Thursday, December 18, 2014

Merida Scultura 5000 - Ultegra 6800 Crankset (Compact 50/34T)

Continuing from the previous post about the upgrade to Dura-Ace 9000 BB and chain, in this post I will write about the upgrade to the crankset.

The Merida Scultura 5000 (and many other 2014 Merida road bikes) come with the Shimano non-series 11 speed crankset, FC-RS500. This is an affordable 11 speed crankset that is quite a bit cheaper than the Ultegra or Shimano 105 cranksets. By using this lower cost non-series crankset, the bike OEMs will be able to lower the price of their bikes.

Stock crankset, the non-series Shimano 11 speed road crankset, FC-RS500.

11 speed compatible, and in compact gear combination of 50/34T.

The machined chainring cutouts and the black finishing is actually quite attractive, and makes it easy to match the appearance of almost any bike frame.

Weight of left crankarm + crank bolt is 249 grams.

Weight of right crankarm + chainrings is 546 grams.

Together, the FC-RS500 non-series crankset weighs 796 grams (some rounding off error).

Now, this non-series crankset actually performs quite well and I have no complaints about it. Shifting is fine and it also looks quite good. With a crankset weight of 796 grams it is actually not very heavy for this grade of crankset.

The Merida Scultura 5000 comes with some Ultegra 6800 components, and it is my wish to have a complete Ultegra 6800 groupset on the bike. This means swapping out some components for Ultegra 6800 components, and the crankset is one of them. One of the components which had already been changed to Ultegra is the cassette, which was upgraded a while ago.

By upgrading the crankset to the Ultegra 6800 crankset, the expected differences are lower weight, better shifting, stiffer crankset and better appearance.

Ultegra 6800 crankset!

Same compact 50/34T chainrings, length of 170mm.

One thing to note is that for newer cranksets (Dura-Ace 9000, Ultegra 6800 and Shimano 105 5800), the crank bolt is now longer than those on older cranksets. This is to improve the thread engagement of the crank bolt onto the spindle, so that there is less chance of it dropping off or stripping the thread. Another reason is to allow the left crankarm to be tightened onto the spindle even if a BB spacer is placed under the right side BB cup.

Same serration profile for old and new crank bolt

The new crank bolt on the right can be seen to have twice as many threads as the previous version.

One thing that I really like about this new Ultegra 6800 crankset is that it looks really good. The matte/glossy grey anodised finishing looks very high end, and I think it looks even better than the chrome + black finishing of the Dura-Ace 9000 crankset.

Another big difference is the 4 arm design, which is radically different from previous generations of 5 arm crank designs. At first it may seem weird if you are not used to it, but after seeing this 4 arm design for a couple of years, I actually find it quite special, and it helps to identify the groupset series on the bike.

Ultegra 6800 crankset with the iconic 4 arm design

11 speed compatible, also compact 50/34T chainrings. Both standard 53/39T and compact 50/34T cranksets share the same crankarm, with the same BCD.

Outer chainring is made of 2 parts bonded together, as you can see from the picture here. The outer layer with the chainring teeth is bonded to the inner layer which creates this hollow outer chainring.


Some shifting ramps and pins on the inside of the outer chainring to improve shifting.

34T inner chainring made of aluminium

The crankarm is also made of 2 pieces bonded together. In fact you can still see some sort of hardened epoxy oozing out near the 4 arm area.

Lots of codes and numbers for identifying the part and batch of this production

No I did not cut open my Ultegra crankarm. This cut-away sample is from the display at Shimano Cycling World, showing the hollow crankarm and its two piece crankarm construction.

Hollow crankarm of Dura-Ace 9000, with even thinner walls for lighter weight.

Left crankarm + crank bolt weighs 197 grams.

Right crankarm + chainrings weigh 480 grams.

Together, the full Ultegra 6800 compact crankset (170mm) weighs 677 grams.

The weight of the Ultegra 6800 crankset is 677 grams, while the non-series RS500 crankset weighs 796 grams. This gives a weight reduction of 119 grams by changing the crankset.

Previously, I had also changed out the BB from the Tiagra BB to the Dura-Ace 9000 BB, which saved 26 grams. Together, changing the crankset and BB from RS500 + Tiagra BB to the new Ultegra 6800 crankset + Dura-Ace 9000 BB saved 145 grams.

Comparing the appearance of the non-series RS500 crankset with the Ultegra 6800 crankset.


Yet another picture of the great looking Ultegra 6800 crankset

Recent new components that have been installed on the Merida road bike. 

Installed the Ultegra crankset into the new Dura-Ace 9000 BB

Another look at the Ultegra crankset and Dura-Ace BB

No need to re-adjust the FD position, as the size of the chainring is still the same.

Re-installed my favourite PD-A530 SPD pedals onto the new Ultegra crankset

View of the drivetrain side of the crankset

Full view of the bike with the new Ultegra 6800 crankset!

I think the new crankset matches the bike frame and the rest of the components really well. The new Ultegra crankset is also lower in weight than the original RS500 crankset. As for shifting performance, it feels the same before and after the change. For a comparison with the previous generation of Ultegra 6700 10 speed crankset, you can check out this post.

On the other hand, the improved stiffness of the crankarm can be felt when I perform a static loading test. How I do it is to point the crankarm downwards at the 6 o'clock position, and step on the pedal to provide a loading force. The crankarm will deflect inwards and this can be seen quite easily if there is any flex.

