Thursday, January 11, 2018

Shimano Dura-Ace Road Hydraulic Mechanical Shifter ST-R9120

Road hydraulic disc has been gaining popularity in the recent years. With improved braking performance and modulation, it is no wonder that more riders are choosing to go with hydraulic disc brakes instead of conventional caliper rim brakes.

As such, the types of road shifters used must also evolve to match the new braking system. There are two types of shifting systems: Mechanical shifting which uses steel inner cables to activate the front and rear derailleurs, and electronic shifting that uses electrical signals to activate the motors in the front and rear electronic derailleurs.

Today's post will be about mechanical shifting together with hydraulic disc brakes. For such a road shifter, it will need to incorporate the shifting mechanism as well as the hydraulic brake mechanism within the road shifter. This is a big challenge as these parts take up space and it is hard to squeeze both of them into the limited space of the road shifter.

For Shimano, the first generation of such a shifter is the non series ST-RS685, more details which can be found at this post created two years ago. Now, there is an official Dura-Ace version of such a shifter, which has a model number of ST-R9120. This is the second generation design, therefore it will be more refined and probably with significant improvements.

Let's take a look at this Dura-Ace ST-R9120 road shifter, which is used for mechanical shifting and hydraulic disc brakes. A detailed comparison with the first generation ST-RS685 will be made later in a separate post.

ST-R9120, weighs 265 grams for one side. A pair will thus weigh 530 grams, which is significantly heavier than the rim brake version which is 365 grams per pair.

With the rubber hood stripped off, the Bracket of the road shifter can be seen clearly. This is the "outside" which is facing the outside of the bicycle.

The "inside" of the shifter.

The biggest difference from the first generation ST-RS685 is that the Bracket material has been changed from aluminium to resin for weight savings.

The front part of the shifter is where the reservoir is located, with the "piping" for the hydraulic fluid machined within the resin Bracket. Bleeding port is located on top.

The rear of the shifter where the hydraulic hose will be connected. Note that this thread is a special M9x1.25 size! Not the usual M8 x 0.75 thread. Clamp band is made of titanium.

Rubber damper for the lever is inserted from the side. Other cutouts are there to secure the rubber hood onto the Bracket.

Similar to other mechanical shifters, the inner cable is inserted from the side. Bracket is made of nylon with a mix of carbon fibre for strength. Silver bolt on top of the Bracket is for adjusting the free stroke, although the adjustment range is very small.

Lever mechanism is similar to other road shifters, while the steel plates now have a black surface treatment instead of silver colour.

Bolt in the centre is used to adjust the reach of the lever, which is separate from the free stroke adjustment.

Without dismantling the shifter any further, this is all that can be seen from the outside. On its own, it is quite amazing that both the shifting mechanism and the hydraulic mechanism has been squeezed into this road shifter without making it too bulky. In a separate post, this new ST-R9120 will be compared to the ST-RS685 to see what has been changed from the first generation.

Monday, January 1, 2018

Canyon Endurace: Dura-Ace Road Hydraulic Di2 Shifter ST-R9170

There are 4 types of road shifters in the new Dura-Ace R9100 series. With two types of shifting (mechanical or electronic), and two types of braking (rim or hydraulic brakes), it gives 4 different combinations, which will suit anyone regardless of your shifting or braking preference.

The most premium combination is the electronic shifting, hydraulic disc brake version, which has the model number ST-R9170. Combining Di2 shifting with road hydraulic disc, it features effortless shifting and braking. Also, it is the only version not to use any steel inner cable for shifting or braking. Replacing the shifter inner cable is the Di2 electrical wire, while replacing the brake inner cable is the hydraulic brake hose.

These shifters will be replacing the non series ST-R785 that came with the Canyon Endurace road bike. The ST-R785 is the first generation of Di2 shifting/hydraulic braking road shifter, while this Dura-Ace ST-R9170 is the second generation. My plan all along was to upgrade the groupset to a full Dura-Ace groupset, from the stock Ultegra Di2 6870 groupset that came with the bike.

Handsome looking Dura-Ace ST-R9170 road shifters, with a very high quality finishing on the levers.

Another view of the new shifters. The lever shape has been subtly refined from previous generations.

Overall shifter shape is very similar to other shifters in the same Dura-Ace R9100 series, which is done by totally redesigning the shifter.

Another overall view of the ST-R9170

Due to the resin Bracket construction, the shifter weighs only 160 grams per side, giving a total weight of 320 grams per pair. This is very lightweight!

The Di2 shifter buttons have been increased in size compared to older Di2 shifters. The clicking feeling has also been enhanced for a better tactile feel.

Electronic button unit looks to be quite well integrated into the lever.

This textured area at the top of the hood hides a button underneath! This button can be programmed to perform shifting functions or control other devices such as the Garmin computer.

Hydraulic hose attaches to the rear of the shifter. Titanium clamp band for weight savings.

From the outside, the shifter looks very ordinary, as the rubber hood hides all the interesting bits underneath. However, once the rubber hood is removed, it looks much more interesting!

With the hood removed, the Bracket design can now be seen. The small box is where the Di2 wire will connect to. This box is linked to the top button by a wire...

