SRAM Powertrain Deniz Merdano 32
First Ride Review

SRAM Introduces Powertrain eMTB System

Photos Deniz Merdano
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I guess we should have seen it coming. Just like we should have seen T-type coming. The idea that SRAM was producing a universal derailleur hanger as some sort of philanthropic endeavour seems a little farfetched in retrospect. It does mount more securely and improve the performance of every derailleur that gets bolted to it, SRAM or otherwise, but it's clear this was more than just benevolence. UDH has benefits for everyone, and that's great, but that now seems more like a bonus feature; SRAM wanted bikes to be UDH-ready so they were also Transmission-ready. That's not a slight. That's acknowledgement of a savvy business move.

And now we see what Transmission was really about as well. Again, it's a system with benefits for any rider who wants to drop the cash and experience shifting that actually improves under load, but it's also clear that integration with an electric motor was always part of the plan.

SRAM Powertrain Deniz Merdano 16

There is a small display that shows very basic info, but nothing new on the bars if you are using SRAM's Transmission Pods.

And SRAM Powertrain certainly is integrated. If you have the pods that control SRAM's AXS derailleur and seatpost, you have what you need to control the Powertrain system. The pods are used to dictate what mode you are in, turn Auto Shift on and off and adjust that system on the fly to mesh with your preferred cadence. The parallel nomenclature is not coincidental; Transmission was designed with Powertrain in mind.

None of this is sinister or unethical, and the order of releases, first UDH, then T-Type, and now Powertrain, had to happen in that sequence. For consumers looking for an intuitive, easy to use and understand eMTB motor, battery and controller system, SRAM Powertrain looks like a solid solution. Still, having the wool pulled over is never a good feeling, even when getting duped may be in the best interests of some of us.

powertrain system overview

The SRAM Powertrain System.

SRAM Powertrain Highlights

  • Brose drive unit - 90 nm peak torque, 680-watt peak power
  • Two power modes: Rally and Range.
  • Two batteries available: 720 Wh (4.1kg/9lbs) or 630 Wh (3kg/6.6lbs).
  • 720 Wh battery charges in 5 hrs, 630 Wh version charges in 4.5 hrs.
  • All controlled by SRAM Transmission shift pods (no extra controller needed).
  • Bike manufacturers can mount the battery to be removable or semi-fixed.
  • Auto Shift will select gears based on data collected by the system and can be adjusted to suit your preferred cadence.
  • Coast Shift allows you to manually force a shift while freewheeling by turning the chainring for you in times when pedaling isn't wise.
  • AXS Bridge Display provides power mode, battery life and Auto Shift mode info.
  • Available 250 Wh range extender.
  • Current brands featuring SRAM Powertrain: Transition, Nukeproof, Propain and Gas Gas (models not yet released).
SRAM Powertrain Deniz Merdano 29

Motor hardware by Brose, which is also Specialized's motor partner.

A SRAM Motor?

Chris Mandell, SRAM's North American PR Manager (and much more) was pretty clear that this motor is made byBrose.* The name is right on the side of the power unit, beneath SRAM's word mark. In terms of hardware, apparently it isn't radically different to other Brose motors. Which may mean it's identical. SRAM's contribution was in software, controls and integration, making the motor interpret inputs in a way that best suited the company's goals, and making it all work with Transmission.

*Pronounced Bro-suh

SRAM Powertrain Deniz Merdano 1

I was riding a yet-to-be-released Nukeproof Megawatt. I liked it a lot.

Inaugural Brands running Powertrain

There are four bike companies spec'ing the entire Powertrain system: Transition, Nukeproof, Propain and Gas Gas. None of these models have been released yet but I can tell you I was very impressed with the Nukeproof Megawatt I tested the system on. It handled the first wet conditions of the fall really well and had a very natural and balanced feel. More importantly, it never held me back.

SRAM Powertrain Deniz Merdano 31

The manufacturer can decide if the battery is mounted semi-permanently for a lighter and more compact package, or allow it to be removable for riders who may want multiple batteries.

Integration

Unlike Shimano, Bosch, or even other Brose motors, Powertrain can only be used and controlled with SRAM Pod controllers. Every other system I know of has a controller that is independent of the drivetrain and seatpost. You could still use a cable-actuated SRAM or possibly even Shimano drivetrain (this may need some tinkering), but you'll still need at least the right side SRAM pod controller and you won't get Auto Shift or Coast Shift unless you have Transmission. You can get away without the left hand shifter, if you opt for a cable-actuated seatpost, because the button on the display will change the power mode, which is all the top left hand pod button is responsible for.* It's clear, however, that SRAM wants you to be using Transmission if you are riding a Powertrain bike.

*without the left hand pod, it seems you would also lose access to Push mode, which helps you move the bike uphill in situations where pedaling isn't an option.

SRAM Powertrain Deniz Merdano 6

The Powertrain display provides only basic information.

