Shimano should be very grateful for channels like yours. This is basically like FREE R&D service for them that can only be exposed OVER a LONG periods of time.
OZ, I can not thank you enough for helping me keep my customers safe. From this day on (March 25 2021), I will inspect every single Shimano bonded crank set. I have many long distance riding customers who ride the beans out of their bikes literally stretching a new chain to the limit in less than two weeks.
I am a strong masher, and I've broken a 105 crankset on a climb with less than 2000km. Since then, I avoid hollow Shimano cr@p and I am happy this way. Shimano Hollow just can't handle leg strength.
@Giuliano Skywalker Exactly, these top-end groupsets are mostly used by pro racing teams with megabuck budgets- simply throw them over the right shoulder once the race/season has finished. Shimano is simply catering for that demand.
@Giuliano Skywalker For Dura Ace and XTR.. sure, those are race components. I expect Ultegra and XT to last. I suppose it depends on the generation though, the regular Deore parts and Tiagra are pretty good right now.
Campagnolo wears in. Shimano wears out. My Ultegras started doing this yesterday. Thinking it was the bottom bracket, I cranked away up the last few hills home, including one steep climb, out of the saddle. Got home and realised the cranks were separating (no cracks though). Now looking to upgrade to vintage square taper.
I had an Ultegra 6800 right hand crank snap off after 2 years riding in the UK. It failed catastrophically and caused me to veer out into the road. I only used the bike for commuting. I eventually managed to persuade the main UK supplier to replace it as I bought it direct in upgrading my worn out 105 gear train. I should have replaced with new 105. There is definitely a design flaw here!
Thank you for this in depth report on what to look for with regards to pre-failure warning signs! I currently own a FC6800 and love it, and would like to continue to use it for a while longer yet. Now thanks to you, I will be able to keep an eye out for the warning signs and most likely will avoid a catastrophic failure incident.
I had a bicycle built in 1984 with the "new" Dura Ace 7400 group. The crank performed great until about 2014 when I noticed a crack on the drive arm about an inch from the center. I can assure you it was not from torque generated by my average strength, probably just old metal fatigue.
Metal especially weaker ones like aluminum will fail one day. This is normal. Do they expect these ULTRA LIGHT WEIGHT cranks to last 100,000 miles? They certain will fail a lot faster.
I have just broken my second R8000 172.5mm crankset. They came equipped on a 2018 Trek Madone. To their credit, Shimano has replaced both under warranty even though the second one was a few months past the 2 year warranty period. I want to stress that the second broken crank was the replacement from Shimano not some other bike etc. Each time the new stuff breaks I go back to my Orbea Mitis 2 which has 105 5500 cranks that would take a bullet and are so worn you can barely see the 105 logo. I think Shimano knows they have a problem with these but are just playing the numbers. I suspect that is why they replace them past their warranty period. I personally believe it is sweat that kills these. I suffer from hyperhidrosis (excessive sweating) and the composition of the sweat seems to break down the adhesive. That is in-spite of the fact that I wipe down the bike after every ride to remove sweat and salt etc. the problem seems to come from the chainring to spider interface area. I disassemble them regularly (2-3 mos) to deep clean and find that area crusted with white powdery substance. This only helps explain the drive side. On the first set I cracked both the drive and non-drive cranks just above the writing on the back of each arm. I also had a tiny crack forming on the outside of the spider as well. Second set cracked on the back side of the drive crank arm but no other damage. At this point I’m debating between selling the replacement when it arrives and buying a 5800 105 or trying to prevent the problem with the R8000 perhaps with caulk in that gap or something. I find that all of Shimano’s products seem to have taken a downward trend in reliability but that also could be due to me having used heavier stuff in the past also. It’s also worth pointing out that not all 105 is safe. The new R7000 105 apparently is bonded as well which means you have to go back to 5800 to be safe.
Over the last 25 years, I've broken 4 Dura Ace cranks. 3 of the 4 have been right in the middle of the threaded pedal hole, going outward to the edges, then abruptly breaking off. These breaks have occurred both on the left and right crank arms. One break occurred in the middle of the drive side crank arm, about half way from the pedal to the spider. In all instances, I went down, once breaking a finger. Shimano was always good about replacing the crank sets. I examine mine but can never any cranks. It just happens all of a sudden. I'm 175 lbs. I do ride in very hilly area's in Northern California typically climbing at least 2k feet per ride, always dry weather riding. Back in the day when I was riding a 150 miles a week, Shimano advised me to replace my cranks every 3 years. Doesn't seem like this should be happening but it does. I don't abuse them, just use them. they are definitely a safety hazard. for me anyway. good luck with yours.
I had an Ultegra 6800 right hand crank arm snap right in half on a ride and had to call the Mrs to pick me up. Took it to my local bike shop and Shimano replaced it for free quickly, but it still made me skeptical about their cranks. I had those cranks for about 3 years before it happened. Been on the replacement cranks for a few years with no problems, but I do keep a close eye on it. By the way, I live in Florida and 99.9% of my rides are in dry, hot weather. No snow, no dirt, very little water, and smooth roads.
It happened to my bike. Bought new in 2016 and after 20 months and 6000 miles the ring gear side crank split in half while riding. I never dreamed a crank would break so if it was cracked I never would have thought anything about it. Was on the inside where you wouldn't really look, but the outside cover was obviously separating as described after it broke. I didn't realize it was supposed to be bonded and thought it was just a cosmetic cap over some internal bolts at the time. Not sure if it was a 6700 or 6800, but took it back to the bike store and Shimano warranty replaced it after a month of discussions with the bike store. They had the bike store send it back to them to investigate. It's an R8000 now. I was getting a creaking and couldn't figure it out, and before it broke I could feel the pedal slightly sinking on the down stroke. I'm now getting a slight creaking on my new bike with R8000 at the bottom of the chain side stroke, but it's not showing anything yet. I'll make sure to check it over well before the two years warranty expires. It seems to me that Shimano should replace these even after two years given the type of failure that is certainly a design fault.
Thanks for this video. I didn't realise it was common issue. I've literally just had an R8000 break in the exact way see here. It looks so much like it, the pictures you've got could be a photo of mine. This was after about 35000km. I then fitted an old 6800, which also failed.
I've been checking our Rotor cranksets, after watching peak torque's video that you mention. Rotor Aldhu is a direct mount modular system where you can get the direct mount rings, or use the rotor 4 arm direct mount spider and I think (not 100% on this) that you can mount shimano 4 arm 110mm BCD rings on that spider. I just bought an r7000 105 crankset, as it was a heck of a lot cheaper, but may get the rotor aldhu system in 24 or 30mm axle when funds allow.
I had the bond start to break on my Ultegra crank that came on my 2016 Giant TCR. The crank felt like I had a stripped pedal like what would happen to our Walmart bikes when we were kids. I couldn't figure out what the problem was and rode it many miles before taking it to the shop where they instantly knew what the problem was. Shimano replaced it, and I never had any additional issues.
