A patent filed by SRAM in September and
first spotted by Bicycle Retailer and Industry News could reveal a version of electronic shifting that has the potential to be cheaper than its current AXS offerings.
SRAM's current electronic drivetrain is totally cable-free and uses a small electric motor, two clutches and a gearbox to actuate the derailleur, plus an encrytped wireless network to relay inbetween the shifter and the derailleur. In short, it's a very complex, high-tech piece of equipment that sits right at the top of SRAM's range and it carries a justifiably sizable price tag along with it.
This new design is totally different from that, and looks similar to a device we tested in the past from
Archer Components. This system uses a standard mechanical derailleur, but instead of the cable being routed inside or along the frame to a shifter on the handlebars, it is cut short and fed into the cable puller that sits on the chainstay on the drive side of the bike. This cable puller is then operated wirelessly from a handlebar switch. It's easiest to think of it as a chainstay-mounted shifter that you operate from your handlebars.
There are definitely similarities between the Archer D1x we tested in 2018 and SRAM's new patented design.
The Archer D1x gives a pretty good idea of how the SRAM patented design might work
The main difference between the SRAM and Archer pullers comes in how they are powered. Whereas the Archer 1Dx uses a small removable battery, much like SRAM's own AXS, this new design will rely on the power of an e-bike's battery. The patent says: "Previous designs of electronic cable pullers were self-powered, often relying on batteries... The present disclosure provides examples of electronic cable pullers that may be powered by a centralized battery of an electric power assisted bicycle ("e-bike") and may not be internally powered."
Translating that patent-ese, we believe this design will be something that is integrated into the electronics of an e-bike. This is something we've seen previously with headlights, ABS and even
4G computers but this would be the first time derailleur shifting would be involved with that as well.
On top of this, SRAM even hints that the product wouldn't necessarily need rider input and could shift automatically to provide the best cadence for a rider depending on the terrain they are riding, or if they change the power mode of the motor. While the patent does include a diagram of a potential shifter design, the patent also says, "Additionally or alternatively, the shift control may send the gear change signal to the electronic cable puller without user input. For example, in response to a sensed change in terrain or heading, the shift control may automatically send a signal to the electronic cable puller to change gears. In some cases, the shift control may be part of or in communication with a controller of an e-bike. The shift control may send a gear change signal to the e-bike controller which may send a signal to the electronic cable puller via the wire to change gears.
So, why would SRAM make this product when it already produces a wireless drivetrain? Simply, this strips away a lot of the intricacies of the AXS system so will likely be a cheaper and simpler way to get rid of handlebar clutter. There's still a lot we don't know about this system though. Is it designed with mountain bikers in mind? How much is it expected to cost? Will it ever even see the light of day? And does SRAM have more plans for e-bike integrated technology? SRAM is tight-lipped about its patents so we'll have to keep guessing until it's ready for the market.
View the patent,
here.
Manufacturer cost for AXS its about 30 percent of the retail price.
You can use much smaller and lighter cassette than 10-51 and have the same gear range.
Imagine having narrow 7 or 8 speed cassette - less cross chaining means less drag,
Hub can have wider spoke flanges - no need for boost/super boost? Can be used on any bike, if you switch the frame, you keep the wheel and run it on new bike.
You can use any crank you want, no need for proprietary nonsense.
For those interested, check the articles linked below.
www.pinkbike.com/news/revonte-launches-a-stepless-e-bike-motor.html
www.pinkbike.com/news/a-look-inside-the-automatic-and-stepless-revonte-one-drive-emtb-system.html
Also, handlebar clutter?! Really, we're talking one cable here as the shifter is still present... and also bear in mind that with a mechanism like this they'll probably lose the weight benefit of their current system over the standard cable actuated set up. I guess as it's solely for the e-bike crowd though weight won't matter so much.
Fact is chain-on-sprocket is far better for power transfer than any spur gear assembly. Gear shifting mechanisms are extremely complex, requiring either engagement dogs shifting forks and barrels or planetary gears, sprag bearings, clutch plates and shoes.
