I upgraded to the Shimano 6800 Ultegra group set from CWC a few years back. Within a few months, jumping up a steep gradient, my right foot literally hit the floor when the crank arm on the drive side broke in half (see pic). Imagine my shock after struggling to stay upright, not knowing what the hell just happened, to see my right foot on the ground with half a crank arm stuck to the bottom of my shoe. Busy with DC training, I was suitably perturbed by this unfortunate twist of events and desperate to have it resolved asap. 100% convinced this MUST be a warranty claim, off I go to CWC. I was met with shock, incredulity and even a degree of mirth as this was the first time (so they claimed) they’ve ever seen a crank arm broken in half. Note the Ultegra 6800 crank set is a “Hollotech” unit, with the crank arms construction consisting of a strong inner moulded metal construct with an (aluminium) outer plate (glued) to it. Anyway, after producing the required invoice, some explanation and convincing that it was not as the result of an accident, off the unit goes for a warranty claim. The supplier could not immediately find a replacement (175mm 53/39 tooth) unit and after an interminable 2 weeks, I threw my toys out the cot. Seeing Oom Chris in attendance, I off-loaded my irritation on him. Long story short, within a few minutes my bike was in the workshop (kudos) and a replacement unit was sourced from existing floor stock (kudos). Although they weren’t going to replace my blades, the outer plate were damaged and didn’t line up properly, so blades were sourced from new stock (kudos) and off I went with a FREE bike stand (kudos) and inner tube (kudos) as ‘gifts’ to lessen the frustration. Roll on another a year and a few months and I noticed a squeaky noise while pedaling. On investigation, I discovered the outer drive crank arm plate separated from the inner causing a squealing racket. Off to CWC I go again and here’s where the process became a bit complicated. I did not have any receipt anymore and on their system they only had details related to the original purchase. Although I explained the whole sequence of events, they could not find any reference to the replacement unit. Stuck. What the hell. What now. Just before giving up, them desperately trying to make me not feel like I’m trying to pull a fast one on them, along come Junior. He has one look at me and recalls the whole incident of months back related to the original crank claim. System is searched once again using criteria he provided and thank the Lord almighty they found the details. Junior requested I give them a few days to resolve, gratefully agreed to. Week later I got my SMS from CWC confirming they received my replacement. I can collect. The incident of breaking a crank caused me to do some research and although Shimano has not (to my knowledge) recalled these Hollowtech Ultegra 6800 units manufactured around 2015/16, the unit’s since been replaced. Interestingly enough on the upgrade Shimano Ultegra R8000 unit, the drive side crank arm is noticeably thicker, and the crank unit weighs a few grams more that the old. Why thicker and heavier? In cycling, the thicker is not unusual, but upgrades being heavier, I think are. So … I assume they had sufficient claims as it does not take much research to see plenty comments worldwide related to these type breaks. Collecting bike from CWC, I found the supplier replaced the original FC6800 53/39 with a R8000 52/36 (semi compact) unit. I’ve been toying with the idea of going semi compact, so saw this as a sign from above, and gleefully accepted. Very grateful to the two ladies at the CWC warranty claim desk for keeping me informed every step of the way, and being so patient with a frustrated customer knowing the truth but having difficulty proving it. And … to Junior for his great memory. Kudos guys. Lessons learnt: Guys using those older FC6800 units just be careful out there; can cause a real mess if it breaks at the wrong time. And … always make sure you keep all your paperwork, especially proof of history after claims, repairs, returns, replacements or warranty, etc. to smooth the process in case of further problems.