Begin with the chain on the smallest cog. Relax the cable tension completely using the cable barrel adjuster. Place a hand on the derailleur body to feel for any lateral motion, and select one screw to turn one full turn clockwise and then counter-clockwise. If you felt motion in the derailleur, this is the “L” screw.
A modern Di2 battery is said to last between 2500 and 5000 kilometers. This depends a bit on how often you shift and also your shifting style.
Ultegra is a groupset designed to be used for a variety of riding styles. To this end, Ultegra can now accommodate a 34t cassette, whereas Dura-Ace tops out at a 30t. Similarly, the Ultegra rim brakes are heavier because they have to be larger to accommodate 28mm tyres, which means more materials and extra weight.
Waterproof. Shimano reckon Ultegra Di2 is completely waterproof. They say it'll be fine even if you're driving along the motorway in the rain with your bike attached to a rack.
It's still early days but already the Dura-Ace Di2 – which stands for digital integrated intelligence – is receiving favorable reviews, with talk of significantly slicker, cleaner gear changes and one expert opinion describing the electronic component series as “revolutionary”.
It seems to be a bit of a hidden feature for most cyclists that even some bike shops forget. Shimano's Di2 electronic drivetrain has a protection mode that it defaults to when it thinks there has been a crash. This leaves the derailleur in a state of no response when trying to cycle through the gears.
All of the Ultegra parts, particularly the front and rear derailleurs, are noticeably heavier than their Dura Ace counterparts – 263 grams, about half a pound. This being said, the Ultegra Di2 is only 80 grams heavier than the mechanical Ultegra group, so the weight penalty for going to electronic shifting is minor.
An Ultegra Di2 front derailleur will set you back about $560, while Dura-Ace Di2 is about $780. Ultegra Di2 shifters are $445; Dura-Ace Di2 are nearly double that at $930. The rear derailleur sees a similar difference, with the UDi2 at $340 and DADi2 at $740. The UDi2 wiring harness is about $15 cheaper than Dura-Ace.
Shimano Dura-Ace 9150 Di2 Synchro Shift explained
So called 'fully-syncro' shifting means that a single shift lever takes control of the entire drivetrain (you can chose which buttons make the necessary operations). In this way you're simply selecting either an easier gear or a harder gear.Generally a Di2 build consists of the following parts:
- Front Derailleur (optional)
- Rear Derailleur.
- Shifters / brake levers.
- Battery.
- Junction box A.
- Junction box B.
- About 4-6 Electric wires.
- Wireless Unit (optional)
Shimano: Free stroke is defined as stroke of the lever before the pads start touching the rotor. The free stroke screw simply changes the starting point of the master cylinder piston. Turn the screw out a bit and the master cylinder will start further out.
You need to use a 2.5mm Allen key to adjust this one. Turn the bolt clockwise to bring the lever closer. This done, you can work on the brake lever adjustment. Pull back the rubber covers on the hoods, and again use a 2.5mm Allen key, tuning it clockwise to reduce the reach.