6800 spider started coming unglued after 4.5 years, maybe 15 k kms? I thought it was the BB, as a creaking noise started to develop. LBS knew of these failures and found the gap separating. Warranty expired. Replaced with R8000 late last summer. Hopefully it will last a few years until I upgrade the bike. Also, I weigh 78 kg, so not a lot of weight on the cranks
When did Shimano go from Hollow Forged to Hollow Bonded? I want the last HollowForged crank they made. Was that the Shimano Ultegra 6600? If so that is the BIS crank and I want it, infact I want two of them so I dont have to worry about it if I get a new bike.
still riding a full alu crank 30 yrs. old, a bit heavier but fit for purpose. So what... But Ozzys videos are fantastic. The one and only mechanic I trust :-)
Just happened to me (Shimano 6800 RH side). 78kg, 173cm, recreational 600km/month. I am beginning to think this is more prevalent than Shimano care to acknowledge. Was pointed out to me by a Trek mechanic prior to heading out on a 100km event. Told him the symptoms (creak, click and "bent pedal" feel) and he knew straight away what it was and said "yep, it is a common fault" and showed me the separation. Waiting to hear back from Shimano. SRAM now on the radar for the first time ever.
Just experienced my 3rd ultegra 6800 crankset failure in 4 years. Ftp 300w, 80kg. Bike always washed and cleaned after every wet ride. All 3 had spider peel off. Scotland.
It dosen't matter why they fail! Shimano are selling (and profiting) from a component with a known design fault which could cause serious injury or death. My Ultegra failed (3 years old) I demanded a repalcement and got it within two weeks. EU consumer protection actually protects consumers! If the steering wheel in your car failed after 6 years or 200k km would you consider it a warranty item? Thanks for highlighting.
Thanks for this, I have broken 2 Ultegra 8000 cranks in 2 years, both with about 12,000kms on them at time of breaking ,one of which was a Stages dual sided Power meter and thankfully replaced under warranty without fuss both times. I sweat like mad and living in NQ compounds that even further, wash my bike after each ride to reduce sweat corrosion. Next step is to make some sort of dryer to ensure they dry out properly. I do wonder if the sweat may react with the bonding agent to weaken it which causes the breaking?
@@electrocomm Its the better quality and stiffer chainrings that one gets from Ultegra and Dura-Ace that's desired. Just the crankarm weight differences between 5800 and Ultegra / Dura-Ace is nothing. But my 5800 large chain ring isn't straight (true) from day one like my 6800 / R8000 / R9100 large chain rings are.
The drive side crank of my 6800 chainset separated less than 6 months after fitting a new big ring! Replaced it with an R8000 as 6800 was getting difficult to find - annoyed that I couldn't re-use that big ring!
Yo jamás podría creer que el crank podría romperse, jamás. Nunca en mi vida escuché nada al respecto del tema, gracias por nos avisáramos! Saludos desde Río de Janeiro 😷👋
Don't think you could file the rings to swap between models as they are a hollow construction to. A customer of ours said they had strangely high power numbers displaying. I found the crank starting to de bond. So power meter users keep an eye on your numbers, which im sure you do, when you see strange and high readings check your cranks first before logging power meter warranties.
If I ever buy new stuff, I am going with 105. Probably as good or better than the Ultegra I have from about 20 years ago. Back in the 80s I broke several Campy crank arms and a BB spindle. That BB one resulted in a nasty crash during a training ride sprint, and a trip to the emergency room for some stitches in my head.
Gonna have to take slight exeption with your "practical" reasons for failure. I'm a 190 pound, 400w FPT rider. So not a little or weak guy. I unclip right foot first for lights and stops, and also take bumps standing in my pedals, but - always cranks level, left foot forward right foot back. My left foot is the one that bears the most weight. Essentially on the bike I'm left foot dominant. I just removed a cracked r8000 ultegra crankset last night - right side near the pedal threads... just like all the others. Installed a new one (because stages left side ultegra power meter... would've replaced with a SRAM force carbon set) we'll see how long this one lasts... I think shimano is glossing over a serious design flaw. I'm also convinced their r7000 - 9000 series shifters are flawed... They eat cables at a frightening rate.
I have owned Deore, XT, Ultegra and Dura Ace; I now own now GRX. Pleased to relate, I have never had (riding in the UK) any issues. From my experience I think people are wasting their money buying any Shimano crankset model higher than Deore or 105. There has also been problems with Shimano's crankset-based power meters not being accurate.
Had exactly the same happen to me on a DA 9000 3 years ago, starting with an occasional clicking noise whilst riding, checked all the usual suspects, cleats, peddle bearings etc but to no avail. Took it to my service centre the the mechanic did a test ride and "boom" it snapped, completely come apart along the centre joint. Never ridden in the rain and generally dry miles only, it did have signs of corrosion inside.
Ha ha ha ha ha love your last bit on the smoking biker! It reminded me when I worked at Shimano in the early eighties we had our yearly baseball game in LA. They would fly in several of their best workers from Japan for this annual event. 90% would be out in the field with glove in one hand and cigarette on the other chain smoking... It was a blast.
@@lastfm4477 Availability of the new gropusets will probably be an issue for at least a year, plus it usually takes several years for the debonding to occur.
Interesting vid, thanks - I have Sram Red on one of my bikes and had a catastrophic right crank failure a few months ago - the outer casing completely fractured, thankfully close to the end of a long ride. THey were a little over 4 years old and had done c 9000 km, the UK Sram distributor gave a modest discount on the replacement. So not just Shimano - an older bike with 105 (around 8 years old) is still fine.
Had a shimano cramkset replaced as a recall on a wheeler mtb in the nineties in sth australia. Replacement was an acera crankset. We were told it was because some broke in the US
Great information, Oz Cycling. Happened to me also - Ultergra 6800, RH crank. Warning signs (for me) were creaking when putting load on the pedals, e.g. climbing. I thought it was the Bottom Bracket (BB86). Had it checked and serviced, unfortunately, did not inspect the crank. It broke when I was climbing out of the saddle.
the epoxy very probably has a different e-modulus than the aluminium. During strain this results in a stress spike near the bond. Like in welds or glue joints were the common failure point is right beside the joint.
These ultra light weight cranks built around HT are basically disposable after certain miles if the rider outputs a lot of power. It’s best to go hollow forged 105.
Yes you can file a tiny bit off chainring in order to make it fit. Cranks just fail sometimes...I snapped a Zeus Aluminium crank in 1970..Two Campagnolo Record Alloy cranks just above the pedal thread during the 1970’s. Two FSA Carbon cranks had the Alloy pedal insert come out a few years ago and two years ago a Carbon Campagnolo Record LH crank had same issue with pedal insert unbonding..Am 6 ft. 78 kg and don’t produce huge power,so conclude that sometimes parts fail. However Shimano really should re think their bonding process perhaps....