When I perform this test on the RS500 crankset, there is a noticeable deflection of a few millimeters inwards. When I tried it on the Ultegra 6800 crankset, there is almost no deflection at all. This difference in stiffness can be seen visually and also felt through the feet.

So far, with the weight reduction from the Selle Italia SLR Kit Carbonio Flow saddle (save 215 grams) and also from this new crankset and BB (save 145 grams), there is a weight saving of 360 grams over the stock set up.

There are still some components which are not of the Ultegra groupset yet, so there are more changes to come!

Saturday, December 13, 2014

Merida Scultura 5000 - Dura-Ace 9000 Bottom Bracket and Chain

More upgrades for the Merida road bike! I have enjoyed riding this road bike, and also look forward to upgrading some of the components. Most of the stock components work well and there is actually no strong reason to upgrade them.

However, I do like to upgrade components for the sake of upgrading. During the upgrading process, I can learn more about the component and also compare the old and new components to see the differences. A bonus side effect is that it can improve the performance, enhance the appearance of the bike and hopefully reduce the weight as well.

Today, the upgrade will be for the Bottom Bracket (BB) and the chain. These are relatively cheap components of the drivetrain, but they are definitely critical. Without the BB or chain, there will be no drivetrain.

The Merida Scultura 5000 comes stock with a Shimano Tiagra 4600 bottom bracket, which is a no-frills Hollowtech II road BB. There is nothing wrong with it, but I would like to change it for a more high end BB.

This road bike comes with mostly Ultegra components, but the BB is not one of them. In this case, I will upgrade the BB to the latest Dura-Ace 9000 BB. The BB is the most affordable Dura-Ace component, and it is smaller in size, more lightweight and has 50% less rotational resistance than the previous Dura-Ace 7900 generation.

Dura-Ace 9000 Bottom Bracket, 68mm.

Due to the smaller outside diameter of the newer BB bearing cups. an adapter is needed if you want to use standard Hollowtech II tools.

This resin adaptor comes packaged together with the Dura-Ace BB.

Comparing the Tiagra BB with the Dura-Ace BB. The outside diameter is an obvious difference. The inside diameter for the crank spindle is the same 24mm, so it can be used for any road Hollowtech II cranksets.

Same length, but different bearing sizes and diameter.

Tiagra SM-BB4600 weighs 90 grams...

...while the new Dura-Ace 9000 BB weighs less at 64 grams. A small weight saving of 26 grams.

Crankset and old BB already removed, and BB shell threads cleaned in preparation for installation of new BB.

Holes inside the BB shell. This will allow internal routing of cables if required. The RD cable is actually routed above this opening in the BB shell, and can be accessed through the holes you see in this picture.

The standard Hollowtech II BB tool is too big for the smaller Dura-Ace 9000 BB cups

Use the included BB adapter to change the outside diameter of the BB cup to the standard size...

...and the standard BB tool will fit nicely! Installation is straightforward without any problems.

New Dura-Ace BB looks really small compared to the large BB shell on the frame

New Dura-Ace 9000 BB is ready to receive a crankset!

Note:
There are currently 3 different bearing cup sizes for road Hollowtech II BB. There is the standard size which is used for Dura-Ace 7800/7900, Ultegra 6600/6700, Shimano 105 5600/5700. This can be installed or removed using the standard Hollowtech II BB tool.

Then there is the Dura-Ace 9000 size, which has the smallest bearing cups as you can see here. It comes with a resin adapter so that you can use the standard tool for installation or removal.

Now, there is also a third size, which is used for the new Ultegra 6800 and Shimano 105 5800. This BB model is SM-BBR60. It is larger than the Dura-Ace 9000 BB, and yet is smaller than the previous generation of BB. Therefore it also comes with its own adaptor for compatibility with standard Hollowtech II BB tools.

Other than the BB, I also took the opportunity to change the chain. The chain that came stock with the Merida bike is a Shimano 105 5800 11 speed chain. No problema with it, but I would like to use a Dura-Ace chain due to its superior rust resistance. I am also using the 10 speed Dura-Ace 7900 chain on my other folding bikes, the Dahon Boardwalk, Dahon Vitesse and Dahon MuEX.

Dura-Ace 9000 11 speed chain. Not too expensive if you get it online.

Just weighing it for reference. Not expecting to get any weight savings from changing the chain.

Used a KMC MissingLink to join this new chain together, without using the chain pin.

For 11 speed chains, the KMC MissingLink cannot be reused (as recommended), and it is too tight to remove by hand. This eliminates a lot of the advantages of having a KMC MissingLink, as it means that it cannot be removed as easily, and it should not be removed for chain cleaning (unless you are willing to replace the MissingLink with a new one).

Still, I decided to use the MissingLink as it allows the chain to be joined or disconnected easily (with the use of the MissingLink pliers), and it also gives a good reference point for lubing the chain.

New Dura-Ace 9000 chain. Hollow chain pins are there to give a little bit of weight reduction.

With a gold coloured KMC MissingLink, it is easily visible on the chain. A silver version is also available.

New chain on the bike...guess what upgrade is coming up next?

After installing the new BB and chain, the bike upgrade is well underway! My aim is to give the bike a full Ultegra groupset, and there are still a couple of parts that are not Ultegra grade yet. More to come in the next few posts!