Dura-Ace Crankset Comparison: R9100 vs R9200 plus others

When Dura-Ace was refreshed from 11 speed to 12 speed, the crankset was changed as well. However, what I noticed was that the new R9200 crankset is actually heavier than the old R9100 crankset, and not by a small margin.

By comparing the individual parts of the crankset, we can see what are the parts that contributed more to this weight increase. Both of the cranksets have 50/34T chainrings, and are of 165 mm crank arm length.

At the end of this post, a brief comparison with even older Dura-Ace cranksets will be made. I kept some of these old parts of Dura-Ace crankset, just for collection's sake. For other comparisons, such as 9000 vs R9100, check this out.

Dura-Ace R9100 right crank arm, 303 grams.

R9200 right crankarm is 38 grams more, at 341 grams. Quite a substantial increase.

R9100 50T outer chain ring is 100 grams.

R9200 50T outer chain ring is slightly heavier at 107 grams.

Comparing the left crank arms! The surface finishing is quite similar, being gloss black.

R9100 on top, R9200 below. Different surface profile and also different fonts used for the Dura-Ace logo.

The gloss black surface treatment is really nice!

Rear of the left side crank arms look very similar in terms of shape, except for the brown seal ring on the R9200 crank arm. The production codes also show that they are manufactured more than 4 years apart.

The way these left crank arms are made is different. R9100 uses a two piece bonded construction, while the R9200 uses a one piece hollow forged design.

A bond line can be seen on the R9100 crank arm. R9200 is made in one piece, and has an additional "Science of Speed" logo printed at the end.

R9100 crank arm weighs 171 grams which is very light.

R9200 adds some weight, making it 197 grams. This is heavier than even the 105 crank arm of the previous R7000 generation.

Comparing the 3 main parts of the crankset, which are the right crank arm, left crank arm and the chain rings, here are the respective weight increases.

From R9100 to R9200:

Right crank arm: +38 grams

Left crank arm: +26 grams

Outer 50T chain ring: +7 grams

Total weight increase for these 3 parts is 71 grams, which is nearly all the weight increase from the R9100 (610 grams) to R9200 (682 grams).

Another interesting difference to note is the change of the crank arm fixing bolt. In the 9000 and R9100 generation, this bolt is quite long, to cover the hole on the spindle for the safety pin. The idea is for the long bolt to block water from passing through the spindle, which leads to the inside of the right crank arm.

However, in actual usage, the threads on the crank arm fixing bolt is not a watertight solution, and some water can still pass through. Therefore, for R9200, a plastic cap has been installed inside the spindle, to provide a waterproof barrier that seals the inside of the spindle and crank arm from external water ingress.

Plastic cap in spindle to prevent water from passing through the spindle. This means that the long crank arm fixing bolt cannot be used.

With the additional plastic cap in place, the longer crank arm fixing bolt can neither be used nor is necessary. Therefore, for R9200, the bolt has been changed back to the shorter type used in the earlier 7900 generation.

From left to right: Old type used on some aluminum spindles, 7900/R9200, and 9000/R9100 crank arm fixing bolts.

The older bolt has a smaller thread diameter because an aluminium spindle with thicker walls were used in some models. The other two has a bigger thread diameter, and differ in terms of length.

Another look at the three different types of plastic crank arm fixing bolts used in Shimano road cranksets.

The shorter crank arm fixing bolt weighs only 3 grams.

Longer crank arm fixing bolt weighs slightly more at 5 grams.

With this, the 1-to-1 comparison of R9100 and R9200 cranksets has been completed. In summary, the new R9200 crankset weighs more than the older R9100 crankset.

Next, I will do a brief comparison of even older Dura-Ace cranksets. With some luck and patience, I have some parts of 7800, 7900, 9000, R9100 and R9200 Dura-Ace cranksets. It is rare to be able to see them all in the same place as these components span over 20 years between them.

R9000 crank arm, 7900 crankset and R9100 crankset. Check out the individual links for more details.

From left to right: 7800, 7900, R9100 and R9200 left crank arms. I don't have the 9000 left crank arm.

The four different left crank arms for comparison. Newer R9100 and R9200 crank arms are noticeably chunkier.

With these comparisons, I learnt that a newer crankset is not always lighter in weight. In this case, the latest R9200 crankset is heavier due to additional material to make the crankset stronger and more durable.