of your videos were inspiration!

[@TheCharnwoodCyclist]

Good video. The expander is there to protect against the stem clamping forces, nothing underneath should be designed to allow damage to the fork, yet Specialized have managed it. The new fix is as I understand it has a longer plug yet the lower half of that plug isn’t under compression, it is just there to stop you having a potentially life threatening crash. The new ring insert appears to be there to stop the metal collar from cutting the steerer. I’ve got two carbon steerer bikes, both have long plugs fitted by myself for safety, never had any issues as they are designed properly, I took a friends Bianchi apart a while back and was shocked to find a 10mm deep compression nut and clear micro cracks in the carbon steerer. We need to go back to simple, safe designs and companies like Specialized seriously need to change their ideas, they knew about this long before the issue was announced and had time to provide updated parts, even worse it’s suggested the pro riders had alu sleeves inside their forks. If that’s true it tells you all you need to know about Specialized as a company.

[@bjsr126]

If you go look up a Tarmac SL7 build for Peter Sagan at the start of the TDF, which was in what? May? The mechanic was clearly seen putting the Alu sleeve in them. Myself and many others were wondering what it was in the comments

[@Xclnt507]

​@@bjsr126where can I find that alu sleeve?

[@bnzboy]

I've already seen the aethos frame cracked via online forum and two of them were ridden by some light female riders. These lightweight trend seems to be an experiment by the manufacturer and the purchaser is the guineapig.

[@lukewalker1051]

