SRAM goes electric....(almost official) Has Landed

Discuss light weight issues concerning road bikes & parts.
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Butcher
Shop Owner
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by Butcher

Yeah, between Campagnolo and Shimano, I'm certain it would be difficult to come up with idea that has not been patented.

BmanX
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by BmanX

Sometimes late to the party is a good idea. Let SHITmano and CampaNOGO sort it all out and then look at what can be done much better and bring it to the market.
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Zigmeister
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by Zigmeister

I do like the idea of wireless, and the FD/RD each has it's own battery. Don't know about the lever though to shift? Must have some battery for the transmitter as well. Since I've only charged my Di2 9070 3x times in 9 months, I would assume having to swap the charge cable to the other points a few times a year is a minimal hassle. And not having to deal with running wires inside the frame/fishing them around, etc..eliminates a lot of hassles on setup/maintenance/swapping.

rijndael
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by rijndael

The charging cable may be octopus-like and you can charge them all at once.

Pharmstrong
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by Pharmstrong

The components each have their own removable battery, so it will be a charging dock.

Johnny Rad
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by Johnny Rad

For those who are afraid the battery(s) will be dead when they want to ride, how often do,you find your computer battery dead? Sure, it's possible - but, a long shot not to lose sleep over.

ProEvoSLTeamHighMod
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by ProEvoSLTeamHighMod

I want to know if it will support 1x!

mika
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by mika

do you know if Sram will release direct mount brakes for canyon aerod, trek emonda...?

FIJIGabe
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by FIJIGabe

I don't think they are. They've been testing the new groupset on the Team Bissell Madones using the standard Bontrager brakes (not the new ones), so that leads me to believe that they are not developing direct-mount brakes at this time.
Madone 9 https://goo.gl/7UwZpV
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StevieB
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Joined: Wed Apr 09, 2014 2:54 pm

by StevieB

SinPhi wrote:This has me wondering if the possible function of a front gear change also changes a few cogs in the rear to do just what you would with a mech group, seems to make sense that it would. I now I change both at the same time for nearly every front shift. Would end up being a sort of hybrid between sequential and manual.


I for one will be very surprised if it doesn't come out with this functionality, at least as a programmable option. Would be easy to do, and with the improved timing and synchronization afforded by electronics it should make for very reliable changes. I run DA9000 mechanical (9001 levers) with a SRAM chain catcher, and tend to hit both levers simultaneously now more often than not when changing rings up front. Never did it in the past, but with this group it's dead-easy, super-smooth and never misses a beat.

Depending on front rings and rear cluster, you'd just program the rear to move 1-3 cogs simultaneously whenever you switch chainrings. And of course if you didn't want it, it would be easy to program it to just swap front rings. Only reason whatsoever for it not to have that capability might be potential patent issues.

JN2Wheels
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Location: Maryland

by JN2Wheels

I also usually shift both at the same time, so I've been thinking about this. While I don't think tapping both shifters with a quick following tap/s to whichever paddle is needed would be difficult, I think it loses an opportunity.

A system like this should be aware (programmed) of the specific gearing used and know where in that gear combo you are. Therefore, I hope SRAM allow the following:

When shifting up to the big ring, use the gearing info and position to automatically select the appropriate rear cog to give the next hardest gear combination available, whether that be one shift or two, making the step perfectly in sync. Likewise, when dropping to the small ring, choose the appropriate rear cog to give the next easiest combo available. Smooth transitions, done by knowledge of specific gearing inches and position. Should be easy.

Almost all scenarios would be covered by this. The only scenario not covered - dumping or bumping up. If dumping or bumping, just continue tapping the appropriate shifter. Easy peasy.

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kkibbler
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by kkibbler

JN2Wheels wrote:A system like this should be aware (programmed) of the specific gearing used and know where in that gear combo you are. Therefore, I hope SRAM allow the following:

When shifting up to the big ring, use the gearing info and position to automatically select the appropriate rear cog to give the next hardest gear combination available, whether that be one shift or two, making the step perfectly in sync. Likewise, when dropping to the small ring, choose the appropriate rear cog to give the next easiest combo available. Smooth transitions, done by knowledge of specific gearing inches and position. Should be easy.

You're basically describing sequential shifting. But, I doubt that this SRAM setup will allow it.

Speculation: I believe the signaling logic is setup such that...

Left lever sends signal L
Right lever sends signal R

RD receives L alone, shift down
RD receives R alone, shift up
RD receives L+R, do nothing

FD receives L alone, do nothing
FD receives R alone, do nothing
FD receives L+R, checks where it is now, and moves to the other position

That is extremely simple circuitry, no junction box needed. But for sequential shifting you need a unit to interpret lever input, store current RD/FD state, and output instructions to the FD/RD. This SRAM setup doesn't appear to have any memory or processing, unless it is all tucked into the hoods (doubtful).

djwalker
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Joined: Sat Oct 31, 2009 7:35 pm

by djwalker

The question about the SRAM system is without a central processor how does one derailleur know what the other one is doing? For auto trim of the FD or sequential shifting the two derailleurs need to know each other's state. That would imply that the derailleurs need to be able to talk to each other over the wireless link. Either that or there would need to be some smarts in the shifters themselves. Having smart shifters would make remote shifters more difficult so I would guess that any smarts would be in the derailleurs. I don't think it would be very hard for the derailleurs to talk to each other which would make all these features possible. The calculations are not very complicated and wouldn't need much processing power to execute.

JN2Wheels
Posts: 219
Joined: Sat May 09, 2009 3:03 am
Location: Maryland

by JN2Wheels

You're basically describing sequential shifting. But, I doubt that this SRAM setup will allow it.


Yes... But... Only sequential when the rider wants to shift the big ring. The huge problem with full sequential is the loss of control over the big ring shifting as the "computer" decides what is next. My logic eliminates the loss of control, and instead only uses sequential programming when the user decides to shift front chainrings. Seems like a great implementation in my mind.

SkippyMcJimmelstein
Posts: 33
Joined: Mon Oct 28, 2013 11:08 pm

by SkippyMcJimmelstein

kkibbler wrote:
JN2Wheels wrote:A system like this should be aware (programmed) of the specific gearing used and know where in that gear combo you are. Therefore, I hope SRAM allow the following:

When shifting up to the big ring, use the gearing info and position to automatically select the appropriate rear cog to give the next hardest gear combination available, whether that be one shift or two, making the step perfectly in sync. Likewise, when dropping to the small ring, choose the appropriate rear cog to give the next easiest combo available. Smooth transitions, done by knowledge of specific gearing inches and position. Should be easy.

You're basically describing sequential shifting. But, I doubt that this SRAM setup will allow it.

Speculation: I believe the signaling logic is setup such that...

Left lever sends signal L
Right lever sends signal R

RD receives L alone, shift down
RD receives R alone, shift up
RD receives L+R, do nothing

FD receives L alone, do nothing
FD receives R alone, do nothing
FD receives L+R, checks where it is now, and moves to the other position

That is extremely simple circuitry, no junction box needed. But for sequential shifting you need a unit to interpret lever input, store current RD/FD state, and output instructions to the FD/RD. This SRAM setup doesn't appear to have any memory or processing, unless it is all tucked into the hoods (doubtful).


Yes, this is probably it but I think I'd much prefer the system use the rising edge of the shift buttons for a more responsive and engaging drivetrain. For it to work in your example it would have to use the falling edge for the L+R logic to work.

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