Let's take a look at the new drivetrain first. New Alfine 11 Di2 hub with motor unit, with new rear 28T Gates sprocket and new 115T Gates CenterTrack belt.
Before: 113T red colour belt, with Chain Guard on the mechanical Alfine 11 hub
After: New Alfine 11 Di2 hub, with Chain Guard removed. The belt and Motor Unit are able to fit within the limited space with the use of the special 28T sprocket.
MU-S705 Motor Unit installed to activate the electronic shifting. Di2 wire connects to the port at the bottom.
Di2 wire runs discreetly behind the right side chain stay to Junction B
Using the Di2 wire tape to position the wire neatly
Using long chain ring bolts and spacers to adjust the position of the front chain ring, in order to get a straight chain line.
A straight chain line is necessary to prevent noise and premature wear of the belt
Drivetrain installed! Front 42T and rear 28T.
New gear ratios of this Alfine 11 setup. Due to the larger 28T sprocket (previously 24T), the whole gear range has been lowered.
With the drivetrain installed, the focus now moves to the braking system. Compared to the braking system, the drivetrain set up is easy. The reason is that the brake system needs to be assembled from scratch, as the brake caliper and brake levers are not pre-assembled and pre-bled at the factory like most flat handlebar hydraulic brakes.
Bleeding the hydraulic disc brakes is new to me as I have not worked on hydraulic brakes before. However, with the help of the ST-R785 Dealer's Manual and some help from friends, I managed to bleed the brakes properly. Prior to this bike, I also practised bleeding the hydraulic brakes on another bike. A good hydraulic disc brake bleeding kit is also necessary. The process is rather tedious the first time round, but once you get the hang of it, it gets easier.
Dealer's Manual for ST-R785
Left side of ST-R785. Only used as a brake lever with no shifting function on this bike.
Right side of ST-R785. The two shifting switches are used to shift up and down the 11 gears.
Mounted on the compact road drop bar. The hood is taller than normal road shifters, but not an issue.
80mm stem mounted
Alfine digital display SC-S705 mounted as neatly as possible.
Accessories mounted on the handlebar. Limited space due to the narrower drop bar compared to a normal flat handlebar.
New bar tape! Trying out this silicone bar tape for the first time. No adhesive means it can be reused many times, while it is also water resistant and non-slip for wet weather usage.
Nice grippy, rubbery texture, quite comfortable too.
New handlebar setup, with road hydraulic shifters.
Di2 wire between the digital display (Junction A) and Junction B is routed neatly along the rear brake hose. Shown behind is the DIY steering stabilizer.
Battery mounted on the downtube, below the bottle cage. Junction B is fixed behind the seat tube with strong mounting tape + cable tie. Tried and tested on the Dahon MuEX and Wheelsport mini velo.
Front hydraulic disc brake caliper, comes with Ice-Tech brake pads.
Not as sleek looking as the new Flat Mount standard, but works just as well.
Rear hydraulic disc brake caliper
Picture showing the new drivetrain. Clean appearance and maintenance free.
Full view of the bike. Converted from flat handlebar to drop bar setup.
An all-weather drop bar commuting bike, which is coincidentally also a great touring bike.
This project has finally been completed, and it was not an easy project. Although I had experience with setting up the Di2 system and the Gates belt drive system, installing the hydraulic disc brakes were new to me. There were no major issues or difficulties with this modification, just that it is tedious due to the many components that were changed.
At this point, the speedometer reads 2700 km, which is the distance traveled on the previous mechanical Alfine 11 hub. In about 1000km, it will be time to service the new Alfine 11 Di2 hub by changing out the oil inside the hub.