I am an engineer and so will comment. Brilliant video Bikotic. A few words. First, let me say, for a non engineer you have a really great grasp of the situation. So what's up? In engineering parlance, the core of the designs of many machines and assemblies like this, is what is called a stack up event. Maybe you have heard of the term perfect storm when a confluence of factors comes together to create a catastrophe. What we have here. How many out of 100 SL7 bikes sold will fail? 1? 5? 0.1? Not many. But....way too many statistically for people who buy this bike as many have heard of this issue that are into racing bikes. Recall campaigns are expensive for any company. But...but....nothing will bankrupt a company faster than hurting or killing people if determined their product left the manufacturing floor with a defective design. What is a bad design? A bad design does not account for manufacturing variation and variation in environmental conditions. This is for example why bike manufacturers place a weight limit on their carbon bikes. So, how did this design get out? Why was it released? Mostly greed and lack of due diligence. That said, engineering is very difficult outside of controlled conditions if the objective is absolute highest performance. No different than designing a race engine for a race car. Race engines fail at a higher rate than production engines but a production engine could never do what a race engine can. There is a document in engineering called a DFMEA which is a critique and rating of failure modes. A steerer snapping which is nothing new with carbon bikes is near the top of the list. By definition, this is a negligent design. Why did it come about? For internal cable routing mostly. But, the design does not have to be configured like this. Why did it fail? A lot of reasons, each a small contributor to a bigger problem. What does the perfect storm consist of: 1. Rider weight and strength: a 1500w, 90Kg rider will fail the steerer with much higher probability than a 300w senior citizen 2. Bad roads. Repeated riding on bad roads can put a notch in the carbon...especially with loose headset. Carbon as strong as it is, does not like point loading 3. Loose headset. You illustrated why. 4. Tolerance stack up of the parts. This is key. Specialized missed the proper stack up to ensure that retainer would not act as a knife edge. 5. Bike weight. The SL7 is the amalgam of Venge and Tarmac. A more slippery Tarmac with Venge frame sections. Aero bikes are heavy due to adequate moment of inertia in bending aka under rider acceleration and high watts imparted to the pedals. This means, corners are cut to keep the weight down on a bike like this. Many have seen the flexible downtube videos of the SL7. This is because in the section strength of the downtube, the wall thickness can be dramatically thinned out but the very deep wall section vertically of the downtube compensates for the lack of width. The downtube is basically an airplane wing turned on its edge. This is why aero bikes are heavier than more conventional tube bikes which are stronger laterally like the outgoing Tarmac SL6 and of course weight is the elephant in the room with disc brakes in particular and so strength is compromised where it can be on other areas of the bike. I can go on and on about design tradeoffs but above are some of the highlights. So lets review who will break this bike? Most likely, an elite rider with huge power who doesn't adjust his headset precisely, who lost the tolerance lottery from Specialized and has a slightly undersized collar ring, maybe the carbon lay up could be better, he rides a lot of rough roads and prefers a wider handlebar for leverage...perfect storm and snap. Who won't break it? A 100 lb girl who doesn't race, rides smooth roads and has a good mechanic who always checks the headset and even periodically removes the steerer for inspection and regrease the bearings. Hers is never going to break. The increased length expander plug that Specialized released as a running change....btw, not their first rodeo on this and they have released a longer expansion plug on previous gen bikes prior to advent of internally routed cables...this longer expander plug adds weight. That is why it wasn't in the original design of the SL7. It also likely costs 20 cents more per bike to make due to more material and machining. Weight and cost. What to do? Personally, with the track record of the bike, I would never buy one. With the change and proper maintenance, periodic steerer inspection etc, should it be safe for the average person? Absolutely. A last note. The SL7 is Specialized flagship race bike. A guy like me looks at this design and shakes his head. This should have never happened. Shame on Specialized for this design. The ring inset into the top of the headset is a knife edge and a stress riser. We don't know the condition of the bike that broke in the video, but I am sure there are many elements of a perfect storm. It may not have had the small ring to shield the retainer even installed...or even 'any' expansion pl;ug that wasn't detected in the video as mentioned...because none were shown. We don't know. Me personally? I don't like the SL7 enough to buy one and to me, the SL7 is way too expensive for what you get anyway. Lastly, a question please Bikotic. What software did you use for your modeling of parts you show in your video? Can this software be used on a home PC or laptop? I presume it isn't freeware and you paid for it. Thank you for the excellent video. Ride safe everybody and never a bad idea to remove your fork from your carbon steerer once in a while and check for any indentations. People largely never do this due to inconvenience, but with all bikes with carbon steerer tube there are compelling reasons to remove the fork once in a while, check the bearings, clean and regrease and check the steerer tube for denting/degradation. PS. Years ago when George Hincapie's steerer broke in the Paris Roubaix race which is grueling on any bike, initial reaction was to demonize Trek for this failure. We all know George is a large and powerful rider and the cobbles are a daunting challenge to the structural integrity of any bike. Upon closer examination of the facts it was learned why big George's steerer really broke. He was involved in a crash earlier in the race which created microtearing of the carbon fibers within the steerer. Greatest stress is always at the top of the headtube and just beneath the stem clamp. Repeated vibration later in the race combined with George's considerable force on the handlebar created ultimate failure. Bikes may not fail upon an initial crash but can be weakened. Carbon layups can delaminate on some level due to excessive force/deflection. A little tech is...carbon lay ups are much stronger in shear than they are in bending. We don't know the history of each bike that breaks including the SL7 bike in the video that went down which was hard to watch.

[@bikotic]

Thanks Luke, an interesting read. I use Blender 3D, its a free open source fantastic piece of software

[@sebbelito2975]

Really great reply, enjoyed reading it from an engineers perspective on the SL7. thanks for sharing :) The compression ring itself, would you say it is safe design wise with the big holes on the side? The internal ring is so thing that it really doesn't make a difference in strength... It is probably just there to prevent cables touching the steerer and lack of chamfer. Speaking of which, could they just not use the same compression ring and machine chamfer around the edges? File away some material to make it more smooth.

[@sylvainmichaud2262]

The problem is threefold. 1- Fragile carbon steerer tube. 2- Integrated cables and hoses that may rub or impead bearing movements. 3- Integrated cables and hoses that makes maintenance and inspection long, costly and complicated which may lead to negligence from certain owners. Basically, a catastrophe in the making. But the worst part is that many bike shops have poorly trained sometimes inexperienced mechanics without the ability to scan the carbon parts.

[@povertyspec9651]

Too short of a compression plug. Plastic spacers between bottom of stem and top of headset.