SRAM Powertrain Deniz Merdano 3

If you'd like speed, distance and other information you'll need to add your own device. Push mode is SRAM's version of a 'walk' mode, which helps you get the bike up steep hills if you can't pedal.

How Many Modes do you Need?

You might be wondering how you can control modes when there is only one pod button left over once you have accounted for your seatpost and the up and down shift buttons for your rear derailleur. The remaining button, on the top left hand side pod, does the mode controlling while you are on the trail. This works because SRAM has only programmed two pedaling modes into the system: Range and Rally. You can guess what each does immediately, unlike the modes in the Fazua motor used by Transition and Santa Cruz (Breeze, River, Rocket and Boost). There is also a walk mode, which SRAM calls Push, that is engaged by holding down the same upper left side Pod button.

This is probably the biggest departure most riders will notice, considering some other bikes have as many as five modes and none that I've ridden have fewer than three. I know many riders who use all of them on most rides, and some who rarely use the most powerful mode.

AXSapp RideModes Range rally

Both modes are adjustable but the Range mode can be adjusted between 70 and 540 watts.

If you are in Rally and you hit the top left pod button, you'll switch to Range, and vice versa. This is easy and intuitive, but it seems to me many riders will want more. While Range is the lowest power mode, and is clearly positioned to give you longer battery life, on he bike I rode it wasn't set to an equal level to the lowest power mode on other systems I've used, like Shimano's Eco. Instead it was somewhere between Shimano's Eco and Trail modes and not dramatically less powerful than Rally. Once the app is available, riders will be able to tune both modes up and down with Rally mode being tunable between 550 and 680 watts and Range mode between 70 and 540 watts. Most riders will be able to figure out where they want their two modes to be, and in a pinch, if range anxiety kicks in, you will be able to use the app to tune that lower mode to help get you home. It won't, however, be as easy as clicking a button once or twice, or even three times.

SRAM Powertrain Deniz Merdano 42

Chris Mandell was riding another yet-to-be-released Powertrain-equipped bike but his was from Transition.

Riding Powertrain

I only had one day to ride Powertrain but we managed to suck the marrow out. Deniz had injured his shoulder the day before so instead of joining us for the ride and snapping photos as we went, he was on foot. We met him on lower Seymour to get some product and riding shots and afterward began climbing to the top of the mountain.

SRAM Powertrain Deniz Merdano 25

The bikes climbed very well indeed with lots of power available.

Riding Auto Shift

On the way up I tried the Auto Shift function. The system uses real time data to determine the best gear for the situation, based on your personal cadence preferences, which can be adjusted on the fly. Engaging the system is easy; a long hold on the upper right AXS pod button turns it on in the medium setting. If you'd like to adjust the target cadence up or down, you long-hold the lower right controller and then use either button to increase or decrease the value between 1 and 3 levels. This means you can be + 1 to +3 or - 1 to -3 from the M cadence value, meaning there are a total of 7 cadence levels.

The first section we rode was the Baden Powell from Indian River road to the outhouse on Mt. Seymour road, part way up the mountain. The climb is a series of punches with lower angle sections in between, and this pattern is relentless. As Chris pointed out, the system can't anticipate what is coming; it is only aware of what is happening in the present so you can easily find yourself in the wrong gear, at least momentarily, as the terrain changes. There is a solution, however.

At first I needed to train myself keep my hands off the shifter so I just put up with those wrong gear moments. Once Chris reminded me of the override function, I began to use it, shifting in advance of steep sections and any time when I felt the gear selection didn't match the terrain we were coming to or had already arrived at.

SRAM Powertrain Deniz Merdano 33

Auto Shift knows what is happening, when it's happening, but it can't see the future, making the override function very useful.

Part of my struggle was a symptom of SRAM's AXS post line up, that still fails to include a 200mm or longer post, so I had the 170 set too low to deal with the effort required when pushing a gear that was a little too big. Once I pulled out my tool and raised my saddle, things improved, until the descent when I lowered it again.

As Chris was explaining Auto Shift, and how you could override the system when it doesn't match the situation, it made me think of cruise control in a car. Or at least older cruise control, since so many new cars have adaptive cruise that will brake when you follow too closely behind the vehicle ahead. They won't however, automatically speed up when you need to pass or accelerate for some other reason. Fortunately, any touch of the gas or brake temporarily overrides the cruise, just as hitting the shifter does when Auto Shift is on. This combo of manual and auto works well, but I'm not sure it was better than controlling the shifting myself in a situation where the pitch changes rapidly and frequently over a significant distance.

powertrain rear sensor

Most systems have a single magnetic sensor at the rear wheel. SRAM opted for six to get more data per revolution.

In other situations Auto Shift worked well, even downhill. A bonus when descending is that you can also use Coast Shift. If you are hurtling downhill and rapidly approaching a punchy climb, you can use the pod shifter and change gears without pedalling, since the motor will turn the chainring for you. This will be particularly useful if the descent is challenging and you are unable to turn the cranks effectively or are afraid of banging a pedal. The Coast Shift function can be used when Auto Shift is turned off as well but it must be enabled on the app, which I wasn't able to use at that point.