Remember the 7700 Dura ace octalink bottom bracket-in use since 2006 without any service-besides changing the blades,and it‘s still in Perfect condition🤙
Good Morning! Thanks for this video! It is my theme, because I had for years a conflict with shimano because of breaking cranks.... Years ago I owened a premium race bike made by LOOK with a set of premium mavic r-sys wheels and a shimano Da 7800 - in this time all these parts werethe state of the art and used by professionell teams. Than when I cycled in a new street, i accelaretaed my bike from near standing and and the right crank was breaking exact in the thread of the pedals. I nearly crashed with a car on the other line because of the moving of the handlebars. With extrem luck I missed at least this car and I felled with my full weight and with full power in the hendlebar of the bike and on the street. I really had luck in this moment that there was also not a car behind me and that there were people and a doctor who helped me when I was located on the street with bloody legs and body. But the gerat problems came, because shimano never wanted to pas me my demage - and all I expected was a new bik as I lost in the accident; what a shame of shimano germany here! They changed the right crank and the handlebar, that was all - but the carbon spoke of the front wheels, the hole bike carbon bike in the head tube was broken; this LOOK himself checked in a test 2 years later and showed that this was happened at the accident with the bike. I was riding in the meentime a old steel frame with the crank they gave me - but after 6thousend km this new 7800 crank broke again!!!! There was no accident, what a great luck for me! But I needed years to fight with shimano, tjere was never a sorry, never help simply nothing. I had a demage of nearly 10thousend euro with a bike full guarantee having - and shimano, one of the leading companys in the world in cycling, was not able to give me a bike like I had, and this would have neen so simple. I tell you, I studied law and I know exact the rules of the law; i advise a lot of companies in questions about problems with with manufactured parts/items, but what shimano did I never saw before. The job of them should have been finding the reasons for the breaking, to check wheather this hollowtech made cranks are safe. I had a company who is making assesments about accidents and carbon bikes, a company who works sometimes for shimano - these company wanted to check the cranks with me for shimano, but shimano did nothing . The main problem is, that there arise large wholes by splashing the steel in the foams before forging them. Campagnolo knew this problem in the 1990s and changed imediatly the cranks and the production. But shimano never did anything - what a shame for the leading company in cycling parts. Since more than 10 years I now ride campagnolo cranks/parts (super record) and never was a problem again. But I never forget the dispute with shimano germany - all they had to do was giving me a new bike as I had. And this is so simple for a company like shimano! I owened a race bike used by professionell teams and shimano supported a lot of teams - where is the problem giving me back what I lost through the broken crank? My cranks both broke at the same place where the pedals are. Have a good time! Shimano is a company who should be eleminated from the market, the safty of the people are not in the focus of their eyes. What a shame!
Impressive comment, terrible accident - always wonder about the safety standards on bike parts as there are no (except the companies own testing and a few regulations on lights) Given the price-point of bike parts plus the mostley very poor customer service - there should be much more control (DIN - for the Germans here)
@@hyperbalent2775 Good day! Thanks for your comment. The problem for me is not that there happened a accident with a part made by shimano. I never expected this because it was the premium product and a crankset used by Armstrong and others - but always can happen such a break f the crank. But if there happens this, then I expect from a company like shimano a fair and serious solution for my problem, I expect that the cranks and the products are tested and that other riders dont get problems with this parts. The son of my dealer (he was one of the most succesfull riders in the past!) also was a professionell rider in a GS2 team - his crank also broke (DA 7900). I never understand why shimano had a problem to give me back what I lost, and I lost a Teambike with the best parts. Shimano germany send me back my bike with a new crank on the right side, a new handlebar and a new saddle and said it is okay. But I never used this bike again, nobody knows what happend real with this carbon frame. The leading company in testing sucj frames and in making assesments by court wrote a letter to shimano that this bike frame has to be checked, but shimano did nothing. After more than 2 years I sended the frame to LOOK france and they tested them - and the head tube was broken. Shimano always said I shal ride the bike that there is no danger, but the frame was broken! What a shame for this company! The geramn law is simple, it says that the demage at my bike has to be payed by the company - but the company said there is no demage and if you want money go to court and proof there what you say. But this is the wrong way with carbon frames because nobody sees the demage. The professionell teams make a test and than they change the frame, but I can't do t´his as a amateur, I'm not the UCI. Normally shimano has to pay for the skin I lost on the street and the money I lost because I could not work. But I'm a fair sportsman and all I expected was a new bike similar as I lost one. For shimano absolutlly no problem, the groupset ist made by them, the frames are maybe at 200 $ pricepoint direct from the factory and wheels are also cheap for them. The price for a s-works with shimano parts as it is used by Bora for example is for a company like shimano so cheap at the end - but for me over 10tsd euro. I dont want the money, I want a bike back, thats all. And I expect that shimano tets his cranksets for all the other riders. Whats wrong if I only want this? Are I'm not fair? And what did shimano???? This company is a shame! I wrote in this days with the head of a bike magazin and he said me that he never want have my problems with shimano because this company if so stingy and unfair. But this company is the money maker for the magazins in sports, they pay the most money for their advertising inside. So at the end nobody writes negative words about the real practice of this company in business. Anyway, I hope the people change the parts and are taking campagnolo or maybe SRAM for the future. I own both at the moment, a bianchi with super record and a aeroad with etap - and both cranks are still working with more than 6000km.... I hope all stay safe in corona!
They are just building them on the cheap or they would use a nitrogen box etc, so there is no moisture or air in the hollows. Quality control is the real problem and for the price, it's not impressive, My cheap $70 Chinese crank with hollow technology is used from -30 to +95 or so and is in it's third year of flawless riding. A Shimano chain ring costs more than my whole crank set with rings and all! But mine doesn't break. And it's on my 1986 Miyata 310 which doesn't seem to break either! I'd trade it for a new Yoleo though, any takers?
sheeeet. Both my main bikes have 6800 cranks. Just took a close look at them both. My older crank on the high mileage bike looks perfect, like 15,000kms on it. The newer crank on a 2 year old bike I bought used last fall .. has the slightly raised faces on the spider. And it's been noisy lately too. ok - found a R7000 spider and some r7000 chainrings in hong kong. Hard to find cranks these days for decent prices so I ordered them.
Its all about load cycles. What you need to remember is that aluminium is a metal. All metals could have microscopic failure or fatigue zones at some point, its very hard to fully eliminate. The amount of load cycles determines how quickly a fatigued area will propagate. A larger rider, riding at a lower cadence will have a failure of the crank before the same rider at a higher cadence, purely due to loading. (power = torque x rpm) Higher torque, higher force. Also geometry complexity doesn't help. At least these failure modes would be safer than a failure in an older solid crank where it could just instantly pop.
This just happened to my 6800 crankset too. The bike developed a pronounced creak with every pedal stroke. I swapped out the BB30 bottom bracket, not it, tightened up the pedals, not it, different pedals, different shoes, removed/cleaned/reinstalled the seat post, same with the headset, I even removed the seat bag thinking it might have somehow been swaying side to side causing the noise. Then, after reading up on this issue online, I looked at the back side of the right crank arm and saw it - separation all the way along the split line. I guess that one's garbage. I bought it online through a retailer that Shimano has since blocked from selling components to North America too, so I'm guessing any warranty claim is out the window. Oh well, lesson learned I guess.
Fabulous video, very informative. Fortunately I went 105 this time around as Ultegra running costs were too much on previous bike. Thank you for your excellent work 💯
I’ve had 3 sets fail. Absolute disgrace! The 1st set happened 75km from home, hilly route with minimal phone coverage. Limped home & they were replaced. 2nd set, on my way to our local club Crit Championships. I noticed the bent pedal feeling, & glad I did. I’m no superstar, but I’ve got a good enough finish that I would have been in the mix in the final sprint. Imagine a crank letting go & bringing the bunch down!! Again replaced, I’m now on the R8000 crank, which has lasted the least amount of time. 12-18 months I think. This time shimano are asking for original purchase receipt! Why !! Absolutely should be a recall. I’m off to Fair Trading to have a discussion!! I’ll be buying a 105 set & selling the bike. Also will start the process of swapping all 11 bikes I have ( for the family, not just me) to SRAM or Campy!!
Had a FC-MC12 in the 90s, which failed. Thought it was because of my "extreme" riding. Now i know it was material failure, so i wasn't as cool as i thought. This changes my hole life...
