merlinextraligh

fewer wires.

merlinextraligh

Personally, I think we should be going the opposite direction. Everything wired into one unit.

Garmin, electronic shifting, power meter, lights (as an option) all run off of one battery.

I think Shimano is missing an opportunity not putting out a fully integrated set up, with computer, power meter, shifting all rolled into one.

Typical Di2 setup has the junction box under the stem. Just make the junction box the mount for the GPS, and you're not even adding a wire, and now you've got one battery for the whole friggin bike to charge, instead of two shifter batteries, two derailleur batteries, power meter battery, garmin battery to charge.

I'd definitely put up with a couple of wires in exchange for one battery for the whole bike.

GlennR

No wires.

GlennR

Single point of failure, if it goes, you're almost walking home.

Shifter batteries are good for a year, actually I spoke to the Sram rep and he said the real life is much longer than advertised. So just add it to your winter maint along with new chain, new brake pads and new cleats.

Derailleur batteries are interchangeable so if for some reason you forget for a month to recharge them you can always move the front to the rear since the front is used so much less.

merlinextraligh

Are Di2 batteries failing often?

And seriously, if you did have to ride without GPS or power data that is almost walking?

If you forget to charge it, Di2 already accomplishes by software, what the 2 separate batteries do with SRAM. As the battery runs down, you lose front shifting first, but you still can shift the rear.



So functionally, you'd be in the same place you would be with SRAM.

gregf83 

They can only give you a rough estimate, not a precise number. Distance or ride time are both reasonable metrics as most people track or have a feel for how far or how long they ride. I know how far I ride in a month but have no idea how many shifts I make per hour or km.

merlinextraligh

And does anyone else think the battery on the SRAM RD is friggin ugly? Particularly compared to a seatpost battery for Di2.

GlennR

Ever find the battery on your 2 year old cell phone doesn't last as long as when new?

GlennR

Either you prefer Sram or you prefer Shimano, i doubt the cosmetics will cause you to change your mind.

rm -rf

I like the interchangeable battery design. And the battery latch looks sturdy and easy to use.

Battery capacity
1000 km / 600 miles is about half of the usual Di2 mileage per charge reports from users.

But I shift my Di2 all the time, and typically only get about 600 miles from a charge. (After a series of rides on very hilly rolling terrain, I needed a recharge after 400 miles.) And now I'm charging without waiting long in the "blinking green" status of 25-50% charge, after I ran out of charge on a ride. I like being able to see the green battery status light on the junction box while I'm riding.

Electronic shifting is so fast and easy. I shift way more often than on my older bike, often shifting the rear for just a couple of pedal strokes before shifting again, and shifting the front ring on quite small hills.

So the Sram riders would probably just recharge once a week or every two weeks, instead of watching the battery status. And they have to press a button on the derailleur to see the light.

Front derailleur
After the last Sram electronic thread, I was paying attention to my front shifting. Maybe once every other ride, I shift the front chainring, but it's already in that ring, and nothing happens. I just lose track of which ring I'm in occasionally. I think it's in cross-chained situations, where it's not obvious from the bike's mph speed.

But the Sram method would change it to the other, wrong, ring. Well, the rider could just shift it back again. It'll be interesting to see how often this happens in real life.

rpenmanparker 

Not so. SRAM will give you choice. You could at any time switch the batteries to put the good one in the front and get on the ring you want. With DI2 when it's gone, it's gone. And what if you don't like where you are in front when that happens?

PepeM

Ask Thibaut Pinot.

JohnJ80

I have a Di2 bike and like electric shifting a lot.

I'm going to keep an eye on the eTap stuff. It would be a good way to convert a mechanical bike to electrics without that taping the wires to the down tube scheme that Shimano has.

J.

merlinextraligh

Actually, I own both SRAM Red and Dura Ace Di2. Each has their place.

I like that SRAM is thinking outside of a cable based paradigm in designing its electronic shifters.

I'm not sold on wireless, and multiple batteries.

merlinextraligh

You've got to be pretty inattentive to run out of battery power with Di2. When it's running low, you've still got several rides before it gets to the point it won't shift the front, and you could still ride it, with just the rear shifting for a good number of shifts after that.

I ran the battery down once to where the front stopped shifting. (when first put it on, and apparently it wasn't fully charged out of the box) Did a 40 mile group ride after that with no indication that it was going to stop shifting on the rear anytime soon.

There's just no real worry, you won't be able to shift with Di2, hence no real advantage of being able to swap batteries with Sram.

WalksOn2Wheels

Man, I can just feel myself turning into a retrogrouch. I'm scared of what my cycling future looks like in about 10 years...

But yeah, if I were going to go electric right now, I'm pretty sure I would go Shimano. While I do see eTap as a unique innovation, I can't understand the compromise of fiddling with 4 separate batteries just because I don't like wires. Most bikes can take a really, really clean install of Di2 with minimal wires showing. And it's a one time install. From then on out, it's one battery to charge/mess with. Plus, as has been noted, you get early warnings that the battery is low whereas the eTap requires you to make a point to check it out or suddenly find out that one of your two derailleurs aren't shifting.

But hey, this is a free market. People will like what people like. For some, the additional battery maintenance might be worth it simply for the way the paddle shifting works. For some, it will simply come down to SRAM vs. Shimano. I'm certainly interested to see how it goes in the real world once it hits the market.

bonz50

one of the things that wireless shifting opens up to is being able to connect to a head unit (like garmin) and use cadence, speed, gear selection, power, etc and will be able to automatically be able to shift to keep you in your cadence without having to think about it.... this is definitely out of the box thinking and if SRAM can integrate with Garmin (i've read they are working on it) it will be an interesting advance in cycling. you'll never be in the 'wrong' gear based on your desired settings/limits....

Jarrett2

You don't get to play innocent on the forum anymore, especially in SRAM threads

GuitarBob

You're probably posing this because you imagine it to be nearly zero. The Peleton article reports "...can save up to 100 grams." Yes, that seems like a lot to me too, but there you have it.

merlinextraligh

Nothing unique to SRAM's wireless approach there. Di2 already integrates with Garmin. Admittedly, it doesn't take much advantage of the connection, just displaying data regarding gear ratios, shifts, and battery status, but the connection is already there.

Jarrett2

I wonder how cold affects all the batteries. I ride down into the mid 30's and at that point I find all of my battery operated devices suddenly have a much shorter functional cycle at those temps. I've had my power meter drop out on me, various lights cut out in the middle of a ride, speed sensors, cadence sensors as well.

None of that really makes a substantial impact on my ride, but if my shifting suddenly stopped on a 35 degree ride, that could be a real problem.

BoSoxYacht

I don't "imagine" it to be nearly zero, but as a person that works with CF, building and repairing bicycle frames, I can tell you it's far less than 100 grams.

JohnJ80

Li-ion is pretty much fine until you go a lot colder and is actually the near the best of the readily available rechargeable battery chemistries for cold performance. NiMH is much more cold sensitive.

I'm up here in MN and I routinely ride my Di2 bike in the cold. Every ride last week was at night and the temps where hitting down to 35F give or take a few degrees. I didn't notice any difference in battery capacity at all. I pretty much wind up charging my Di2 battery about every 1000 miles or so regardless. Even then, I've not seen it get lower than 40%. I would say it is has not been an issue for me.

J.

HazeT

where did I claim it is a problem?

Jarrett2

That's good to hear. I hope SRAM's version is similar in that regard.