SRAM Powertrain Deniz Merdano 13

The T-type rear derailleur on Powertrain-equipped bikes is no longer wireless. Power comes from the main battery.

SRAM Powertrain Deniz Merdano 10

Like the Trek Fuel EXe I reviewed earlier, which also had a hard-wired AXS rear derailleur, the battery is likely programmed to keep a reserve power level so you'll have a few hundred shifts after you've exhausted the battery's pedal assisting duties.

A SRAM Advantage

The biggest plus I see about choosing a SRAM system versus some others on the market is after sales support. SRAM has been ramping up their ability to provide service locally in many parts of the world including here in B.C., meaning your bike or motor shouldn't generally need to be sent somewhere far from where you live, should you require some technical or warranty service.

SRAM Powertrain Deniz Merdano 37

The plug interface.

SRAM Powertrain Deniz Merdano 35

There are no aftermarket battery options, at least not from the initial spec partners.

More on the Ride

In terms of power delivery, Powertrain has a less abrupt engagement on the first pedal stroke than most others I have tried. This is likely a positive for newer riders of eMTBs, or when grip is compromised, but I have become used to a quick ramp up and I feel like I can use it effectively in spots where it's tough to get going. Traction was a stand out for Powertrain though on a couple of tough climbing sections.

Overall I was impressed with the manners of the system and, independent of Auto Shift, found it very easy to get along with. There was lots of power when I needed it and the delivery felt natural and smooth.

I didn't charge the bike so I can't comment on the plug and as far as the display goes, unlike other systems, I never looked at it while riding.

SRAM Powertrain Deniz Merdano 21

The Nukeproof was a blast to ride. The company is making a push into North America, which seems like good news for riders.

Powertrain Pricing

There was no information on what this system costs at this point, for several reasons. The first hurdle is that the bikes that will be spec'ed with Powertrain this year haven't been released yet and, even if we had those numbers, there would be embargoes on that information for now. Beyond that, a SRAM/Brose motor won't fit into a frame designed for Shimano or Bosch motors. Each has its own size and shape and they aren't interchangeable, meaning these are not generally aftermarket products. It's even difficult to price out the difference between this motor and an equivalent bike with another motor, because SRAM Powertrain bikes will be spec'ed with T-type, which means they will already command a hefty premium over a comparable bike with a cable-actuated drivetrain. We do know that this will be a premium spec, even within the pricy world of performance eMTBs.

SRAM Powertrain Deniz Merdano 41

No word yet on a more affordable version of Powertrain, but SRAM has a history of trickling innovations down to lower price levels.

Just Riding Along

This sounds like a lot, but the system works pretty seamlessly. You can leave Auto Shift off, and stay in either Range or Rally if you like, and just ride your electric bike normally, but with the advantages of SRAM's Transmission, which are ideal for the added power of an eMTB. The Brose motor, notably also adopted by Specialized, is acknowledged as one of the best available and I was impressed by its performance. I was also surprised by how quiet it was, at least on the Nukeproof Megawatt I was riding, which may have isolated the sound better than some others. It's certainly not virtually silent, like the lower-power TQ motor on the Trek Fuel EXe, but it's very subtle when you aren't putting in a big effort, and when you are, it's more of a whirr than a whine. I found it less unpleasant than most.

While there is nothing earth shattering here, it all works very well and I'm looking forward to getting more time on SRAM's Powertrain system in the future.

SRAM Powertrain

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Comments

cooperquinn
+20 Sandy James Oates Dan Pete Roggeman Deltap60 Matt Cusanelli hotlapz XXX_er cxfahrer Cr4w Karin Grubb thaaad bushtrucker Ride.DMC Dave Smith Cam McRae TristanC DancingWithMyself bummel42 Kos bighonzo AlanB Bill T Seb_Kemp aztech Dogl0rd Cam R

Reminder that if you're not interested in ebike content, no one made you open this article.

Reply

Jotegir
+11 UMichael NotMeAtAll Dan rusm trioofchaos [email protected] 93EXCivic bushtrucker Cam McRae TristanC Tjaard Breeuwer

This comment has no effect on me because I can't read.

Reply

syncro
+2 Shoreboy [email protected] BarryW thaaad

When did NSMB start telling people what to read or say?

Reply

Jotegir

Ever since they started the cult of min max

Reply

syncro
+10 roil DanL Mammal [email protected] Jotegir Velocipedestrian BarryW TristanC BadNudes cornedbeef

If there's a cult to follow, that's the most worthwhile one.

Reply

DanL
+4 LWK Cam McRae Velocipedestrian thaaad

hahaha, this is one of the few times I have gone straight to the comments sections.

