Originally Posted by
oldacura
When I decided to go to electronic shifting on our new tandem, I automatically went with Ultegra Di2. I never considered SRAM.
Now with most everything, I assume there are advantages & disadvantages to each. Is there a thread on the tandem forum that makes a comparison (particularly with respect to tandem application)?
I have Dura-Ace Di2 on my single while my wife has eTap on hers.
We are currently having a tandem built with Di2.
My impressions:
Shifting performance is excellant with both, though the SRAM drivetrain is noisier.
With the announcement of the wide-range WiFli derailleur for eTap, specified rear cassette ranges is now identical vs. Ultegra Di2. Specified chainring sizes have always been identical.
There's a healthy and growing experience base with workable cassettes outside the specified range for Di2 (11-36 or 11-40 using Wolf Tooth or other products), but eTap is too new. The only datapoint I know of is a user who is successfull using a 11-32 cassette with a stock Red eTap deraillur (Not WiFli version).
Minor hassle with eTap on need to disconnect batteries prior to flying or driving the bike somewhere to avoid battery draindown. Not a big deal in my book.
Di2 seatpost battery replacement (if ever necessary) is a bit of hassle compared to simple battery replacement in eTap.
Battery life with either system is a non issue unless you are a real mega-miler.
Additional hardware required for wireless communication between Di2 and Garmins (or similar). No hardware necessary for eTap.
Di2 is relatively mature product (3rd iteration of Dura-Ace, 2nd iteration of Ultegra, 1st iteration of XTR), eTap will likely be rolling out new products to fill different niches for some time.
Just my random thoughts....