Triathlon hasn’t benefitted much from many of the major cycling innovations over the years. STI was the biggest leap in recent memory and if you have been running a full TT setup then STI didn’t do anything for you at all. That is until Di2 came along. Shimano’s electronic shifting quickly changed the long held perceptions that such a system was doomed to join the scrapheap along with earlier iterations. Di2 has proven to be both reliable and accurate virtually since day 1. It has even managed to convert many a crusty old luddite, as it seemed many who said they didn’t “need” Di2 were reticent to return to mechanical once they had tested Di2.
Di2 has allowed greater flexibility in shifting options for TT/Tri setups with the major benefit being the ability to shift while the hands are on the bullhorns for climbing or braking. It can also make bikes a bit easier to travel with and can even make minor adjustments something that most can accomplish without getting a finger dirty.
So what is next? Well, I suppose that is the million dollar question. If you had said 10 years ago that electronic shifting bikes would be common place and readily affordable you would have been thought of as a bit loopy. So where we may be in another years is anyone’s guess, but a little gadget like the D-Fly may well prove to be a gateway to that future.
The D-Fly (or as it is affectionately known at Shimano the SM-EWW01) is an innocuous piece of kit, it is tiny at 38mm long, 25mm wide, 12.5mm in height, and adds just 8 grams to the drivetrain including the additional cable . Currently its job is to send out information, namely gear position and battery levels, to a head unit for you to see. Now when I first took delivery of the D-Fly I was concerned it would have a limited audience as only the Pro-Scio head unit, the Garmin 1000 and the Magellan Cyclo 505 were able to “see” it, and to be perfectly honest I didn’t know many triathletes that were using these types of head units. But around Christmas time Garmin released a big Firmware update that brought D-Fly functionality to both the 510 and 810 head units which now means more users have access to what the D-Fly has to offer.
So what does it offer?
Well in a nutshell it allows you to display gear data and battery usage on a compatible head unit. As we have become accustomed to with most, if not, all things Shimano it works well, is simple and effective. The D-Fly is compatible with the E-tube Di2 systems, being the Dura-Ace 9070, Ultegra 6870 Di2 and Ultegra 6770. The unit simply plugs into the Di2 wiring at any point, although the rear stay or under the stem seem to be the favoured positions. It is a great idea to ensure your Di2 is running the latest firmware before starting, but then it’s just a matter of clipping it on, plugging it in (with an optional extra cable) and then getting your head unit to find it like another ANT device.
Gear Display on a Pro Scio
Large format display on Garmin 510
Smaller format display on Garmin 510
So then it’s a matter of how much value you put in the ability to be able to visually check your current gearing. For some this can be an essential training tool, for some a convenience, for it may just be a neat novelty and others may not see the need. It is also pretty neat to be able to get a quick visual on your Di2 battery charge level, but in all honesty all that has done is to crystallise just how slowly the Di2 battery discharges.
Currently, although these few head units give you the ability to see the D-Fly data, there is nothing in their software to allow you to view this data which may be the kicker for some data nerds. But fear not! There is a site called di2stats.com that allows you to upload your files (in Garmin’s case a .fit file) and get lots of cool stats and funky coloured graphs. Nerd heaven!!
Some screenshots from recent ride showing just some of the info available from di2stats.com
The D-Fly is reportedly also compatible with Shimano’s CM-1000 Sport Camera, but until I can get my hands on one of those I will have to take their word for it.
The other thing on offer now is "possibilities". Now that third party items are able to read the Di2 data the mind bogles as to what uses may be found for this information.
So is it worth the $125 (plus the cost of a cable)? Well, if you already have Di2 and a compatible head unit, then why not spend a few more $$ and get the absolute most out of it. If you are a stats person, you can play with di2stats.com and go nuts, or if you like to check your gearing but don’t like trying to look down while riding then plug in, turn on and prepare for analysis paralysis.