Reply

oldmanbike
+3 Cam McRae BarryW ZigaK Mario S BadNudes DancingWithMyself thaaad

Reminder that if you’re not interested in your for-now readers’ views, no one made you read our comments.

Reply

cooperquinn
+1 thaaad BadNudes Dogl0rd

I'll just copy/paste my comment from last week. :) 

If its any consolation, some of us contributors are non-motorized only (unless you include my cargo bike. Which, hopefully you don't? I think I draw the line at "is it replacing car trips" for whether or not I'm interested in an ebike...)

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mammal
+8 yardrec aztech Shoreboy Andy Eunson trioofchaos Skooks bushtrucker Dogl0rd

UGH

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shoreboy
0

I feel this one word sentiment sums it up well for me also.

SRAM is so far behind. Anyone remember the Autobike from the late 90's? This looks like it was filmed with a potato, but still a good laugh.

https://www.youtube.com/watch?v=u6-8kQCbTYA

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brad-sedola
+8 UMichael Jotegir Dan Jerry Willows Skooks Morgan Heater Cam McRae Hardlylikely

I'm an armchair e-biker. I don't own one, but it's just a matter of time. On the subject of integration, I don't think it will get much better than what Pinion offered up earlier this year with their MGU. Once electric integration started to be introduced with derailleurs costing north of $700 and dropper posts for$1000+, electric anything is out of touch for me. Since this system is targeting the premium crowd with premium pricing, I'm guessing $15k+. If I'm second mortgaging for that kind of coin, I'm going to opt for a system that doesn't require $700+ when I tear off a derailleur or $1k for cassette/chain/chainring replacement.

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Jotegir
+4 Brad Sedola Mammal Skooks Hardlylikely

I won't say "never" but I can't foresee a situation where I have a bike with electric anything shifting, transmission or no. I'm with you as far as crashes go,  but one thing I don't get is why anything but the top of the line ebikes are not just covered in deore 11 speed or equivalent. Heavy, long lasting cassettes on high torque bikes. Cheap replacements when things get chewed up.

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pete@nsmb.com
+3 Jotegir Cam McRae Hardlylikely

What you describe is what Shimano has done with LinkGlide. It'll be interesting to see what happens when the new Shimano Steps/LinkGlide-equipped systems come out and what companies spec at different price points.

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blaklabl
0

Only thing keeping me from Linkglide on my Levo is lack of MS interface - I have XTR hubs and they don’t make an HG freehub for it.

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cam@nsmb.com
+3 Velocipedestrian blaklabl Tjaard Breeuwer

That’s a little bit tragic.

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blaklabl
0

12 speed Deore cassette only lasts me about 600 miles on the Levo.

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xy9ine
+5 Skooks Jerry Willows Morgan Heater Mark Hardlylikely

yep. integrated gearboxes are the inevitable (not too distant) future. putting so much torque & additional milage through derailleur systems (especially ones so $$) is a not so great solution - and the drawbacks of meat powered gearbox bikes are generally addressed with the addition of angry pixies. if you're going to spend moto-like $$ on a bicycle, having similar levels of drivetrain robustness isn't too much to ask, i think?

(i'm not yet ready for an ebike, but hoping the tech has reached that point of evolution in a handful of years when i might start seriously thinking about such things).

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morgan-heater
+1 Ride.DMC

I'd love to have one for accessing back-country terrain for hiking/climbing/skiing, and quick big elevation days when my legs are feeling pooped. I'm not going to spend the money till there's a Pinion MGU + solid state battery + belt drive option though. Probably 5-10 years.

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UMichael
+8 roil Skooks bushtrucker Cam McRae DancingWithMyself MTBrent Dogl0rd Hardlylikely

I must be getting old, because I really dislike integration and interconnection.

I just want one thing to do one thing.

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DancingWithMyself
+1 Dogl0rd

Think the term people are looking for is psychological reactance.  I'd guess a huge portion of the mountain biking population, regardless of age, has it in spades.  I wouldn't buy that motor period, but being forced into an AXS reverb is a hard double no.

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NotMeAtAll
+7 UMichael Jotegir roil Skooks Morgan Heater XXX_er cornedbeef

It's a shame we are not making a push for manufactureres of bike motors to use the same frame interface. They tend to argue that the system is not compatible, the software will not function, battery and conectors are not standard, but even they are not willing to push for standard mounting package.

I also think sram and shimano are pushing too hard on the e-bike motor without gears that they will lose this market soon. I hope that brose, Rocky Mountain, Bosch, Bafang, Polini, Fazua, and others, catch that shift soon.

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roil
+5 UMichael Skooks Morgan Heater BadNudes Hardlylikely

Single provider ecosystems are expensive. I want more modularity for greater options, not less.

