個人積分：38分
文章編號：50168748
個人積分：0分
文章編號：50169932
個人積分：401分
文章編號：50169980
yuettoi wrote:
機械士只得雙手, 怎...(恕刪)
應該不會這麼笨才對
既然都無線了，應該會開發一個app可以用手機連結測試，升級軟體，看電量等之類的
或者會附一個連結的硬體讓用家使用
Pairing all of the bits together also sounds like a simple process that should be well familiar to anyone with a Bluetooth headset. Holding down a button on the derailleur will put that component into pairing mode, which is indicated by a flashing onboard LED. The derailleur will then scan for a corresponding shift paddle push, at which point the LED will go solid and the two bits are paired.
個人積分：401分
文章編號：50170103
個人積分：54分
文章編號：50171030
個人積分：38分
文章編號：50194299
https://www.youtube.com/watch?v=lWzdWMapJ-c&feature=player_detailpage
個人積分：38分
文章編號：50235246
SRAM's wireless shifting—a saboteur's dream?
Could hackers attack SRAM's electronic gears? And what does film star Hedy Lamarr have to do with it?
SRAM’s new wireless groupset has created a lot of discussion and debate. A common concern is whether it would be susceptible to electronic attack, either to stop it working completely or for instance, to operate a rival's gears at just the wrong moment, leaving a sprinter twiddling a tiny gear with 200m to go.
So we asked a man who knows. Mark Severs B.Eng is a Senior Systems Engineer for communications giant Arqiva whose day job involves making sure TV programmes get to your screen. He used to write under the name Andy Bentley for cycling and other publications in the early 90s, until he got a real job. He knows a bit about how widgets talk to each other, so we asked what he thought of the SRAM system based on what we know so far.
He told us:
First, the comms protocol has to be a legal one, i.e. approved by every country's radio regulator wherever they will use it. That means that it must be one already recognised by the ITU, he international talking shop for national comms regulatory bodies such at the USA's FCC and Britain's OFCOM. This means that even if it is a bit proprietary it can't be all-new.
Second, Bluetooth and wifi and stuff like that are probably out because they are suited to more to communications and less to control. Wireless control systems are different to wireless comms systems. Also, Bluetooth is very slow and pretty easy to selectively disrupt.
There are a lot of options, but the likely answer is one of the comms protocols used for industrial and domestic control systems that already exist.
As far as disruption goes, there are two ways to disrupt comms; selectively and blanket. If you spew out enough shash in the relevant section of the radio spectrum, everything will fail, affecting all teams equally. That's blanket. Are any other teams using a similar system? A system in the same band? A band near to the band used for their voice radio? If only one team is using a specific band for their "derailleur brains" it is a simple matter of radiating a blanket jamming signal across that band, like one side used to do to the other in the cold war. Jamming a specific frequency is more fiddly but also possible, if you need to get that specific. This form of jamming is illegal but hard to detect without proper tracking systems designed specifically to detect jammers, so you just switch the jammer in the team car on when the heroes get involved in the break, the climb or the sprint.
At this point we dug out the SRAM patent and in particular a paragraph relating to the wireless protocol, which says it's a “2.4 GHz transceiver utilising AES encryption and DSS spread spectrum technology supporting 16 channels and the IEEE 802.15.4 communication protocol." That might as well be Navajo to us, but it spoke volumes to Mark.
It's an ISM or Zigbee/Z-Wave style product then, co-opted for bikes. There are a whole slew of these, too many to list. They are all semi-proprietary, but all available as "off the shelf" chipsets. In this article, there is a table with ISM in the middle, and all the options are just listed as "various".
Specifics: The AES encryption means hard-to-hack, so forget spotty hackers homing in on one specific bike's comms. DSS means "Digital Spread Spectrum", which is expected, and is simply a mechanism for making the radio signal robust and hard to interfere with - you know, by things like microwave ovens, wifi (which lives in the same band), poorly suppressed ignition, etc. DSS is used in everything these days (digital TV, DAB radio, DECT and mobile phones), so it is nothing exotic.
The IEEE 802.15.4 bit is just an international standards listing for physical and MAC activity [Machine Access Control]. You know, like a computer has a MAC address? The patent isn't very "patenty" in that none of this is a new invention, it's all a couple of years old at least. Spread-spectrum was invented by the famous film star Hedy Lamarr in the 1940s, which is one of the most obscure and arcane pieces of trivia I ever learned. She was a maths PhD!
It looks like it is all a versatile comms standard, bidirectional or even meshed maybe, robust, reliable in areas of interference. This no doubt drives some sort of miniaturised by fairly ordinary mechanical actuator system, and there is nothing new in all of that since electronic engine brains in motorbikes shrank all the sensors and actuators for use on throttle butterflies etc etc.
All told it sounds very realistic and workable, based on existing proven technology and impossible to interfere with except for the "blanket" approach I mentioned earlier. Using wide-band spread-spectrum may even make this impractical, which is entirely possible.
There you go then. Thanks in part to a bright idea by a mid-twentieth century film star, SRAM's wireless shifting should resist the kind of electronic attacks people are worrying about.
個人積分：22分
文章編號：50236176
個人積分：38分
文章編號：50238363
SRAM "Wireless" Group Won't Be Available Anytime Soon
Excitement and enthusiasm continues to abound the cycling world, after SRAM's "skunkworks", fully wireless groupset was spotted during this year's Tour of California onboard Bissell Development Team's bikes.
However, according to information that SRAM shared with an online cycling publication, they said "don't hold your breath", with regard to availability being anytime soon. In fact, the brand suggested that the wireless groupset was still at least two years away from production. To wit:
“Yes, the technology is wireless.
“But it is NOT a Model Year 2016 OEM product however.
“This product technology is still in a long development phase with much testing and refinement yet to occur.
“As soon as we develop commercialization plans, we will provide an update.”
Curiously however, the UCI's technical rules stipulate that prototype equipment can't be used in a race, unless said product is going to become available for sale within a nine month period from the date of use.
This raises the following possibilities:
1. Team Bissell didn't actually use the wireless groupset during the race, and SRAM merely seized the opportunity to "tease" observant onlookers during such a high profile event.
2. A lack of enforcement on the part of the UCI during their own sanctioned event ?
3. Or, perhaps SRAM is trying to throw everyone off it's tracks, with plans of putting the groupset into production sooner than the brand is willing to admit to at this point ?
If you ask me, two years is a long time for SRAM to sit back and watch Shimano and Campagnolo beat them to the punch. And, they surely will - if that's the case.
個人積分：407分
文章編號：50239177
不管怎麼說有線的版本起碼已經是實品，這幾周披露的訊息很多都是針對煞變把操作性專利的問題(被C家卡住)，
最近電子媒體的文章也並沒有針對測試中的"有線"電子變速有很多的詳細報導，最起碼可知道的事已經有具體架構的實品測試中；在登山車的部分更是不得不先丟訊息出來，因為對手已經把東西準備好。
無線傳輸的部分可以作為一個突破點很正常，因為對手(們)都沒有針對這方面有消息透漏，更別提產品(Shimano只做了一個對應碼表的檔位無線傳輸)；無線傳輸可作為一種技術上的突破。
不管怎樣起碼2015年有機會看到SRAM的"有線"電子變速市售的可能。
有關自行車與重量訓練或慢跑可PM交流互換意見，其他一律忽略之。
