Shimano denies design problem with Hollowtech cranks despite reports of cracked arms

Solution to these problems. Superbly engineered carbon 12x chorus groupset £1160, SR £2160 (eg chain reaction).

My Ultegra R8000 crank went on my 2017 Canyon Endurace CF SL, it was replaced by Shimano (through Madison their distributor) after I complained to Shimano, this was despite the bike being 4 years old. It had been well cared for and serviced by my LBS. I thought that the pedal had gone as it felt like it had broken and the pedal was moving and slightly oblong shaped feeling as I pedalled, at first couldn't see anything but whilst climbing a fairly sharp but short hill looked down and saw that the crank was split and coming away from the arm. It has left my slightly apprehensive about this type of design as a result of this failure.

I have 2 cranksets break in this manner. Both 6800 ultegra.

I had 8000 ultegra cranks, then about two months ago I felt this flex on the drive side. I thought it was my cleats, but after about 2 more rides i took the bike in to my LBS and sure enough there was a crack in the arm about 5 cm long. I contacted the LBS i ordered them from and Shimano warrantied the cranks. They were about 1.5 years old. Now i just have to wait for the news ones which also may crack.

This happened to a guy in our club this week.

Shimano's engineers are trying to find out if there is a specific cause

There is! It's people pushing too hard on the pedals. I'm pleased to announce that as a result of delicate pushing I have never broken a crank- on the other hand, I only have the boring old non-glued Hollowtech or ordinary alloy spider types

Peak Torque has a vlog on this

It happened to me today on my gravel. 1,5 years old 8000. Disappointed..

I am the latest to suffer this failure.  An Ultegra R8000 crankset.

New creak last week when I was out of the saddle.  Felt the drive side pedal leaning away from the bike, but wasn't sure if this was real or not. 

Small, but definite crack.  Bit relieved that I didn't ride it to failure.

Bike bought in 2018 and only covered 3,350 miles on it. 

A bit unimpressed.  I have already replaced the brake calipers that were leaking fluid last year.  These failures shouldn't really happen.

Yes this week had same problem. Feel like it must be design and or manufacturing problem. 10000 miles 4 years old is surely not a reasonable lifetime for a premium product

I know this thread is a bit old, buy my Ultegra 6800 failed about two weeks ago.  I was going up a hill at the time, but fortunately I was in the saddle and managed to stay upright. 

Unfortunately, I'm having serious difficulties getting in touch with Shimano for some sort of remedy.  Canyon has not been great at helping me out in this matter, but perhaps that's what I get for not buying a bike at my LBS.

My bike is just over four years old - so outside of the parts warranty - and I'm rather put out at the thought of having to purchase a new crankset for a bike that I'm probably only going to use for another year or two.

I've had 2 goes this week at sorting out a creak. I hope it was from not getting the cassette tight enough (isn't it in the region of 50 Nm?) rather than the first signs of danger from a 6800.

I sold a set of R9000 Dura Ace cranks on, the guy who bought them told me a few months later that they'd failed in that way and he'd had quite a bad accident as a result. Then about six months later the same thing happened to mine - three year old R6800 cranks, realised gradually over a couple of hundred miles what the weird feeling was in the pedal stroke, by the time I realised what it was they were coming apart quite badly. Supposedly they're being replaced under warranty, but that's been over a year now and nothing back to replace them yet (the shop handling it for me is doing me a favour as they were originally bought from a different shop as OEM, and that shop no longer exists)...!

I've done nearly 12,000km on my Vaaru with ultegra cranks. Just over two years old.

maybe full length mudguards helped, maybe I've just been lucky. I will pay more attention to any creaking noises and inspect the chainset for any sign of misalignment.

This topic has certainly worked on me! I'm an (almost) lifelong Shimano devotee, and I don't think I've ever had a Shimano component fail unreasonably, but I wouldn't buy one of these 'bonded' efforts.

Whether they admit it or not this looks/feels like a design fault.  Mine failed after around 5000 miles and that was without huge amounts of wet weather or high humidity.  Fortunately I found out what the "clicking" was before it actually snapped and could cause a crash - but not until I swapped out pedals, repalced the BB, changed my cleats.  Did not expect a crank failure but afterwards found some comments on forums showing that this is not an uncommon occurance.  Seems like the QA or the bonding is better on DA.  Meanwhile my 6700 crank is still going strong!

I setup an account here just to post to this. I am on my 4th R8000 crank since April, 2018 - 2 have been warranty replaced but I bought the 4th because I needed a quick replacement (and I have a spare now). All of mine have cracked on the drive side arm joining seam to the left (when looking at the bike as the picture above). This would be the seam that catches most of the sweat as well as all of the pdeal stroke power. Shimano did ask me if I lived in Flordia or on the coast (I don't) on my last warranty exchange - so salt related erosion is a concern of theirs (and I sweat ALOT). Until they make a change to this design, I am not buying Shimano any longer (35+ year customer) - or at least not the crank.