[@sylvainmichaud2262]

@@povertyspec9651 Why do you need a longer compression plug ? See#1 Fragile carbon steerer tube. Why do you put plastic instead of metal spacers ? See #2 and 3 cables and hoses rubbing and their long term durability (maintenance). Don't confuse symptoms with causes.

[@andrewbobro3374]

As an engineer myself, you did a good job here.

[@peterwinkler8382]

You're really good on the 3D imaging. Thank you for this video. I am a titanium guy, but I was almost ready to buy an almost new ti bike with a carbon steerer. I'm 5'8", 198 mostly muscular. I just don't feel safe unless the steerer is alloy. I have had my fork/ steerer tube (alloy) for 16 year, and it's as good as new.

[@SM-67]

Great work, your graphics are brilliant 👍

[@dwaynepedals]

Great video! I've recently had this happen. I learned that the compression plugs need to be longer. It's important to measure at the top of the stem to the top headtube bearing and ensure that the compression plug passes that top bearing. In some cases you may need a 90-100mm compression plug depending on spaces. This will strengthen the fork steerer when tightened at the stem.

[@guillmunoz7474]

Thank you so much for your invaluable research on a hidden danger. I have a Specialized Paris Roubaix SL3 and I will take the fork assembly apart for inspection.

[@tombola4046]

Brilliant video and very informative. Lack of information by the heavily sponsored cycling media such as GCN which are terrified to say anything negative about a major player such as Specialized. I’m sure SL7 will win countless awards 🙄

[@chrisbinch800]

An excellent visual representation of what durianrider has been highlighting for a long time.

[@bikotic]

that's a fair comment.

[@JanHolgerOlof]

Brilliant video. The 3D rendering makes everything so much more comprehensible. Thanks for putting the effort into this! I ordered a longer compression plug for my integrated setup and I kinda new why it would be safer but I had trouble really visualizing it. This helped a ton

[@EditioCastigata]

I'm an engineer, and as far as I can see you've identified the issue. So, the longer expander is for damage mitigation. The metal collar 1:40 is the actual workaround: It should be wider (taller) than the "compression ring" and made immovable by a retaining compound (glue) at the place. Bonding a metal tube inside the steerer rube, as suggested by you, won't prevent that abrasion on the outside. -- For example, Time has on some bikes that collar already bonded (Time Scylon), as alternative Time (ADHX) and Deda (Superbox) ship with wide plastic "compression rings" that'll also do the trick.

[@BRo-it1jh]

Wow, you put a lot of effort in this video. Thank you so much!

[@princeg973]

Damn you've really done a great job with the 3d render. Hight quality as always, love that :^)

[@tomcosgrove7240]

A brilliant description and illustration of how headsets work - the 3D modelling is amazing!

[@ricecrash5225]

Mate this is brilliant. The modelling was superb. Well done.

[@shikharkalsi9692]

This is fantastic… so thorough.. well researched and presented, thank you for your efforts.

[@superpedro4691]

Perfect 3D , Graphics and comments

[@truthseeker8483]

Thankyou for making such an informative video. As an engineer I have to say the Specialized compression plug is a LOT better than many I have seen. I don't think I would ride a carbon fork without a long long compression plug that goes well below the upper bearing. I like your idea of an alloy tube bonded inside the carbon steerer. I have a 23 year old steel frame road bike I was thinking of updating to carbon forks but now after seeing your video I think I might stick with cromo forks.🙂

[@nuttynut722]

you are officially putting more effort into this than spesh itself!!

[@treyquattro]

very impressive work on the 3D modeling! Great video.

[@sascha1778]

This video is an incredible piece of work. Well done!

[@bigwave_dave8468]

Beautiful rendering and modeling! Here's a data point: I just got a specialized Aethos (not Tarmac). Specialized is very clear in the instruction manual that you should not add any spacer stack greater than 5mm above the stem except for fitting -- I gather it's because of the ideas you discussed. Further, they also specify that you must use the spacers they provide below the stem -- These spacers are not solid, but rather, oversized wrt the steerer tube and have some nubs on the ID so they are centered around the steerer tube and provide an easily sliding fit.

