So much for Dura-Ace

Cycling equipment can be expensive. The top of the range components are not cheap. Bikes fitted out with top of the range equipment have price tags competing with high end motor cycles.

Are they worth it?

Screen Shot 2019 09 24 at 7 21 15 AMScreen Shot 2019 09 24 at 7 20 56 AMMy recent experience with Shimano’s top of the range Dura-Ace crank-set suggests not. A base level Shimano crank set will set you back €82.90. The Dura-Ace version costs €419.00.

2019 09 22 13 31 422019 09 22 13 32 18The crank arm snapped while riding. There had been some warning signs that all was not well. Most recently, the crank arm had been catching the chain in the high gears. The replacement was already en route.

2019 09 22 13 30 362019 09 22 13 58 58An investigation of how things went wrong is revealing. To keep it light, the crank is a monocoque construction made up of a chassis and an outer shell which are welded together at various points.

2019 09 22 13 34 42At the heart of the design is a weld-point that joins the spider to a cap, which connects to the axle. The cap is pushed into the axle, like a cork. If they separate, the unit’s strength is compromised, and the crank will start to flex, and eventually breaks from metal fatigue.2019 09 22 13 33 06

A clue that this might be happening is when the crank starts to creak. In my case, the creaking disappeared. That’s the sign that the welding has separated, and the crank is on its last legs.

2019 09 22 13 36 522019 09 22 13 39 00The real surprise is that this weakness could be easily designed out. On the opposite crank there is a threaded bolt that is used to tighten the left crank in place. A similar bolt on the right crank would ensure that the two components making up the right crank couldn’t separate. Yes, it would need to be checked for tightness every now and then, but it would be a better construction.

Shimano obviously thinks that some cyclists wouldn’t bother to check.

At least give us a choice.

This is clearly a design flaw. In my small circle of cycling friends. it’s happened to two others. There are plenty of complaints on the web. Shimano won’t do anything while their products remain so popular.

Perhaps a boycott will adjust their thinking.