what is etap bike?
A road bike with etap has neither gear or electric cables. That's right, SRAM etap works wirelessly. A road bike with SRAM etap is therefore particularly tidy. Above all, however, the new technology brings previously unknown precision to your road bike. A road bike with etap doesn't have to be expensive either.
If we're honest, there isn’t a bad electronic groupset that we know of, they all shift from cog to cog with lightning-quick speed and accuracy — if they are set up properly — and require minimal upkeep except for keeping things clean, charged and lubed, and replacing moving parts as they wear out.
With that, choosing between a Di2 and eTap groupset is becoming increasingly difficult, with each system have its strengths and weaknesses. Below are the factors we would use when it comes to choosing the right road bike groupsets.
Both SRAM and Shimano have different commands for moving the gears up and down the cassette and chainrings. Shimano was the first of the big three-component brands to introduce electronic shifting, although Mavic beat them to the punch way back in 1992 with the now discontinued Zap group.
The layout of the Di2 shift buttons almost mirrors its mechanical shifting; two small shift buttons are situated just under the blade of the brake lever. For experienced riders, and those who have spent any time using a Shimano equipped bike, the transition to Shimano Di2 will be seamless and intuitive, and shifts are met with a tactile click. The only minor criticism we have of the Di2 shifting layout is that with thick gloves on, it’s hard to feel the difference between the buttons.
When SRAM launched its first electronic groupset, it came at the shifting problem with a clean slate. Instead of mimicking the DoubleTap system used for its mechanical groupsets, the brand opted to make the right paddle shift to a harder gear, the left paddle shift to an easier gear, and both at the same time shifts the front derailleur. This layout is extremely intuitive, and there has been plenty of reporting on how easy this system is to explain to beginners or inexperienced riders. The trouble with this argument is, beginners and inexperienced riders are likely shopping well below the price bracket of an eTap or Di2 equipped bike.
Both systems have some degree of autonomous shifting; as you move up or down the cassette, the groupset will shift at the front to prevent overlapping gear ratios — Shimano calls this Synchronized (Syncro) shifting, and SRAM calls it Sequential Shifting. Both also have semi-automatic versions which will shift a few cogs up or down and the rear as you change at the front to prevent jumps in gearing.
When it comes to shifting speed, as in how quickly each group moves the chain to the next cog, Shimano has the slight edge here, but we are talking fractions of seconds. This is likely due in part to the fact that eTap has to wait a millisecond to see whether you are just pressing one shift paddle or both.
eTap is entirely wireless, so each component needs to have its own battery, while Di2, with its wires, can run everything off one single battery housed in the seat tube.
eTap uses disposable coin cells in the shifters, and rechargeable batteries in each derailleur. As each derailleur has it's own battery pack, visually they aren't quite as svelte as their mechanical or Shimano compatriots. SRAM says the shifters should have juice for about two years, depending on use, while the eTap batteries will need to be charged after about sixty hours of ride time, again depending on how much you shift. Typically, the battery on your rear mech will die first because that’s where the most shifting happens; if you do get caught out, you can always swap in the battery from your front derailleur to get you home.
Shimano’s Di2 battery is claimed to last about 2,000km between charges, depending on usage. When your Di2 battery does start to go flat, you will lose front shifting to preserve enough power to get you home before your bike is converted to a single-speed.
Having spent quite a bit of time on both systems, I have found myself caught out more times with a dead battery with Di2 than eTap. The battery lasts such a long time, I simply forget it’s there until the front derailleur stops working, whereas the comparatively short battery life of the eTap batteries is a blessing in disguise because you’re unable to forget they exist.
With the latest eTap groupsets, SRAM added a 12th cog to the rear cassette, and with it, a new approach to gearing it called X-Range. This new system traded the traditional gearing combinations for smaller chainrings and wide-range cassettes.