[@AndiamoEndurance]

Great video, love the detail and the animations! I have a Cervélo Cal-5 of which the headset failed on me after only 200km... It didn't crack and I was very on the safe side just shortening the ride and getting home... The glued-in insert for the headset had come loose and was coming upwards whilst riding, so that possible 'solution' of a glued metal piece only makes sense if they actually have a proper bonding in the first place... Being (not) glued in, it actually made servicing my bicycle on the fly impossible, which might have been possible with an expander plug that wasn't tightened properly.

[@kuanhau4323]

Did Giant see this coming and decided not to go with the integrated cable routing on the tcr?

[@XinneH]

thank you so much for this video! It solved an age old question for me.

[@duffyrides]

Wow. Amazing work you have done here with the explanation of how this all works. Good stuff !

[@road-racing.plofficialchan393]

Great job and very reasonable approach

[@darnellumagat3915]

This was well put together.

[@MattRose30000]

It's certainly adviced to disassemble and look at your carbon steerer tube from time to time... Regarding the high stack above the stem, it might either be that the person isn't able to cut the steerer tube to size after they settled for a more aggressive position, or they have a new bike and don't want to cut too low before they had a bike fit.

[@jonoharper4729]

I think that UCI should have specific regulations regarding the steering tube, specifically that it should be steel, specify type of steel and tube minimum thickness. This being a health and safety issue, the penalty of a few extra grams for the steel tube is well worth it, and gives the rider "peace of mind" that they won't experience a catastrophic failure.

[@andrewbirchall6469]

It is my belief that the industry as a whole needs actual law abiding regulations, these bikes are not being ridden by pro cyclists just the everyday cyclists, there should be regulations protecting them from this type of safety issues

[@seanbailey8545]

Sadly most of these frames/forks are just branded by big companies and are designed by Taiwan/Chinese designers. And the big bike makers just slap a sticker on it.

[@truthseeker8483]

@@seanbailey8545 Wongy Ching tech

[@durianriders]

Great 3D explanation! Correct that is the new compression ring that was shipped on SL7 since december 2020. That is how long they knew there was a problem...took them 10 months before the recall...and STILL IMO it isnt safe and needs to be inspected every few hundred km. The split ring shim would have flung out in the crash. Would not be possible to ride the SL7 with no shim as the headset would be SO loose and KNOCKY that even a total noob keto barrister on 500mg of modafinil for breakfast would notice something feels wrong. I think most SL7 owners will be fine as lets be honest, most people who spend that much on a bike dont ride it much. That said most S-Works owners are TERRIBLE at bike maintenance and wont notices a slightly loose headset with some nano play in it.

[@bikotic]

Thanks!

[@salvatoreleccese9720]

Jesus man i just spit out my lunch lololol damn u make me laugh bro😅

[@johnnyk6906]

excellent 3D description. I was in a process of upgrading my SL6 to SL7 when I heard about the recall. I am guess Specialized being largest road bike seller, they went the extra miles to make the necessary improvement but looks like it can happen to any carbon bike from any makers. I am done with my roadie for the year but I will have to check top to bottom next spring before resume riding.

[@steffengroe2497]

Absolut brilliant. Thanks for your video! Starting my bachelor thesis in mechanical engineering on carbon fork design. Hope I'll help developing carbon forks some day.

[@bikotic]

Great, good luck!

[@Guoenyi]

Beautiful animation. I got a carbon bike repairer to chop my steerer to leave about 3mm above my stem. That way I can keep a 5mm spacer above the stem for preload. Compression plug is short like the pre-recall sl7 and manual does say it should extend throughout the stem clamp segment or I might die. While cutting I did get the carbon expert to inspect impression on the steerer by stem. It was always torqued by a torque wrench evenly. He said it is ok, carbon can be a bit squishy in certain direction. I think if there is an overwhelming force that is where it is gonna break. I wonder how many broke there due to accidental impact vs. normal use like Andre Grepel sprinting. It would still be worth it for bike makers to just reduce the inner diameter. Would help to reduce breakages at very little weight penalty and manufacturing hurdles. Specialized did two things to extend the plug length. 1. Make sure clamp section is absolutely reinforced from the inside no matter how many spacers are added. 2. In case the steerer still breaks, the handlebars remain over the head-tube so the rider can remain upright somewhat and hopefully come to safe stop before falling. I think the change is a good one.