Both the manufacturers and the consumers of this sport are short-sighted, stubborn, and close minded to a certain degree, but especially the manufacturers. That's why there is only 1 manufacturer that makes a real DH e bike(Husquavarna), and it isn't anything special.
If people still want derailleurs on their regular snail bikes that's understandable, they are so slow they need the efficiency. But it is time for derailleurs to be thrown into the trash bin of technology for the majority of e bikes.
Could a person with ill intent just blast a bike with a little EMP and completely ruin someone's day?
Note I would do such a thing because I'm not an a*shole, but plenty of those people do exist.
Check out: IEC 61000-4-6 and IEC 60950-1
Anyway, I would believe it and of course the switching frequency of your coil will dictate what gets jammed. FM is a continuous wave low-frequency transmission, so if you were switching in the 100 MHz range then that makes sense.
To jam AXS devices you need to have 2.4GHz transmitters which emit a continuous wave very close to the receiver, which in and of itself can be violating the specifications under which they were certified.
No, you don't need 2.4GHz to jam axs, you just need a frequency that interferes with any critical part of the circuit, as any length of conductive area in the PCB is potentially an antenna you just need to induce an high enough voltage, through the resonant frequency to disrupt correct functionality, the only hope is them having put enough RF decoupling capacitors and eventually coils, at least for GSM, LTE, etc, I believe they have.
Serious question because I've only tried ebikes a few times. I found that pedalling efficiency on the ebike was not an issue, so I'd prefer the suspension to be tuned to absorb the terrain and didn't care about support when cranking at all.
Is it novel? Doesnt look novel. So what is the value in the parent?
It amused me some of the things we could patent and some of the things we couldnt.
Could this be a blocking patent rather than an application one?
When we see the likes of say Weagle apply for a patent because he moved a pivot point 3mm you realise for the most part they are nothing more than a dick measuring instrument.
Some companies encourage their R&D employees to come up with blocking patents, these are designed to block a competitor from further development of a product, both in direct technology and adjacancies.
Trying to come up with methods for patent avoidance can be part of the art of engineering.
There are countries who like making counterfeit goods or buying legitimate registeted goods from a country where they are cheaper and repackaging them. Both can be illegal if a product has to be registered for example. Companies may have teams who go after these counterfeit operations or patent infringement companies.
Different countries have different rules around patents and products and different registrations for patents/products etc. Knowing this landscape is a minefield and left to regulatory experts, both locally and globally.
I see Porsche came out with a variable pin height connecting rod for engines recently. The design is fraught with problems (such as hydraulic poggo, weight and piston slap due to the eccentric pin) and perhaps that is their intention - to block.
The power usage of tiny derailleur motors and its control system is tiny compared to the ebike motor and its drive circuitry. If they plan out a system shutdown sequence when the battery gets low, they could turn off the motor and still have enough charge for everything else on the bike (displays, handlebar controls, head and tail lights, derailleur, suspension controls etc) to work in low power modes for days. Of course, if they don't you have an expensive adult kick bike.
For example- you can still use your car stereo when your car battery is too flat to kick over the starter motor.
Seemed perfect , just 8 speeds with narrow width cassette made of steel and 11-46 gears, what more do you need / want ?
Prices looking good,
Shifter £48
Rear mech £140
Chain £25
The all steel cassette, must be cheap, just checking, oh must be an error, £425.
Double check, yep it really is £425, they decided to machine it out of single piece of steel.......
On top of that the chain is effectively a 10 speed which means it probably will not work with the 11/12 speed compatible X-Sync chainrings for the new motors. ( They did make compatible front rings for the earlier ebike motors though using the tiny cogs)
They should revisit this and make a cheaper pinned steel cassette like GX or even the cheaper NX and a 10 speed compatible front ring.
I sure they would get plenty of sales , would happily use it on a non-bike.
XSHIFTER
back in 2017 I launched the news on
www.kickstarter.com/projects/1598276649/xshifter-worlds-first-universal-wireless-smart-shi
#sramstolen
I do think most people that think about this BS, should ride more, and feel the real need of any MTB that spends some hours on the saddle.... in the moutains!