...while the top button is linked to the shifter buttons below by another wire running through the area shown above.

Bleeding this hydraulic shifter requires an adapter (included) to enable the standard bleeding cup to reach the bleeding port on the shifter. This is because the bleeding port on the shifter is located on top, in a recessed area.

Slot on side of Bracket to guide the cam of the hydraulic piston, for a Servo-wave effect.

One thing you notice is how many ribs are used to strengthen the Bracket and yet keep it lightweight! This is only feasible as a molded resin bracket (nylon + carbon fibre) is used. These ribs also make removing and replacing the rubber hood very difficult.

Located at the bottom of the shifter are the free stroke adjustment bolt (on right) and the lever reach adjustment bolt (on left).

Hydraulic piston slides along the internal bore of the Bracket when the brake lever is activated.

A quick comparison of the new Dura-Ace ST-R9170 with the older ST-R785. The lever shape is noticeably different, with the Dura-Ace lever having the same curved shape as the mechanical road shifters.

The new Dura-Ace shifter is also lower in height, which makes the new shifter look much smaller in size. This is possible only due to a new hydraulic brake design.

In a separate post, the ST-R9170 and the ST-R785 will be compared in greater detail. From what I can see, the main differences by making this upgrade is a slimmer looking shifter and also lighter weight. Ergonomics will be similar to other road shifters with Di2 or mechanical shifting, while the tactile feeling of the Di2 buttons will be improved.

Wednesday, December 27, 2017

Dahon MuEX: 1x11 Drivetrain - Installation

Finally, after preparing the 11-32T 11 speed cassette, the short cage Ultegra Di2 rear derailleur, and the front single Ultegra 6800 crankset with Wolf Tooth 48T chainring, it is time to assemble all these new components to the Dahon MuEX!

It was already set up with a 2x10 speed Ultegra/XTR Di2 system, so there is no need to start from scratch. The advantage of having a Di2 setup is that it is modular. So if you just need to upgrade the rear derailleur, just unplug and replace the rear derailleur, and you are done! No need to change the shifters or the Di2 wires.

In this case, since I am going from a front double to front single drivetrain, the front derailleur can be removed, along with the left side shifter. The new Di2 wiring layout is shown below.

New 1x11 speed Di2 wiring layout. No more front derailleur or left side shifter.

Once everything is connected, the Di2 setup box SM-PCE1 can be connected to the system to update all the Di2 components. This ensures that the latest firmware is used and all the components are compatible with one another.

Previously, when the Ultegra Di2 front derailleur was installed, a 2.5mm spacer had to be placed under the right side bottom bracket cup to prevent the crankarm from touching the front derailleur. Now, without the front derailleur, there is no need for this spacer.

Red 2.5mm spacer under the right side bottom bracket cup can be removed.

Ultegra 6800 crankset with Wolf Tooth 48T chainring installed! Looks really good with the red chainring bolts.

Close up look of the interface between the chainring and the crankarm.

Front derailleur removed!

Ultegra 6800 11-32T 11 speed cassette installed!

Special short cage edition Ultegra Di2 RD-6870 rear derailleur for 11-32T cassette. Very ample tire and ground clearance.

Chain path when in the rear low gear. Rear derailleur cage is not over stretched even though it is a short cage, because there is only one front chainring.

Good clearance between cage/chain with tire

Another view of the clearance.

Setting the chain to the rear top gear puts the chain in the smallest sprocket, closest to the frame. Still ample clearance between chain and frame.

Chain path when in the rear top gear. Rear derailleur cage is slightly extended to maintain some chain tension to minimize chain slap.

Another view of the Di2 rear derailleur on the cassette.

Handlebar gets tidied up a bit, without the left side shifter and the Di2 wire between the left side shifter and the display.

Now it is 11 speed as shown on the display! I love the digital gear display, like how I first tried it on the Dahon Boardwalk Di2.

The bell can be mounted at the left side handlebar area, inverted for a neater look. Activate the bell by pulling the bell lever with the index finger, similar to how a shifter is operated.

No interference between the bell and other parts when the handlebar is folded down

Sufficient clearance for the bell when the bike is folded

View of the folded Dahon MuEX 1x11 speed

For practical reasons, a kickstand is added to the bike despite the additional weight. Kickstand weighs about 157 grams.

Revised bike specifications, with the new 1x11 speed Di2 setup. Weight without pedals is reduced from 8.7 kg to 8.4 kg.

This setup has already been tested at the recent OCBC Cycle 2017, and there is no problem! The gear range is sufficient for climbing and also a bit of downslope pedaling. Of course, if you wish to pedal fast down the Sheares bridge slope, the gearing is not high enough. On all other days, this gearing is sufficient 99% of the time.

Gear shifting has been simplified, as there is just one shifter to shift across the 11 speeds on the rear cassette. The overall bike weight has also been reduced, due to the removal of the left shifter, front derailleur and second chainring. Even though the wide range cassette is slightly heavier, overall weight loss is still about 300 grams. Lastly, I get to utilize the components that were removed from the Canyon Endurace, using it to convert this Dahon bike to 11 speeds.