[@mickwilson2170]

Love the graphics... really cool

[@miles4463]

Awesome video @Bikotic, really impressive visuals. A follow up video with anything additional you learn would be greatly appreciated. Let us know how your first steerer check on your bike goes!

[@AOL0321]

This is why I just canceled my Tarmac order, and ordered a Lynskey titanium Helix. No worries and a known delivery date!

[@TavisYeung]

Brilliant modelling!

[@bgorin]

Really interesting, thanks a lot!

[@prowrench7989]

Re: Cervelo failure... I have to wonder if galvanic corrosion played a roll in the failure. Since Cervelo use (non factory installed) bonded alloy sleeve in the steerer, that area is perfect storm for failure. The area around the failure point seems have the telltale white powdery residue of corrosion. We routinely see this area (internally & externally) chalked full of sweat & guck on bikes that only see the basics of maintenance. With the explosion of interactive trainer riding, we have seen a significant uptick in front end damage (Bars, stems, headsets, forks & even frames) from the corrosive effect of combining sweat, carbon fiber & alloy

[@nicholoza8533]

I'd love to see a video comparing Trek Emonda SLR6 eTap and Emonda SL7 as well as the Madone SLR6 eTap and SL7. The SLR6 is their highest grade carbon with Rival groupset and the SL7 is their medium grade carbon with new 12 speed Ultegra. P.S. great video, I just got my Tarmac SL7 expert warranty parts replacement so hopefully I'm safe!

[@patrickparisienne1917]

Great job on the modelling and explanation!

[@jazzfan7491]

Wow, great explanation

[@arienzoamadeus6675]

Great presentation , i understand fully now this design have a lot of problem

[@JamesPedals]

Very cleverly done. I got my Sl7 expander plug all sorted but didn't have an issue with mine

[@wbezerras]

Excellent video!! It is clearly food for thought, thanks!

[@samuelmundula2216]

I definitely pop my forks out and check them at least 2x a year ever since I snapped my ALU steerer pulling away from a green light. I also think more should be said about not putting a ton of spacers on top of the steerer, I did that for a couple years and the LBS think that's what caused the stress to snap the alu steerer - I was never told by the manufacturer or a bike shop to not run the spacers on top, and I wanted to save the $30 on cutting the tube so I didn't do it.

[@Scoob99192]

Thanks for sharing this. Off to contact Specialized.

[@jamesbull9879]

Very I formative! Excellent work!

[@robcalkelme]

Wow ! Tony Stark would be proud 🤗 amazing graphics and brilliant explanation! Truly a specialized clip 😜

[@Perforator2000]

I have a new Cannondale CAAD Optimo 1 that started making a ticking sound from the top of the headset recently. When I put a lot of power through the bike, pushing and pulling on the handlebar causes it. It's like a random, infrequent single tick every five or ten pumps on the pedals. On the last ride, I figured out that the headset has actually loosened a significant amount, with visible play if I rock the bike back and forth. I've stopped riding it until I can take it back to the shop it was delivered through. I very much hope the steerer hasn't cracked and that they can simply tighten it.

[@povertyspec9651]

The spacers between the bottom of the stem and top of headset need to be alloy instead of plastic, with some compression force added by the stem cap added before the stem is tightened to the fork, to transmit loads.

[@JibbaJabber]

Well done. Excellent diagrams. Definite food for thought. Everyone should be routinely checking their steerer - or get the lbs to do it.

[@mataman1]

There's one problem with new longer extender plug. Bottom part isn't wide enough to do any strengthning of steerer tube.