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andy-eunson
+4 Jerry Willows 93EXCivic FlipSide Hardlylikely

I look at what the automotive world has become and the added cost and complexity that drives people to lease so they can dump their hunk of crap before it becomes a money pit. My neighbours truck had some glitch that caused it to limit the speed to 80kph. Something to do with the diesel emissions system. A week at the Chevy dealer could not fix it. I call bullshit on that but after waiting six months they have a new truck. My own Ridgeline has had a number of issues too. New injectors on warranty, two rear view camera repairs and the all all wheel drive cost me five trips to North Van and about $3000 to repair not warranted. Now I get a transmission problem light intermittently. I hear about I think BMW in Europe going to a subscription model for certain features. Yes your car has heated seats but you have to pay monthly to use them. 

But as long as I can get a bike with mechanical components that I can mostly service at home I’m happy. I hope I’m smart enough to read between the lines of marketing drivel to avoid costly mistakes, but I’m not immune. I really don’t see auto shifting really being popular. In cars it’s getting hard to find standard transmissions because only enthusiasts want them and enthusiasts are by far a minority. Mountain bikers are almost entirely enthusiasts of the sport. 

I’m not for universal growing of the sport. I hear from North Vancouver friends that trails are pretty beat from heavy bike traffic. We need to have conversations about this growth now. People say e-bikes are the horse out of the barn and you can’t put it back. Let’s not wait for a local government entity to put that horse back in the barn by force and shove the bikes back in at the same time. 

Look at how camping and hiking have become regulated in many places.

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LoamtoHome
+2 SteveR DancingWithMyself

lots of bikers out there and very few people working on the trails unfortunately....

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SteveR
+1 DancingWithMyself

Unfortunately, that's not just a shore thing, Jerry.

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syncro
0

Unfortunately Andy, it seems most people are not interested in having those conversations. Suggestions of  separate trails for different activities and paid trail passes or user fees get dismissed. A core feature of the sport is that it is free and generally unregulated and I think most people don't want that to see that change. Eventually though, things are going to have to change.

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pete@nsmb.com
+2 Mark Andy Eunson tmoore Dogl0rd

Electronic/mechanical complexity, I'm with you, and I think it's a legitimate concern with e-bikes. I also generally like the idea of being able to fix my own bikes - at least some parts of them. We've gotten used to having suspension serviced by experts, for better or worse. E-bike service and maintenance has teething problems now but there will be service centers in future and it won't be as painful. But I still 100% understand why the maintenance/failure potential makes them a turn off for people.

I remember BMW's heated seat subscription imbroglio, but a 2-minute google search just gave me a lot of info: they floated the idea and then killed it due to consumer outcry, however in a way I don't hate the idea, depending on what heated seats would cost up front (in BMW's case - probably a lot). The theory was that they'd equip ALL Beemers with heated seats, and you could still pay for it up front as an option. But if you didn't want it, you could simply not pay for it when you buy the car, but if you change your mind, you could activate it later (so could the car's 2nd owner). The headlines tell you it's an insane money grab, dig a little deeper and you understand why they considered it. Other software-enabled (of course heated seats require hardware as well) options are already offered by subscription, such as remote start for Subarus. I'm not arguing for or against but it's a classic case of media/headlines obscuring the truth. 

More mechanization and automation isn't always good. I think that's your main point and I agree. Some of what we're seeing right now are engineering flexes. In Shimano's case, I said AutoShift felt like tech they engineered for use primarily by e-bikes used for commuting and touring (primarily non-enthusiast riders at least from the auto vs manual shift example from the car world). In SRAM's case I don't really know why they're bringing an Auto Shift function. Is it for racers? Problematic. Certainly not the average enthusiast rider. So, for newbies? Are those the people spending 10-15k on new e-bikes? 

Local governments won't close trails because of overuse - they WANT people using the trails. Trails are a public resource and important for public health. It's elitist to want to keep people off of them. It's not elitist to want to make sure people use them and treat the trails and each other with respect. More users will eventually = more trails. 

I don't understand your statement about camping and hiking regulations at all. There are legal places to do both - same for MTB. And as it is, MTB is tolerated in a lot of places where it is illegal. So far, I haven't heard of a single case of trails shutting down because of e-bikes. But mountain bikers as a general user group are certainly capable of acting like assholes and having trails shut down.

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andy-eunson
-1 cornedbeef

Pete: there are number of hiking places now where you need a day use permit like Garibaldi park. And camping is limited to certain areas and you need a booking and permit now. I don’t camp but I think there is some sort of lottery or booking system in place which gets sold out in short order when it opens in late winter or early spring. In the 80’s one could just camp anywhere. Yeah one can go across the highway to Brandywine Meadows and hike and camp anywhere. All I’m getting is that now is the time to talk about things. When I ride in Squamish in spring before our snow melts out I see a lot of riders on weekends. It’s popular now. Add motors and more people will be able to ride more often at greater distances each time they ride. Our politicians are all reactive and not proactive. Apparently to solution to the housing crisis is build more. Whoa whoa whoa. How about we also, at the same time, pump the brakes on immigration which is what is driving population growth in Canada. But no, we need growth to grow the economy forever because money. Anyway way off topic, but the growth and the possible negativity should be looked at now so we can plan for down the road.