I watched this video one day and examined my Ultegra 8000 cranks the next to discover serious cracking and bond failure just in time. My bike was second hand and I'd done 31000 kms, the chainrings still mint but the crank stuffed. Compare that to another second hand bike with Ultegra 6500 on which I've done 88000 kms, the cranks still mint but I've had to replace one set of chainrings. If one goes to 105 to avoid the breaking issue one needs to know that 5800 is good but 7000 is bonded. Also having ridden Ultegra for so long I'm reluctant to go back to 105. But the problem is solved. My son gave me some Ultegra 10 speed 6700 cranks to try and they are perfectly compatible with the 11 speed set up and these reliable forged cranks are no heavier than their modern bonded equivalent.
My 6800 fell victim to the same stress breakage ( UK). I unclip on the right, so that dispels the theory about unclipping on the left maybe putting added stress on the drive side crank.
Another great video. I mentioned this issue last year to some riders who ride Ultegra and DA after I'd started to see more and more reports (after 2019 when I first heard about these drive side crank arm issues). They laughed and said that was probably a SRAM issue. They didn't laugh so much after I directed them to that now well-known Instagram page where riders are continually posting pics of horrendous Ultegra crank arm failures. Humid places? Bonding errors in certain batches? What's going on?
The 6800 crank is notorious for breaking prematurely. I am a huge weight weenie but when it comes to cranks and pedals, two of my bikes use 105 cranks (the other a vision metron and a red 22) and all of my bikes use 105 pedals. 105 components are just built better.
I want my bicycle to get me there and back without breaking. I ride with panniers front and rear and with heavy loads and have the legs to prove it. I'm still riding 8-spd using an Andel triple crank with a 24-36-52 tooth spread and a 13-26 tooth sprocket set in the rear, riding on 559mm by 25 mm inside width rims. My sprockets and chain last longer than 9, 10, or more speeds. My Surly CroMoly frame has handled 7 years and more than 15,000 miles of riding all year long, including subzero Minnesota winters and going through some of the worst pothole seasons in Minnesnowta history. I'll skip the expensive parts and stay with the less expensive RELIABLE parts, thank you very much.
Almost all of the cranks that are showing signs of failure have the same crack propagation in the same area, just up from the pedal threads on the backside. There must be a huge stress riser in that location. If you look at a cutaway or how it's assembled, there's a very sudden squared corner, which seems to back up this idea. The question is: Did the adhesive start failing first causing the crack, or did the crack and loss of structural rigidity/weatherproofing cause the adhesive to fail?
After little less then 2 years, I broke mine. (R8000) I got mine back under warrantee. It failed well within the 40.000 km range. (But I like rough roads) Good advice on what to do when you suffer such a failure! (I assume it will be fixed in dura ace 12 speed... curious)
I have had 2 sets of Ultegra cranks fail. One was the original 6800 series that came on my Giant TCR and the other was the 8000 series Shimano replaced the 6800 series with. They both failed in the same place, which is exactly where this video is showing the fail point. I also know someone that had a Dura Ace 9000 series arm break off as he was putting power down in a corner. That resulted in him coming off the bike and shattering his hip. Unfortunately, I had to put my newest 8000 series(replacement) on because I can't find a bottom bracket bearing for my ROTOR cranks.
I would second peak torque's assessment. If the bonding is not uniform the interior will breath allowing moisture to get inside. Aluminium is highly corrosive and then you get expansion causing the bonding to fail. Once the structure is comprimised then all strength is lost. I don't believe it is realated to heavier riders. The crankset failure rate is unacceptably to high, shimano should replace out of warranty cranks failing by this cause ( they know) and fix it in the new coming generation.
From my experience, you can break all types of cranks if you ride your bike out of the saddle long enough. I did this riding style very extreme 20 years ago and managed to break two 105 cranks and also a cheap steel crank. It seems that uneven torque is bad for cranks in general.
After 20 years of being a loyal Shimano fan I'm switching to SRAM for this very reason. It's sad they don't make things like they used to. I have a Shimano 6600 Ultegra group set that has been incredible and is still on my training bike after 15 years.
Since they decided to go with glue why didn’t they just make the leap to carbon fiber instead? Gluing aluminum seems like a horrible option. Why didn’t they weld the seam instead? Seems to run counter to logic other than cost savings and speed of production or something
Shimano should be very grateful for channels like yours. This is basically like FREE R&D service for them that can only be exposed OVER a LONG periods of time.
And here we are....... 2 years later. After 12 years!! A recall.
OZ, I can not thank you enough for helping me keep my customers safe. From this day on (March 25 2021), I will inspect every single Shimano bonded crank set. I have many long distance riding customers who ride the beans out of their bikes literally stretching a new chain to the limit in less than two weeks.
Someone wears out a chain in 2 weeks. Wow.
2 weeks? I broke my chain day 1 lol , I have to change my BB every year lol
You don't stretch a chain, debris wear away the inner load bearing surfaces if they are not clean and lubricated correctly.
Yeah right.
105 components are so robust yet they deliver precise shifting, braking, and power transmission. Never had any issues with 105 components.
But how can you stand the extra grams? /s
@Perpetual Grin Used 105 crankset for 15,000km and still no issues since I regularly clean it.
@@Trammael The extra grams are negligible unless you are pro.
I am a strong masher, and I've broken a 105 crankset on a climb with less than 2000km. Since then, I avoid hollow Shimano cr@p and I am happy this way. Shimano Hollow just can't handle leg strength.
There’s 105 that breaks too.
Thanks you just made me feel a little bit smarter for having bought 105 in the first place.
I'm so lucky I wouldn't afford more than my 105. Still rolling strong.
Mine too
No issue with any of my 105 cranks, ever.
@Giuliano Skywalker Exactly, these top-end groupsets are mostly used by pro racing teams with megabuck budgets- simply throw them over the right shoulder once the race/season has finished. Shimano is simply catering for that demand.
@Giuliano Skywalker For Dura Ace and XTR.. sure, those are race components. I expect Ultegra and XT to last. I suppose it depends on the generation though, the regular Deore parts and Tiagra are pretty good right now.
Set it & forget it 👌🏼
Campagnolo wears in. Shimano wears out.
My Ultegras started doing this yesterday. Thinking it was the bottom bracket, I cranked away up the last few hills home, including one steep climb, out of the saddle. Got home and realised the cranks were separating (no cracks though). Now looking to upgrade to vintage square taper.
I had an Ultegra 6800 right hand crank snap off after 2 years riding in the UK. It failed catastrophically and caused me to veer out into the road. I only used the bike for commuting. I eventually managed to persuade the main UK supplier to replace it as I bought it direct in upgrading my worn out 105 gear train. I should have replaced with new 105. There is definitely a design flaw here!
Love my 105 R7000 crankset strong, reliable, precise what more do you need.
Thank you for this in depth report on what to look for with regards to pre-failure warning signs!
I currently own a FC6800 and love it, and would like to continue to use it for a while longer yet. Now thanks to you, I will be able to keep an eye out for the warning signs and most likely will avoid a catastrophic failure incident.
Makes me pleased I’m riding 105, specially as I’m quite a unit😉 Well done Steve, enjoyed and thanks for the info😊👍
I had a bicycle built in 1984 with the "new" Dura Ace 7400 group. The crank performed great until about 2014 when I noticed a crack on the drive arm about an inch from the center. I can assure you it was not from torque generated by my average strength, probably just old metal fatigue.
Metal especially weaker ones like aluminum will fail one day. This is normal. Do they expect these ULTRA LIGHT WEIGHT cranks to last 100,000 miles? They certain will fail a lot faster.
