Sram Electronic Groupo

[ergott]

It might be ok since 99% of PMs are already wireless and I don't hear a movement going away from that.

Big difference between missing data from a PM and not being able to shift when you want to.

[pdlpsher1]

It might be ok since 99% of PMs are already wireless and I don't hear a movement going away from that.

Big difference between missing data from a PM and not being able to shift when you want to.

My 'wired' Di2 is not 100% reliable either. Sometimes I press the button and nothing happens (it happens when I wear a thick glove and didn't press the button hard enough....the glove insulation takes away the feedback).

Missed shifts and dropped chains happen all the time on mechanical groups. So I would take a wireless electronic group over a mechanical group any day. Just my $0.02.

[eric]

if you hop freqs the guy will just blast a signal on all freqs

It appears that they're using DSS frequency hopping. That does make it more difficult for an attacker to jam the signal.
And the patent talks at length about the low level protocol which appears to send multiple commands (presumeably
in a way that allows detection of dups so the derailleur does not shift more cogs than the rider intended). That should make it more
difficult to intefere with.

A dude with a backpack (1000w takes a lot of batteries and a big amp) pointing a directional antenna at the riders would be kind of obvious.

That said I'd like to see hydraulic shifting too. Or if Shimano can get the weight of their next electronic system down to near Red levels.

I think that a wireless system could be made lighter than wired. The actuators and mechanicals are the same either way. Wlreless has 3 or 4 batteries (one per derailleur and one or two for the shifters). For wired the main battery has to have enough capacity for both derailleurs plus some extra so you don't run out. For wireless, each derailleur battery only has to have the capacity for its derailleur, plus about the same amount of extra capacity as the single battery. The CPUs etc are essentially weightless. So for wireless, the added weight is not in the battery itself but in the battery housings, and the shifter batteries. That should be lighter than the wires for a wired system.

The more I think about this and research it, the better it sounds. They could quite possibly get the weight significantly below mechanical Red.
Not having to run cables would be kind of cool. However I'm not sure I like how the shifter switches work. It seems more designed to get around patents than for usability.

[prendrefeu]

I just hope that they don't cease production on their RED level mechanical group.

It would be a sad day when the only build option is electronic and mechanical groups are no longer available.

Does your statement hold true even if the new electronic group could be lighter than the mechanical group? I've been on Di2 and I love it. I haven't made not even one derailleur adjustment since the upgrade. And with the new Di2 internal battery my group is lighter than the mechanical 9000.

Yes. While I am addicted to the weight savings wherever possible, I also have a strong desire for analog in my life and an absolute passion for that which is mechanical. I do not like the idea that repairing a bicycle would necessitate 'firmware updates', soldering wires, or other things which are not mechanical in nature. I do not like the idea that a human-powered machine is limited in function by the availability of an external source of power - whether replaceable or rechargeable .

I've used Di2. It was ok. I've used Record EPS. It was also ok.
I went back to RED.
(I have also used DA 9000 and the latest Ultegra... I would much rather have those systems than the electronic alternatives. They are fantastic.)

To each their own. I just hope that the mechanical groups are still developed and the consumer continues to have the option of choosing an updated, high-end mechanical group for their bicycle.

[showdown]

One thing that I was thinking about that seems problematic is that with a wireless system all the (complex) electronics reside in the respective components rather than in a central junction box. This seem troubling for me as rear derailleurs are quite vulnerable and take a lot of abuse (in racing), so too do shifters.

I would worry about the cost of replacing a complex component in the result of a crash etc... (Not that my Dura Ace Di2 system is exactly cheap)

I guess we'll all find out soon enough.

I'm pretty sure that high end mechanical systems will never go away and will continue to be refined and developed alongside electronic grouppos.

[eric]

Microprocessors, receiver chips and RAM chips are super cheap. The mechanical stuff like the actuator is much more expensive.
(the Atmel receiver chip mentioned in the patent is $2.80 in lots of 1000 from digikey, the CPU is about $3.40). Using the parts listed in the patent it's about $10 of the BOM cost in ICs in each derailleur.

Of course Sram will charge whatever the traffic will bear, not based on their BOM cost.

[pdlpsher1]

One thing that I was thinking about that seems problematic is that with a wireless system all the (complex)
I'm pretty sure that high end mechanical systems will never go away and will continue to be refined and developed alongside electronic grouppos.