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LoamtoHome
+3 roil Skooks Morgan Heater

SRAM can do lots of high tech but still can't make a 200mm AXS post?  

E-bikes for me are a ways away... Reliability/warranty for one and the current style of drivetrain makes no sense (pinion style ftw).

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DancingWithMyself
0

The post is ridiculous.  Reimagine hangers and redesign the drive train to set this up, but can't bother to make a post with enough drop.

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helpimabug
+3 roil Maximum Radness Mammal Mario S Hardlylikely lev3000 bikedrd

Hilarious effort spent on optimization of a fundamentally tortured design.

Ebikes are slow electric dirtbikes that have to pose as bicycles so they can sneak into the non-motorized vehicle trail infrastructure.  If you designed a real electric dirtbike you wouldn’t use a f@cking bicycle drivetrain.

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roil
+5 Maximum Radness Mammal Timer thaaad Mario S

A bit awkward for SRAM's business model.

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wingelabs
+2 Timer Konda

@Cam McRae

I'd like to hear more about this 6 magnet speed sensor. I'm sure SRAM are probably using it to help estimate where the cassette is at any given time after a shift is initiated, there are limited shift ramps on the cassette, so the system can probably guess when a shift has been accomplished/completed.

But that means they're they're getting 6 pulses to their hall effect sensor for one wheel revolution... which opens up a very easy way to trick this system into doubling your max assisted speed... you just drill out 3 of the magnets (or 5) and the system now thinks you're going half as fast (or 1/6th as fast). Its worth asking SRAM what they're doing to prevent this, as they probably need security systems in order to comply with regulation, and this seems like a very easy to bypass speed limiter

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cam@nsmb.com
0

That’s an interesting point. I wonder if there are sensors to defeat that sort of trickery. 

Once I’m able I’ll see what I can find out.

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Timer
0

Isn’t „easy to unrestrict“ actually a selling point for an e bike company? AFAIK, the only reason car an motorbike companies made it harder to soup-up their vehicles is that they wanted to sell the more powerful versions themselves. E bike firms can’t do that.

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syncro
+1 Skooks

All this expense/effort and it's still not a powered gearbox. Is that next years innovation to then sell even more bikes? If SRAM and Shimano are going heavy into the ebike market I honestly don't understand why they aren't going straight to powered gearboxes. It just makes so much sense in term of simplicity (no chain), the advantage of reducing unsprung weight in the rear and having no expensive deraileurs to smash.

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pete@nsmb.com
0

I have no inside info on this but if I had to guess, it would be that as global e-bike sales numbers become more predictable, it'll be coming. Shimano started work on AutoShift in 2018. I don't know how long SRAM worked on Powertrain but let's assume at least 2-3 years. Back then, e-bikes were prevalent in Europe but still not selling in big numbers in North America. It's possible both brands are working on gearbox tech now, but if they are, it'll be such a big departure from where they are now that I wouldn't be surprised if it was a 5-year plan at least - for SRAM - meaning more like 6-8 for Shimano.

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Ceecee
+1 Jotegir

Bro-suh before who'-suh. 'Simplicity'

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XXX_er
+1 Cam McRae

Its looks like a pretty good market entry into the full-power category against the EP8, so a  90nm motor with a 720 or 630 W battery is pretty squarely in the ball park, the artical seems more about the motor than the bike which at this point makes sense

i think where SRAM can beat Shimano in the E-bike game  is service ... as in actualy having some

its nice to  see an  e-bike artical  that actualy talks about e-bikes as oposed to sailing or various other wankings ... thank you

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maximum-radness
+1 Cr4w Mammal Dogl0rd

I love motor biking.

I love mountain biking.

I like that they’re different. 

I get that some of my Best Buds are all in on the motorized version of the latter. But I enjoy them both so differently that they are actually completely different activities at the highest level of performance that they both can be-and that I can afford on my reasonable salary. Electric moto is gonna be a game changer for that culture. Electrified bicycling has already changed the game for non electrified cycling at every level. 

But this meat powered acoustic bicycle enthusiast is wary of wild new Tech Guinea pigging me off my purchase, and will continue to watch from The sidelines for a while more. Meanwhile, this meatjuicingacousticahredding “all mountain” 170 trail bike is friggin insane compared to what we were riding 10 years ago…….

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kos
+1 Jotegir Morgan Heater thaaad

E-bikes are Satan's own spawn. With that out of the way... :-)

1. Two speeds = fail. Didn't Chevy leave that behind in the 60s with their two speed slush box?

2. Rally doesn't adjust low enough to allow tweaking for long, long days.

3. I'll wait for the Pinion motor/gearbox combo. They ought to have that well sorted by the time I buy my Satan's Spawn for my 70th b-day present to myself (six years, kids).