I have just broken my second R8000 172.5mm crankset. They came equipped on a 2018 Trek Madone. To their credit, Shimano has replaced both under warranty even though the second one was a few months past the 2 year warranty period. I want to stress that the second broken crank was the replacement from Shimano not some other bike etc. Each time the new stuff breaks I go back to my Orbea Mitis 2 which has 105 5500 cranks that would take a bullet and are so worn you can barely see the 105 logo. I think Shimano knows they have a problem with these but are just playing the numbers. I suspect that is why they replace them past their warranty period.
I personally believe it is sweat that kills these. I suffer from hyperhidrosis (excessive sweating) and the composition of the sweat seems to break down the adhesive. That is in-spite of the fact that I wipe down the bike after every ride to remove sweat and salt etc. the problem seems to come from the chainring to spider interface area. I disassemble them regularly (2-3 mos) to deep clean and find that area crusted with white powdery substance. This only helps explain the drive side. On the first set I cracked both the drive and non-drive cranks just above the writing on the back of each arm. I also had a tiny crack forming on the outside of the spider as well. Second set cracked on the back side of the drive crank arm but no other damage.
At this point I’m debating between selling the replacement when it arrives and buying a 5800 105 or trying to prevent the problem with the R8000 perhaps with caulk in that gap or something. I find that all of Shimano’s products seem to have taken a downward trend in reliability but that also could be due to me having used heavier stuff in the past also.
It’s also worth pointing out that not all 105 is safe. The new R7000 105 apparently is bonded as well which means you have to go back to 5800 to be safe.
Over the last 25 years, I've broken 4 Dura Ace cranks. 3 of the 4 have been right in the middle of the threaded pedal hole, going outward to the edges, then abruptly breaking off. These breaks have occurred both on the left and right crank arms. One break occurred in the middle of the drive side crank arm, about half way from the pedal to the spider. In all instances, I went down, once breaking a finger. Shimano was always good about replacing the crank sets. I examine mine but can never any cranks. It just happens all of a sudden. I'm 175 lbs. I do ride in very hilly area's in Northern California typically climbing at least 2k feet per ride, always dry weather riding. Back in the day when I was riding a 150 miles a week, Shimano advised me to replace my cranks every 3 years. Doesn't seem like this should be happening but it does. I don't abuse them, just use them. they are definitely a safety hazard. for me anyway. good luck with yours.
I had an Ultegra 6800 right hand crank arm snap right in half on a ride and had to call the Mrs to pick me up. Took it to my local bike shop and Shimano replaced it for free quickly, but it still made me skeptical about their cranks. I had those cranks for about 3 years before it happened. Been on the replacement cranks for a few years with no problems, but I do keep a close eye on it. By the way, I live in Florida and 99.9% of my rides are in dry, hot weather. No snow, no dirt, very little water, and smooth roads.
But with an extreme normalized humidity level. Peak Torque had a sampling of failures and almost all were in tropical to subtropical areas.
It happened to my bike. Bought new in 2016 and after 20 months and 6000 miles the ring gear side crank split in half while riding. I never dreamed a crank would break so if it was cracked I never would have thought anything about it. Was on the inside where you wouldn't really look, but the outside cover was obviously separating as described after it broke. I didn't realize it was supposed to be bonded and thought it was just a cosmetic cap over some internal bolts at the time. Not sure if it was a 6700 or 6800, but took it back to the bike store and Shimano warranty replaced it after a month of discussions with the bike store. They had the bike store send it back to them to investigate. It's an R8000 now. I was getting a creaking and couldn't figure it out, and before it broke I could feel the pedal slightly sinking on the down stroke. I'm now getting a slight creaking on my new bike with R8000 at the bottom of the chain side stroke, but it's not showing anything yet. I'll make sure to check it over well before the two years warranty expires. It seems to me that Shimano should replace these even after two years given the type of failure that is certainly a design fault.
I was completely unaware of this. Carefully checked both my bikes with Ultegra cranks. They are ok. But will now check this from time to time. Thx!!
Thanks for this video. I didn't realise it was common issue. I've literally just had an R8000 break in the exact way see here. It looks so much like it, the pictures you've got could be a photo of mine. This was after about 35000km. I then fitted an old 6800, which also failed.
My 6800 spider failed. It was out of warranty but LBS got a free upgrade to newer crankset for me.
It would be nice if we had such a good channel in Germany. Greets from here!!!!
After 2 years we get the recall. Good reporting on the issue!
Well I'm here in 2023 because shimano now recognizes a problem an has started a massive recall
And I just had a similar issue with a Tiagra 4700….
I've been checking our Rotor cranksets, after watching peak torque's video that you mention. Rotor Aldhu is a direct mount modular system where you can get the direct mount rings, or use the rotor 4 arm direct mount spider and I think (not 100% on this) that you can mount shimano 4 arm 110mm BCD rings on that spider. I just bought an r7000 105 crankset, as it was a heck of a lot cheaper, but may get the rotor aldhu system in 24 or 30mm axle when funds allow.
I had the bond start to break on my Ultegra crank that came on my 2016 Giant TCR. The crank felt like I had a stripped pedal like what would happen to our Walmart bikes when we were kids. I couldn't figure out what the problem was and rode it many miles before taking it to the shop where they instantly knew what the problem was. Shimano replaced it, and I never had any additional issues.
6800 spider started coming unglued after 4.5 years, maybe 15 k kms? I thought it was the BB, as a creaking noise started to develop. LBS knew of these failures and found the gap separating. Warranty expired. Replaced with R8000 late last summer. Hopefully it will last a few years until I upgrade the bike. Also, I weigh 78 kg, so not a lot of weight on the cranks
In the past, even cheap bicycle cranks never broke. It was simply imposible. But nowadays, even very expensive ones can get damaged.
When did Shimano go from Hollow Forged to Hollow Bonded? I want the last HollowForged crank they made. Was that the Shimano Ultegra 6600? If so that is the BIS crank and I want it, infact I want two of them so I dont have to worry about it if I get a new bike.
still riding a full alu crank 30 yrs. old, a bit heavier but fit for purpose. So what...
But Ozzys videos are fantastic. The one and only mechanic I trust :-)
Just happened to me (Shimano 6800 RH side). 78kg, 173cm, recreational 600km/month. I am beginning to think this is more prevalent than Shimano care to acknowledge. Was pointed out to me by a Trek mechanic prior to heading out on a 100km event. Told him the symptoms (creak, click and "bent pedal" feel) and he knew straight away what it was and said "yep, it is a common fault" and showed me the separation. Waiting to hear back from Shimano. SRAM now on the radar for the first time ever.
yea Haaaaaaaaaaaa, I'm so glad I stayed with 105, and didn't "upgrade" to Ultegra, thanks for the info
Just experienced my 3rd ultegra 6800 crankset failure in 4 years. Ftp 300w, 80kg. Bike always washed and cleaned after every wet ride. All 3 had spider peel off. Scotland.
Good inspection to see those little weasely cracks.. Sterling mate
It dosen't matter why they fail! Shimano are selling (and profiting) from a component with a known design fault which could cause serious injury or death. My Ultegra failed (3 years old) I demanded a repalcement and got it within two weeks. EU consumer protection actually protects consumers! If the steering wheel in your car failed after 6 years or 200k km would you consider it a warranty item? Thanks for highlighting.
This happened to me. All the signs you listed is what happened to. Shimano replaced my crankset. I’m certain they are aware of the issue.
Thanks for this, I have broken 2 Ultegra 8000 cranks in 2 years, both with about 12,000kms on them at time of breaking ,one of which was a Stages dual sided Power meter and thankfully replaced under warranty without fuss both times.