[@kargi42]

With the extended plug at least when steerer snaps you don't go face first down but just go down.

[@TheCharnwoodCyclist]

That’s right, I think it’s designed to try and keep the two parts together for longer, to stop you having a fatal accident.

[@brotherfranciz]

@@TheCharnwoodCyclist How half-arsed is that? You resolve the problem by... not really resolving the problem?

[@TheCharnwoodCyclist]

@@brotherfranciz I imagine it was the cheapest solution that satisfied the legal team that they had “done enough” should accidents happen. I wouldn’t ride one of these!

[@kuanhau4323]

I think the answer is to have embedded stress gauges inside the steerer tube. Above a certain amount of deflection should be notified. Since there are cables accessing the steerer directly why not allow some cables to connect to the strain gauges. This would provide important feedback to manufacturers which is held by a safety union or collective whose sole aim is safety, not profit. This kite mark would be important. Please speak to Peak Torque about this idea for a KZbin collaboration. Where he can provide the engineering insight and you can provide the visuals

[@Dave-jg7ep]

excellent analysis imo

[@SenorGonzo]

Do you watch the channel “Peak Torque”? I think he did some video’s related to this topic. And he is an engineer. But not as gifted in the art department.

[@elchram]

Please do a collab with pt and hambini 🤙

[@terryvoice3908]

I was wondering about several Canyon bikes as they do not have the expander plug, its never seemed like a clever way to clamp a stem to me? excellent video

[@SIMETHESHAMAN]

Great 3Ding... no follow up?

[@mhgregor]

Fantastic graphics 👏👏👏

[@goldenretriever6261]

I broke a steerer on cheap Chinese frame racing a crit 12 years ago. Hit a pot hole at 50kmh. Nothing broke, and I finished the race, the only thing noticeable was steering was sticking a bit. When I took the stem off I saw that the stem had crushed one half the steerer tube.

[@stevebrown7281]

Good video that I own a Factor Ostro there have been some issues! I have stripped mine down and checked it was all good I added a fair bit of carbon slip to the fork bung re-torqued and did the same with the stem as instructed by Factor. I haven’t had any issues in 5000km this summer but I check it for any movement after nearly every ride just in case. I also ride mine slammed with no spacers above the stem which means the bung is halfway down the steerer tube this must put less stress on the steerer itself👍

[@michaelk.920]

great work, thank you!

[@Phobos_Deimos]

Immense job dude.

[@mitchfajole7737]

merci pour votre réponse, je trouve votre présentation très intéressante sur le contenu et la forme, bravo

[@Martin-on2pp]

Thanks for the vid. It is time that reliable technique and technicians becomes more important than numbers/profit only and good looks only. See also Luescher Technik video.

[@northkyt]

Great job on the animated 3d visualization. Two questions: 1) would it be possible to design a headset that doesn't use a compression ring? 2) why don't manufacturers bond a thin metal sleeve over the steerer tube -- only the part of the steerer tube where the compression ring and bearings might contact. That doesn't seem like it would weigh very much, but it could increase strength and crush resistance.

[@livibam]

I’ve had 2 Zipp SL sprint stems crack on me. Thankfully I wasn’t cycling when I noticed this. Fair to say, I haven’t bought another Zipp stem.

[@Penalist]

Excellent work!

[@martinh6028]

What the hack!? How many days did you spend creating this? Amazing work.

[@JonnyPsyclo]

Love your comparison videos!!! Any chance I can get you to do a comparison of the Rondo HVRT CF1, The Giant Propel Advance Pro 1 and the Orro Venturi Ultegra Tailormade?

[@robertisely2535]

Fantastic video 👍

[@immikemx]

This is by far the best explanation of the issue. Great job! And thanks! What software do you use to do the modeling?

[@bikotic]

Blender 3d

[@ralfralfsen261]

In all bikes I've seen so far, the "compression plug" set directly were the steerer of the fork got cut. So what you show at 4:03 appears incorrect. Also the "compression plug" gets mounted to the steerer prior mounting the fork into the frame.