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Jotegir
+1 Kos

1. Two speeds = fail. Didn't Chevy leave that behind in the 60s with their two speed slush box?

Yeah, I'm with you on that one - especially because I don't think it involves substantially more parts outlay and could just be software if they designed their product the right way? I figure you want at least three modes on all e-bikes: a minimal, long range mode, a responsive-to-torque input mode that can vary in power from minimal to max depending on what the rider asks with their inputs, and a "give me everything you've got" mode.

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XXX_er
0

you know they drag race those 2 spd transmissions right ?

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andy-eunson
0

As in top fuel and funny cars? That’s a different way way way more robust tranny. I think it’s a Lenco tranny that they use for those monster engines. I think those are up to 8000 hp? More? I don’t think Teslas have a tranny either. 

It could be interesting to have an ebike with no gears and some form of pedal feedback to make the motor engage but then if the battery fails or you forgot to charge it enough you’d be hooped. And once over the predetermined speed limit you couldn’t make the bike go faster than that 30 kph limit.

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XXX_er
0

There are actualy  stock classes that use the 2 spd powerglide with some tricks and maybe  a high stall speed convertor to have the motor  really churning when the lights trip but they just race other stock classes with a 2 spd or have a handicap system so the guy with a 4spd might leave later than the 2 spd to make it look like a race but in any case its really all about the time 

there isnt really a whole lot of assist from an e-bike motor, I think in order to have an electric motor assist the rider you need those  12 gears OR you need a really big honkiing battery/ motor which is then way too big for the rider on a bicycle

this could change with a gearbox/ motor combo, so maybe there could be more power/ less gears , maybe a 9spd with a more robust motor using a belt drive  cuz i think E-bike motors are kind of stuck at 85-90nm becuz the  mtn bike drive train limits how much power you can reliably put thru that  drivetrain

That or from some of the ideas i am reading ... really good drugs

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tashi
0

How much does that bike cost?

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pete@nsmb.com
0

It's not released yet, but you'll know soon enough ;)

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craw
0

TBH I'm not surprised. Total integration with all the things makes sense. Who will be the first to incorporate all of this stuff with the Weagle pulley thing? I guess it will be Pivot so that means no XXL size forever because that's not a recognized type of human in Pivotland. Nonetheless I look forward to seeing it.

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mayberex
0

Dave weagle is a patent troll. His “DW Link” can be found in engineering dynamics text books spanning back to the 50s

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thaaad
0 DancingWithMyself BarryW

Do golfers who don't use a cart and choose to walk the course get mad at golfers who use golf carts in the same way that some mtb riders get mad at people who ride ebikes?

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cooperquinn
+1 thaaad

Yes.

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DancingWithMyself
+4 thaaad lev3000 Couch_Surfer BadNudes

Golfers are always angry.  Integral part of the experience.

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Vikb
-2 Maximum Radness Cr4w tashi Morgan Heater demo7_rider DancingWithMyself

Seems overly complex. An electric motor will happily go from 0-30kph without any gearing changes with all the torque required for trail riding. Get rid of the MTB drivetrain. Mid mounted motor with a chain to a single rear cog. You can keep the pedals/cranks if you want and just adjust motor speed based on rider foot inputs.  The result would be a lot less maintenance and cheaper to manufacture.

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earleb
+4 Skooks Jerry Willows Pete Roggeman Cam McRae

Try maintaining trail climbing speed at a human friendly cadence with a single cog and then come back and re-address the statement. 

Just like meatgrinder singlespeeding you'll always be in the wrong gear. The window of optimized gear will be wider, but it still won't be the right gear for most of the time. 

Now something like a wide range 8 speed would likely get to a point where you're in a pretty good gear most of the time.

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Vikb
0 Cr4w demo7_rider

You can maintain any speed you like with an electric motor [0-30kph or higher as desired] once you remove the physical connection between it and the pedals. You'd be pedaling by wire and the computer/control board would tell the motor what speed to spin. You don't need any gear changes at all. It's a well established use of electric motors. The difference in this case would be translating the spinning on the pedals into a control signal for the motor. That's trivial.

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syncro
+2 demo7_rider Bogey

But you'd need to have some sort of tension device connected to the pedals to make them effective and it would need to be variable to mimic different pedaling cadences.

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Vikb
-2 demo7_rider Bogey

Yes you need something applying drag to the pedals for feel and a sensor to read the RPM/force you are applying. That's trivial.

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syncro
+6 Jerry Willows Pete Roggeman tashi demo7_rider ogopogo Bogey

Trivial? You're talking about a mechanism that has no purpose than providing drag and will also require software and sensors. That seems like a lot of waste compared to building say a 3spd powered gearbox. What you're describing is completely removing the rider from the pedaling activity, which is strange considering your stance against mtn ebikes.

Vikb
0 Cr4w BarryW demo7_rider Bogey

What I am proposing is much simpler than the SRAM product being discussed in this article or an internal gear box hooked up to an electric motor.

