Spin Doctor Tech Tip – Shimano Dura-Ace Di2 Electronic Shift System

So you’ve won the lottery and your first big purchase is Shimano’s new electronic Dura-Ace Di2 drivetrain.

Before you install it, BE ADVISED that your ego may be put in jeopardy. Yes, the new Di2 components are so slick that your bike, once Di2 adorned, will be smarter than you. Push a button and you have perfect shifts every time. The front derailleur will automatically trim itself to eliminate cross chain rubbing, and the rear derailleur disconnects its motor when you lay the bike down. The system will even tell you when the battery is low or if there’s a malfunction. Plus the battery lasts 1000 KM and will recharge in only 90 minutes.

Like we said, this stuff is SWEET!

Even better, Dura-Ace Di2 meets the “clock on the VCR” standard. If you can program the clock on your VCR, installation of Di2 will be a snap. The components come with good, clear installation and set-up instructions plus Shimano has an even better online tutorial, http://di2certified.shimano.com. That site features both a how-to video and an interactive installation and operation lesson.

But there are a few small subtleties that, if missed, can short circuit Di2’s marvelous performance.

Be aware of these issues:

• Do not touch the cable connector terminal/contacts. The system is great but can malfunction if the contacts are fouled.

RD-7970 rear derailleur

• The RD-7970 rear derailleur will  accommodate cassette cogs as large as 27 teeth, no bigger. Do not be tempted to install the new Dura-Ace 7900 11-28 cassette; it will hang up. Read more of this post