I sweat like mad and living in NQ compounds that even further, wash my bike after each ride to reduce sweat corrosion. Next step is to make some sort of dryer to ensure they dry out properly.
I do wonder if the sweat may react with the bonding agent to weaken it which causes the breaking?
This would be my theory as I also sweat like living mad and live in a very NON-humid area and my FC-6800 unbonded, starting at the spider.
my question: how are the Shimano GRX cranks constructed? Are they constructed in two parts like the ULTEGRA / DURA ACE or in one part like the 105
Doesn't look like the right/drive side is bonded like ultegra/DA
My new SL7 Tarmac S-Works I picked up yesterday comes stock with 9100 crack ready cranks lol.
Dura-ache!
105 5800 FTW. better cut 50g of belly fat and spend the money on a powermeter :D
My 105 is still fine after 24 years.... just a thought.
@@electrocomm Its the better quality and stiffer chainrings that one gets from Ultegra and Dura-Ace that's desired. Just the crankarm weight differences between 5800 and Ultegra / Dura-Ace is nothing. But my 5800 large chain ring isn't straight (true) from day one like my 6800 / R8000 / R9100 large chain rings are.
Subscribed after watching two of your videos. Excellently done!
The drive side crank of my 6800 chainset separated less than 6 months after fitting a new big ring! Replaced it with an R8000 as 6800 was getting difficult to find - annoyed that I couldn't re-use that big ring!
Yo jamás podría creer que el crank podría romperse, jamás. Nunca en mi vida escuché nada al respecto del tema, gracias por nos avisáramos!
Saludos desde Río de Janeiro 😷👋
great vid i use
praxis cranks, i really liked swapping to praxis for a few years.... back on the new r8000 waiting for that feeling!
Don't think you could file the rings to swap between models as they are a hollow construction to.
A customer of ours said they had strangely high power numbers displaying. I found the crank starting to de bond. So power meter users keep an eye on your numbers, which im sure you do, when you see strange and high readings check your cranks first before logging power meter warranties.
If I ever buy new stuff, I am going with 105. Probably as good or better than the Ultegra I have from about 20 years ago. Back in the 80s I broke several Campy crank arms and a BB spindle. That BB one resulted in a nasty crash during a training ride sprint, and a trip to the emergency room for some stitches in my head.
Gonna have to take slight exeption with your "practical" reasons for failure.
I'm a 190 pound, 400w FPT rider. So not a little or weak guy.
I unclip right foot first for lights and stops, and also take bumps standing in my pedals, but - always cranks level, left foot forward right foot back.
My left foot is the one that bears the most weight. Essentially on the bike I'm left foot dominant.
I just removed a cracked r8000 ultegra crankset last night - right side near the pedal threads... just like all the others.
Installed a new one (because stages left side ultegra power meter... would've replaced with a SRAM force carbon set) we'll see how long this one lasts...
I think shimano is glossing over a serious design flaw. I'm also convinced their r7000 - 9000 series shifters are flawed...
They eat cables at a frightening rate.
I have owned Deore, XT, Ultegra and Dura Ace; I now own now GRX. Pleased to relate, I have never had (riding in the UK) any issues. From my experience I think people are wasting their money buying any Shimano crankset model higher than Deore or 105.
There has also been problems with Shimano's crankset-based power meters not being accurate.
Having broken a couple of 7800 cranks I check my 8000's fairly regularly
i have a 5800 105 and was looking this week to go for the ultegra 6800, Am i glad i had this come up on my youtube feed ,Many thanks NO 6800 FOR ME
Had exactly the same happen to me on a DA 9000 3 years ago, starting with an occasional clicking noise whilst riding, checked all the usual suspects, cleats, peddle bearings etc but to no avail. Took it to my service centre the the mechanic did a test ride and "boom" it snapped, completely come apart along the centre joint. Never ridden in the rain and generally dry miles only, it did have signs of corrosion inside.
Ha ha ha ha ha love your last bit on the smoking biker! It reminded me when I worked at Shimano in the early eighties we had our yearly baseball game in LA. They would fly in several of their best workers from Japan for this annual event. 90% would be out in the field with glove in one hand and cigarette on the other chain smoking... It was a blast.
Great presentation on the issue. You really did a thorough job. Hopefully Shimano will fix the issue in their next round of groupsets.
R8100 and R9200 are here! So we will soon see once they are seen in the wild.
@@lastfm4477 Availability of the new gropusets will probably be an issue for at least a year, plus it usually takes several years for the debonding to occur.
Interesting vid, thanks - I have Sram Red on one of my bikes and had a catastrophic right crank failure a few months ago - the outer casing completely fractured, thankfully close to the end of a long ride. THey were a little over 4 years old and had done c 9000 km, the UK Sram distributor gave a modest discount on the replacement. So not just Shimano - an older bike with 105 (around 8 years old) is still fine.
Had a shimano cramkset replaced as a recall on a wheeler mtb in the nineties in sth australia. Replacement was an acera crankset. We were told it was because some broke in the US
Great information, Oz Cycling. Happened to me also - Ultergra 6800, RH crank. Warning signs (for me) were creaking when putting load on the pedals, e.g. climbing. I thought it was the Bottom Bracket (BB86). Had it checked and serviced, unfortunately, did not inspect the crank. It broke when I was climbing out of the saddle.
Hope you didn't injure yourself Tony?
@@stevenleffanue Thankfully, I did not fall off. All was good. Mostly embarrass having to take a taxi home!
Now why do road cranks fail but the XTR XT SLX are pretty much bullet proof, are MTB cranks HF and not HB?
the epoxy very probably has a different e-modulus than the aluminium. During strain this results in a stress spike near the bond. Like in welds or glue joints were the common failure point is right beside the joint.
These ultra light weight cranks built around HT are basically disposable after certain miles if the rider outputs a lot of power. It’s best to go hollow forged 105.
HT is hollow tech and 105 has it. You mean HB - hollow BONDED.
Yes you can file a tiny bit off chainring in order to make it fit. Cranks just fail sometimes...I snapped a Zeus Aluminium crank in 1970..Two Campagnolo Record Alloy cranks just above the pedal thread during the 1970’s. Two FSA Carbon cranks had the Alloy pedal insert come out a few years ago and two years ago a Carbon Campagnolo Record LH crank had same issue with pedal insert unbonding..Am 6 ft. 78 kg and don’t produce huge power,so conclude that sometimes parts fail. However Shimano really should re think their bonding process perhaps....
Campagnolo Record alloy also cracked between the spider arm and right arm due to a stress riser.
As a follow up, can you discuss other brands of compatible cranks that are available with a 24mm spindle?
Rotor is one
Sounds like a moisture problem for sure. I live in dry Arizona and haven’t seen any broken crank arms.
"Remember the old shimano 600?"..haha i'm still riding one 👍
Remember the 7700 Dura ace octalink
bottom bracket-in use since 2006 without any service-besides changing the blades,and it‘s still in Perfect condition🤙
I've hot a set of wheels with 600 hubs still rolling along.
Me too🙂🏴
Best looking Shimano gruppo ever imo.
The hollow crankset was doomed from the beginning according to a mechanical engineer I know .