I'm not commenting on ebikes in general. I'm not a fan of them, but if you are going to party with a motor on the trails it seems silly to waste the effort to replicate a MTB drivetrain when that is no longer required for anything, but Trail Theatre purposes.

The electric motor doesn't need any gearing changes to manage trail speeds so the only thing you need to do is get a signal from the rider to the ebike's motor controller telling it how fast to spin. This is not a hard problem.

syncro
+1 demo7_rider DancingWithMyself BarryW

So what you're describing is a motorcycle with a throttle - that's a very different activity than an ebike. I know a few people who went ebike because they wanted some help with the pedaling but didn't want a full on motorized bike. It's almost like you're advocating for people to go full on motorized - which seems odd.

skooks
+1 Cam McRae

You're still going to need to control the pedal rpm to wheel rpm factor. So still a gear change, even if it's done in software.

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earleb
+2 Mark Bogey

The torque density just isn't there in the current size of motors used. 

Now take the weight from a drivetrain and shift that into a bigger motor and change the motor over to axial flux and we could be getting closer to a singlespeed. 

The other catch with the single speed idea is that climbing will be at a lower rpm and possibly in a very inefficient range for the motor and draw more battery power. 

The beauty of gearing is that you know humans like to pedal between 80 and 90ish rpm in most situations and you can optimize the motor around this for efficiency. Clicking gears at the wheel allows the huge variation in torque to keep motor and human in this efficient range.

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tashi
+2 Cam McRae Bogey

The peddling input is still important to how the bike rides, even with the motor.

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Vikb
0 BarryW demo7_rider

Sure you can simulate a MTB drivetrain as much as you like if you felt that was important including faux shifting or you could have it work differently. Since it'll be run through a computer different riders could opt for different feels if they like and change whenever desired.

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tashi
0

You COULD, but your only stated reason for doing so is to eliminate complexity.  But your solution involves a fair amount of (unproven) complexity.

Or you could just use the existing drivetrains.

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Vikb
+1 BarryW Timer demo7_rider

I mean if you look at all the moving parts of the SRAM drivetrain being discussed here hanging out in the dirt and getting smashed then consider a few sensors mounted in the BB area with a thick chain running between two burly cogs, with no shifting at all, and don't see that as a simpler solution that's going to be cheaper and easier maintain...well I don't what to tell you.

The only thing the SRAM option has going for it is it looks familiar.

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tashi
0

I’m no mountain bike engineer so I suppose I’ll have to take your word for it.

morgan-heater
+2 demo7_rider Bogey

The range would be drastically reduced if you don't put your own power into the system. However, it would be possible to just use pedal power to charge the battery while the motor spins the cog. Probably a lot heavier though. I think the Pinion MGU approach is a lot better than your idea.

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Timer
+1 ogopogo

With improvements in battery and motor tech, this will become moot. 

As will many of the things that are bolted to current E-bikes in order to keep up the appearance of a bicycle.

In time, they might become simply motorbikes with some fluff in order to comply with a minimum of regulations.

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bogey
+1 thaaad

This is a key point that is being missed in the discussion - the primary power input of an ebike comes from the rider. The motor simply adds to it. If you take away the connection from the cranks to the rear wheel and add a resistance unit, you will drastically reduce the range. That’s a no-go for any ebike other than the throttle types.

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craw
+3 Mammal Mark ogopogo

That doesn't leave a lot of room for $700 cassettes and $900 derailleurs.

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syncro
0

That's also why SRAM and Shimano need to carefully consider how they push these technologies. I agree with Vik to a certain degree that deraileurs/cassettes are going to become irrelevant in short order when it comes to ebikes. IF, and this is a big if, ebikes become the dominant type of bike (mtn or otherwise) in the consumer market in the not too distant future AND they are gearbox types bikes (seems plausible) then the market for cassetts and deraileurs is going to evaporate as will much of their profit. There is potentially a huge shift coming in the bicycle market and imo investing in ebikes with traditional bicycle gearing systems is going to be a losing proposition.

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XXX_er
0

I supose one can spend 1600$ but I just refreshed my  complete  nx drivetrain for well under  300$ and i found an NX der at MEC for well under 200$,  i  don't have to worry about a little extra  weight  cuz  85nm of power and you probably want better wearing steel parts

sure the motor& gear box is coming but when/ how much, how many gearboxes can pinion   supply ? 

regular bikes are not going to disappear overnight.

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BarryW
-2 Maximum Radness ogopogo DancingWithMyself thaaad Bogey bikedrd

Politely noting that this belongs somewhere other than 'North Shore Mountain Bike'

Probably more like 'North Shore Motorcycle Bros'. 

Noting my dislike for the motorcycles on the trails and media platforms pimping them.

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XXX_er
+2 thaaad Kos Andy Eunson Hardlylikely

" Reminder that if you're not interested in ebike content, no one made you open this article."

posted in the first line of the comments and still you show up to wank on the e-bike articals and you are not being polite

just noting my dislike for  impolite wankers

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