One thing that limits a mechanical group is that as more gears are added it demands a level of precision not currently cost effective in a mass produced product. With electronic shifting I could see 12 or 13 speeds on the horizon

[showdown]

Thanks for the info Eric- interesting for sure!

When Di2 was first introduced I was highly skeptical and didn't see the benefit over a mechanical system. Now having owned Di2 for a few months I can say I'm a total convert. I love the system and can see many benefits (for me) including laser fast and precise shifting, perfect front ring shifting under load, excellent performance when cross-chaining, and of course satellite shifters and programmable buttons.

I won't doubt SRAM's offering yet but I have to ask- what benefits would a wireless system provide that a wired one couldn't?

I get that it might look cleaner but that's not a functional benefit. Ease of setup doesn't strike me as a benefit really... Is this a case of doing it because it can be done or are there any actual functional reasons to go wireless? Weight savings is in theory a benefit but not until the UCI changes the rule on bike weights...

So, why wireless?

[deek]

Looks, honestly. What do you think sells better though, a wired or wireless bike computer/powermeter/etc, especially in the high end market?

Like Eric said, it would also be a little lighter by the fact that you're eliminating the wires, but that is quite a lot of effort to save 15g.

[BeeSeeBee]

I'd say as a differentiator mostly. With most frames these days having good electronic integration, you're looking at maybe 10-15cm of exposed wiring in total. It's also somewhat of a set it and forget it thing, once it's wired up, you really don't have to muck around with it like you do with changing cables. If wireless can be done without compromise (function, price, stability), I'm all for it, but it alone wouldn't be a big deciding factor for me. I hope SRAM's offerings brings the price of all the systems down a bit, I'd adopt in a heartbeat if it was just a wee bit cheaper.

[eric]

Weight savings is always a benefit. The UCI weight regs affect a tiny part of the consumer base. In the US only a few amateur races (like national TT championships) follow them. The rest of us amateur racers can have bikes as light as we can afford. And of course most bike consumers don't have racing licenses.

I'm not sure it's that much more effort do develop a wireless system vs a wired one. The chips and protocols are standard off the shelf. They probably buy the 802.15.4 software stack from someone as well. So that'd handle the communications. What's left is the "business logic" of actual shifting, derailleur positioning etc, plus the wakeup stuff described in the patent.

On a wired system, I think you'd go with an existing standard like CANBUS (used in cars, so you don't have individual wires running to all components, they're on a bus like computers on a local network). So you could buy off the shelf chips and microcode again leaving the actual shifting logic to be implemented.

The RF engineering like preventing interference, and certification would be extra.

Whatever the practical benefits I'm sure that marketing will be the biggest benefit. Sram's last to the electric shifting party. They have to either make theirs perform much better (and Di2 is pretty good from what I'm told) or add a feature that no one else has.

[53x12]

I love SRAM mechanical and personally prefer SRAM's mechanical over the other two. Just personal preference.

However, while this SRAM wireless group sounds interesting, I'm not sure I would pass Shimano's Di2 offering. Shimano has it nailed imho. I don't want to pass judgment on SRAM as it obviously hasn't been released yet and we have minimal info. But I'm not so sure about this. Just a little skeptical I guess.

[weenie]

if you hop freqs the guy will just blast a signal on all freqs

It appears that they're using DSS frequency hopping.

DSS is not FH
also both are very easy to jam (with less than 100w but id just imagine a dude in his car)

For example I jam my entiere wifi spectrum (the whole 2.4ghz band in this case, obviously could do the same on 5. with a single usb wifi stick even thus theres 14 channels and its DSS. I just hop freqs fast and send white noise.

Its actually quite hard not to be jammed by someone who wants to jam your signal.
its also possible to locate the jammer if he emits for long enough but psst... radio police every 100 meters wont happen

[ichobi]

Theres no reason for SRAM to release a wired e groupset. Di2 is six years old and has it nailed. Unless SRAM can top this, there's not much point getting SRAM when UI2 is already almost as good as DA Di2, and probably cheaper than whatever SRAm is going to sell.

Pretty sure it will be wireless. Though Rotor groupset is interesting. From what J heard from the second largest Rotor distributor in Asia, it will take us by surprise. Electronic probably, wireless may be the technology is here, will e interesting for sure.

[pdlpsher1]

with less than 100w but id just imagine a dude in his car)

That 'dude' could be your DS in the team car A sudden and unexpected upshift means it's time to attack.