Good Morning! Thanks for this video! It is my theme, because I had for years a conflict with shimano because of breaking cranks.... Years ago I owened a premium race bike made by LOOK with a set of premium mavic r-sys wheels and a shimano Da 7800 - in this time all these parts werethe state of the art and used by professionell teams. Than when I cycled in a new street, i accelaretaed my bike from near standing and and the right crank was breaking exact in the thread of the pedals. I nearly crashed with a car on the other line because of the moving of the handlebars. With extrem luck I missed at least this car and I felled with my full weight and with full power in the hendlebar of the bike and on the street. I really had luck in this moment that there was also not a car behind me and that there were people and a doctor who helped me when I was located on the street with bloody legs and body. But the gerat problems came, because shimano never wanted to pas me my demage - and all I expected was a new bik as I lost in the accident; what a shame of shimano germany here! They changed the right crank and the handlebar, that was all - but the carbon spoke of the front wheels, the hole bike carbon bike in the head tube was broken; this LOOK himself checked in a test 2 years later and showed that this was happened at the accident with the bike. I was riding in the meentime a old steel frame with the crank they gave me - but after 6thousend km this new 7800 crank broke again!!!! There was no accident, what a great luck for me!
But I needed years to fight with shimano, tjere was never a sorry, never help simply nothing. I had a demage of nearly 10thousend euro with a bike full guarantee having - and shimano, one of the leading companys in the world in cycling, was not able to give me a bike like I had, and this would have neen so simple. I tell you, I studied law and I know exact the rules of the law; i advise a lot of companies in questions about problems with with manufactured parts/items, but what shimano did I never saw before. The job of them should have been finding the reasons for the breaking, to check wheather this hollowtech made cranks are safe. I had a company who is making assesments about accidents and carbon bikes, a company who works sometimes for shimano - these company wanted to check the cranks with me for shimano, but shimano did nothing . The main problem is, that there arise large wholes by splashing the steel in the foams before forging them. Campagnolo knew this problem in the 1990s and changed imediatly the cranks and the production. But shimano never did anything - what a shame for the leading company in cycling parts.
Since more than 10 years I now ride campagnolo cranks/parts (super record) and never was a problem again. But I never forget the dispute with shimano germany - all they had to do was giving me a new bike as I had. And this is so simple for a company like shimano! I owened a race bike used by professionell teams and shimano supported a lot of teams - where is the problem giving me back what I lost through the broken crank? My cranks both broke at the same place where the pedals are.
Have a good time! Shimano is a company who should be eleminated from the market, the safty of the people are not in the focus of their eyes. What a shame!
Wow, sorry to hear that. That is terrible.😯
Impressive comment, terrible accident - always wonder about the safety standards on bike parts as there are no (except the companies own testing and a few regulations on lights) Given the price-point of bike parts plus the mostley very poor customer service - there should be much more control (DIN - for the Germans here)
@@hyperbalent2775 Good day! Thanks for your comment. The problem for me is not that there happened a accident with a part made by shimano. I never expected this because it was the premium product and a crankset used by Armstrong and others - but always can happen such a break f the crank. But if there happens this, then I expect from a company like shimano a fair and serious solution for my problem, I expect that the cranks and the products are tested and that other riders dont get problems with this parts. The son of my dealer (he was one of the most succesfull riders in the past!) also was a professionell rider in a GS2 team - his crank also broke (DA 7900). I never understand why shimano had a problem to give me back what I lost, and I lost a Teambike with the best parts. Shimano germany send me back my bike with a new crank on the right side, a new handlebar and a new saddle and said it is okay. But I never used this bike again, nobody knows what happend real with this carbon frame. The leading company in testing sucj frames and in making assesments by court wrote a letter to shimano that this bike frame has to be checked, but shimano did nothing. After more than 2 years I sended the frame to LOOK france and they tested them - and the head tube was broken. Shimano always said I shal ride the bike that there is no danger, but the frame was broken! What a shame for this company! The geramn law is simple, it says that the demage at my bike has to be payed by the company - but the company said there is no demage and if you want money go to court and proof there what you say. But this is the wrong way with carbon frames because nobody sees the demage. The professionell teams make a test and than they change the frame, but I can't do t´his as a amateur, I'm not the UCI. Normally shimano has to pay for the skin I lost on the street and the money I lost because I could not work. But I'm a fair sportsman and all I expected was a new bike similar as I lost one. For shimano absolutlly no problem, the groupset ist made by them, the frames are maybe at 200 $ pricepoint direct from the factory and wheels are also cheap for them. The price for a s-works with shimano parts as it is used by Bora for example is for a company like shimano so cheap at the end - but for me over 10tsd euro. I dont want the money, I want a bike back, thats all. And I expect that shimano tets his cranksets for all the other riders. Whats wrong if I only want this? Are I'm not fair? And what did shimano???? This company is a shame! I wrote in this days with the head of a bike magazin and he said me that he never want have my problems with shimano because this company if so stingy and unfair. But this company is the money maker for the magazins in sports, they pay the most money for their advertising inside. So at the end nobody writes negative words about the real practice of this company in business.
Anyway, I hope the people change the parts and are taking campagnolo or maybe SRAM for the future. I own both at the moment, a bianchi with super record and a aeroad with etap - and both cranks are still working with more than 6000km....
I hope all stay safe in corona!
I have Shimano FC-RS510 46-36 | 165 mm. Heavier than those fully hollow cranksets but I'm very happy with them.
They are just building them on the cheap or they would use a nitrogen box etc, so there is no moisture or air in the hollows. Quality control is the real problem and for the price, it's not impressive, My cheap $70 Chinese crank with hollow technology is used from -30 to +95 or so and is in it's third year of flawless riding. A Shimano chain ring costs more than my whole crank set with rings and all! But mine doesn't break. And it's on my 1986 Miyata 310 which doesn't seem to break either! I'd trade it for a new Yoleo though, any takers?
Spice it up a little bloke! Throw in a carton.... :-)
sheeeet. Both my main bikes have 6800 cranks. Just took a close look at them both. My older crank on the high mileage bike looks perfect, like 15,000kms on it. The newer crank on a 2 year old bike I bought used last fall .. has the slightly raised faces on the spider. And it's been noisy lately too. ok - found a R7000 spider and some r7000 chainrings in hong kong. Hard to find cranks these days for decent prices so I ordered them.
Its all about load cycles. What you need to remember is that aluminium is a metal. All metals could have microscopic failure or fatigue zones at some point, its very hard to fully eliminate. The amount of load cycles determines how quickly a fatigued area will propagate. A larger rider, riding at a lower cadence will have a failure of the crank before the same rider at a higher cadence, purely due to loading. (power = torque x rpm) Higher torque, higher force. Also geometry complexity doesn't help. At least these failure modes would be safer than a failure in an older solid crank where it could just instantly pop.
Intricate geometry adds stiffness to the design, think old Gilco tubing Colnago used to stiffen up frames, or chainstay crimping.
Thought I would start purchasing higher end replacement parts. My new XT crank is glued.
This just happened to my 6800 crankset too. The bike developed a pronounced creak with every pedal stroke. I swapped out the BB30 bottom bracket, not it, tightened up the pedals, not it, different pedals, different shoes, removed/cleaned/reinstalled the seat post, same with the headset, I even removed the seat bag thinking it might have somehow been swaying side to side causing the noise. Then, after reading up on this issue online, I looked at the back side of the right crank arm and saw it - separation all the way along the split line.
I guess that one's garbage. I bought it online through a retailer that Shimano has since blocked from selling components to North America too, so I'm guessing any warranty claim is out the window.
Oh well, lesson learned I guess.