[@tayloraraya7844]

Awesome video

[@ChillSnaps]

Great balanced video

[@fastestmilkman3840]

The lessons of the story - Get flexible, fewer spacers. Buy a bike that has a longer head tube (Trek H2 fit or similar) Don't buy the hype, integrated cockpit is just a ballache!

[@JMcLeodKC711]

I really liked how video clip at the beginning and the end was a Cervelo. My takeaway is to avoid carbon fiber

[@Tommy31416]

Annoyingly, even Aluminium frame bikes have carbon forks these days - but I agree with you, these carbon steerer tubes are too much risk vs any weight saved

[@durianriders]

@@Tommy31416 alloy steerers can still fail too. They can also unbond. Carbon is fine BUT has to be torqued proper and supported with DEEP enough steerer plugs.

[@abcdabcd-np8bz]

top quality production with that 3D render : ) what program did you use?

[@bikotic]

Blender 3D

[@kargi42]

Canyon solved this issue by having no expander at all on some forks (preload is adjusted from a collar outside), so people can't do stupid things. The steerer is 1 1/4 instead of standart 1 1/8, so it can to endure clamping forces from the stem better. However I am sure somewhere in the world someone over-torque those two bolts..

[@durianriders]

Ive seen 1-1/4 carbon forks CRUSHED from not deep enough plug.

[@kargi42]

@@durianriders come on mate. There is nothing you haven't seen, even if you don't people will forward it to you :)

[@PedroPrego]

What if, just if, based on the sl7 fork snapped there was not any expander plug? It doesn't seem to be on the photo.

[@TheCharnwoodCyclist]

That bike would have been un rideable without the plug and bearing adjustment! I think the plug is there just out of sight in the stem / spacer arrangement, critically the expander didn’t come down to where the metal ring cuts the steerer tube. Hence the updated parts.

[@humprey2]

So, funnily enough... Long before this squeeze test gate and steerer tube SL7 gate, in a good old days of Madone 6, I have already been inserting aluminium tubes inside my semi integrated seat mast as it was a bit too compliant by my standards. I'm a big guy, 6'3" and this was my way of reinforcing it. 10 years have passed and only now manufacturers are catching up ..

[@Jam789]

Nice and informative video

[@marfo6323]

I currently have a basso palta, but getting bored of it. Can you compare it to a pinarello crossista, pinarello grevil, 3t exploro and the new crux? Cheers for the videos

[@noahmonstwil7794]

Love the videos. Can you do a video on tiagra bikes? I’m looking for a new road bike and I don’t want to spend so much money on it

[@durianriders]

Plastic split ring with an alloy sleeve bonded inside the steerer. Specialized do this on a few WT riders bikes. Why not consumer level???

[@mitchfajole7737]

Super, très démonstratif, existe-t-il une version traduite ou avec sous-titre en français ? Merci beaucoup

[@bikotic]

désolé non, pas que je sache, ou comment faire - j'ai utilisé Google translate pour cela, j'espère que cela a fonctionné !

[@jackprick9797]

The spacers and stem length! The more installed spacers and the longer the stem length, the greater the stress and shear force applied to the steerer. Solution? How often does this happen? Would careful and meticulous assembly be sufficient to prevent failure? You can always design for higher shear forces by increasing thickness of carbon, use inner or outer steel sleeves, etc, etc, but is this really needed?

[@NoahStephens]

New fear unlocked

[@JFomo]

1:42 What prevents that ring from falling all the way down the tube? What is holding it in place?

[@sbccbc7471]

There's a stop on the underside of the compression ring.

[@colecoleman1499]

I am going back to aluminium steerer tube and that's the shift we need to see. Bike frame manufacturer can drop much needed weight from the frame and shift that to aluminium tube. I cut my steerer carbon tube too short then just happen to learn about different steerer tube

[@freddyVelo]

It's funny how a solution is to add alloy to the carbon steerer. Which brings us back to just having an alloy steerer. I literally replace or look for a different bike if the bike come with a carbon steerer tube fork. Not risking it.