Consumers should request replacement of all cranksets without negotiating with shimano
Nice and simple explanation as always. How can someone smoke and cycle unless he has only start cycling and finding it hard to stop.
There were even pro soccer players playing in the first national league in Germany in the past who smoked ;-)
The bike's a Cipollini. That's got to be good for an extra kilowatt in a sprint finish, so smoke 'em if ya got'em.
@@simonm1447 ... who* smoked. Even smoking athletes are still persons, not things.
Fabulous video, very informative. Fortunately I went 105 this time around as Ultegra running costs were too much on previous bike. Thank you for your excellent work 💯
how is the crankset not a safety critical component? that snaps on a sprint and you're going down hard
I’ve had 3 sets fail. Absolute disgrace! The 1st set happened 75km from home, hilly route with minimal phone coverage. Limped home & they were replaced. 2nd set, on my way to our local club Crit Championships. I noticed the bent pedal feeling, & glad I did. I’m no superstar, but I’ve got a good enough finish that I would have been in the mix in the final sprint. Imagine a crank letting go & bringing the bunch down!! Again replaced, I’m now on the R8000 crank, which has lasted the least amount of time. 12-18 months I think. This time shimano are asking for original purchase receipt! Why !! Absolutely should be a recall. I’m off to Fair Trading to have a discussion!! I’ll be buying a 105 set & selling the bike. Also will start the process of swapping all 11 bikes I have ( for the family, not just me) to SRAM or Campy!!
You seem smart enough to manufacture /design your own cranksets.
Had a FC-MC12 in the 90s, which failed. Thought it was because of my "extreme" riding. Now i know it was material failure, so i wasn't as cool as i thought. This changes my hole life...
I watched this video one day and examined my Ultegra 8000 cranks the next to discover serious cracking and bond failure just in time. My bike was second hand and I'd done 31000 kms, the chainrings still mint but the crank stuffed. Compare that to another second hand bike with Ultegra 6500 on which I've done 88000 kms, the cranks still mint but I've had to replace one set of chainrings. If one goes to 105 to avoid the breaking issue one needs to know that 5800 is good but 7000 is bonded. Also having ridden Ultegra for so long I'm reluctant to go back to 105. But the problem is solved. My son gave me some Ultegra 10 speed 6700 cranks to try and they are perfectly compatible with the 11 speed set up and these reliable forged cranks are no heavier than their modern bonded equivalent.
As long as you are happy with the larger chainring sizes of 6700 ?
@@stevenleffanue Well in the 70s I was riding Record 54/46 with a 13 - 21 5 speed freewheel so 53/39 with 11 - 25 is a bit of a doddle.
My 6800 fell victim to the same stress breakage ( UK). I unclip on the right, so that dispels the theory about unclipping on the left maybe putting added stress on the drive side crank.
Another great video.
I mentioned this issue last year to some riders who ride Ultegra and DA after I'd started to see more and more reports (after 2019 when I first heard about these drive side crank arm issues). They laughed and said that was probably a SRAM issue. They didn't laugh so much after I directed them to that now well-known Instagram page where riders are continually posting pics of horrendous Ultegra crank arm failures.
Humid places?
Bonding errors in certain batches?
What's going on?
Nice cracksets.
The 6800 crank is notorious for breaking prematurely.
I am a huge weight weenie but when it comes to cranks and pedals, two of my bikes use 105 cranks (the other a vision metron and a red 22) and all of my bikes use 105 pedals.
105 components are just built better.
I want my bicycle to get me there and back without breaking. I ride with panniers front and rear and with heavy loads and have the legs to prove it. I'm still riding 8-spd using an Andel triple crank with a 24-36-52 tooth spread and a 13-26 tooth sprocket set in the rear, riding on 559mm by 25 mm inside width rims. My sprockets and chain last longer than 9, 10, or more speeds. My Surly CroMoly frame has handled 7 years and more than 15,000 miles of riding all year long, including subzero Minnesota winters and going through some of the worst pothole seasons in Minnesnowta history. I'll skip the expensive parts and stay with the less expensive RELIABLE parts, thank you very much.
Any word on the MTB cranksets coming apart. I have a 985 XTR double crankset and I really do love them.
Almost all of the cranks that are showing signs of failure have the same crack propagation in the same area, just up from the pedal threads on the backside. There must be a huge stress riser in that location. If you look at a cutaway or how it's assembled, there's a very sudden squared corner, which seems to back up this idea. The question is: Did the adhesive start failing first causing the crack, or did the crack and loss of structural rigidity/weatherproofing cause the adhesive to fail?
It is hard for me to imagine how would such crack form without bond failure. So i am quessing bond failure was first.
Wow so after 2 years they FINALLY acknowledged this??? Just got an email from a local bike shop about this recall.
After little less then 2 years, I broke mine. (R8000) I got mine back under warrantee. It failed well within the 40.000 km range. (But I like rough roads)
Good advice on what to do when you suffer such a failure!
(I assume it will be fixed in dura ace 12 speed... curious)
... less than* ...
@@einundsiebenziger5488 I’m not native so.. am I allowed to make a mistake?
I have had 2 sets of Ultegra cranks fail. One was the original 6800 series that came on my Giant TCR and the other was the 8000 series Shimano replaced the 6800 series with. They both failed in the same place, which is exactly where this video is showing the fail point. I also know someone that had a Dura Ace 9000 series arm break off as he was putting power down in a corner. That resulted in him coming off the bike and shattering his hip. Unfortunately, I had to put my newest 8000 series(replacement) on because I can't find a bottom bracket bearing for my ROTOR cranks.
Nice to know it's not only me with this issue, but it's not a good situation for Shimano.
Is the Ultegra FC-6600 from about 2006/7 or so forged or bonded? It looks a lot more like that 105 arm
I appreciate the video but now have had two 105 cranks break over the past three years (5800 and R7000). So they are not a guaranteed option.
Thanks for the information mate, 105 it is then if my Ultegra crank fails.
I would second peak torque's assessment. If the bonding is not uniform the interior will breath allowing moisture to get inside. Aluminium is highly corrosive and then you get expansion causing the bonding to fail. Once the structure is comprimised then all strength is lost. I don't believe it is realated to heavier riders. The crankset failure rate is unacceptably to high, shimano should replace out of warranty cranks failing by this cause ( they know) and fix it in the new coming generation.
From my experience, you can break all types of cranks if you ride your bike out of the saddle long enough. I did this riding style very extreme 20 years ago and managed to break two 105 cranks and also a cheap steel crank. It seems that uneven torque is bad for cranks in general.
Worth noting. Thanx Rainer
this is a failure on how shimano is putting together two dissimlar metals hambini did a video on his when it failed.
I have yet to see a broken one. What does it look like??
After 20 years of being a loyal Shimano fan I'm switching to SRAM for this very reason.
It's sad they don't make things like they used to. I have a Shimano 6600 Ultegra group set that has been incredible and is still on my training bike after 15 years.
I wouldn't join the SRAM bandwagon.
Thank you for that great public service.
I’m sure Harley did a video where the cast 105 crank arms with Absolute Black chainring is lighter than a Dura Ace chainset.
Since they decided to go with glue why didn’t they just make the leap to carbon fiber instead? Gluing aluminum seems like a horrible option. Why didn’t they weld the seam instead? Seems to run counter to logic other than cost savings and speed of production or something
Unbelievable how it took them so long to officially recognize this as a systemic problem...
At 4:31. Shimano 105/R7000 is affordable, light, performs, and lasts. A great buy in my opinion.
They finally issued a recall starting in the US