Based around a 10t small cog, the new eTap 12-speed cassettes come in 10-26T, 10-28T, and 10-32T ranges which work with the standard eTap derailleur. SRAM just launched it’s new wide gearing 10-33T and 10-36T will only work with the new Max AXS rear mech. If you want to go super wide range at the back, the eTap AXS road components speak the same language as the Eagle AXS MTB components and can be mixed and matched. At the front chainrings are available in 46/33T, 48/35T and 50/37T. At the Red level, the chainrings are a single piece, which may reduce weight and improve shifting, but when you wear one out, your wallet is going to take quite a hit — especially if you have the chainring integrated Quarq power meter cause that will need to be replaced too. The Force crankset and power meter are a more standard layout.
The new Force Wide sees lower gearing and a 43/30T crankset but also pushes the chain line out to 47.5mm from 45, improving clearance for gravel tyres and compatibility with mountain bike bottom bracket standards.
With the Orbit Fluid damper in the rear derailleur, you can run 1x gearing from 36T to 48T.
Shimano’s gearing is a bit more traditional, with 11 cogs at the back and cassettes ranging from 11-25T all the way up to 11-34T in the Ultegra spec, though you’ll need a long-cage derailleur to access the wider gearing, both for the second-tier Ultegra Di2 group, and Shimano's GRX gravel groupset.
The chainrings come in 53/39T, 52/36T, and 50/34T options all which have the same four-bolt layout and are interchangeable.
Both electronic drivetrains come in rim and hydraulic disc brakes, and both work pretty darn well. At the levers, both SRAM and Shimano offer reach and bite point adjustment, and road-specific disc rotors in 160mm and 140mm sizes.
Shimano's rim brakes seem to have a stiffer caliper than SRAM’s and offer a bit more power and modulation. SRAM also doesn't make a direct mount rim brake.
SRAM hydraulic brakes are best known for their sizable master cylinder at the hoods. The early versions of SRAM hydro brakes were pretty ugly, but the skyscraper of a master cylinder did give you something to hold onto when things got spicy. The eTap hydraulic levers are still noticeably taller than their Shimano counterparts, but the aesthetics have improved tenfold.
Shimano has done a fantastic job of hiding the master cylinder in its hydro brakes, and ergonomically, they are pretty darn close to their cable-driven stalemates. The brake pads on Shimano disc brakes sit a bit further into the caliper when the pistons are retracted, so there is more clearance between the rotor and the pads as you roll along, meaning there's less noise from road grit that gets picked up by the rotor or a disc that's come out of true.
While they take a different form, both brands' brakes work, offering oodles of power and modulation. They feel different, but which is best for you will come down to personal preference, and over time you will get used to whatever is bolted onto your bike.
The main advantage of electronic drivetrains is that there are no gear cables to gum up or snap. With more of the best road bikes moving towards entirely hidden cables, this means less time trying to fish cables and housing through frames, handlebars and stems.
One of the main advantages of SRAM’s eTap system is that it’s wireless, meaning setting up derailleurs is pretty much as simple as bolting them on. You still have to run brake hose/cables and housing, though for hydraulic discs you will probably only ever need to do it once when building the bike.
With Shimano Di2, you will still have shift cables and junction boxes to contend with, but unless you are building up a frameset, this will be taken care of before your bike leaves the showroom floor.
Just about every electronic nowadays has some sort of connectivity for firmware updates, diagnostics, and customization. In this department, SRAM noses ahead of Shimano because each eTap compound speaks Bluetooth, and can be accessed through the SRAM AXS app.
To make a wireless connection to a Di2 drivetrain, you’ll need to purchase an E-Tube Wireless D-Fly unit, which connects to the E-Tube phone app; or you can plug a USB cable into the charging port for a wired connection to a Windows-only desktop application.
With the ~three-year product cycles we see with componentry in the bike industry, we would hazard a guess that the next Shimano road groupset launch is due in the next year or so, and we would also say it’s a safe bet that Bluetooth connectivity will be integrated.
Beyond the Syncro shifting and Sequential Shifting we talked about at the top, another advantage to electronic drivetrains is the ability to add satellite shifters. Whether it be the ability to shift from the tops or the drops without moving your hands, SRAM and Shimano both offer this functionality.
SRAM calls it satellite shifters Blips, these are round buttons which are wrapped under the bar tape and plugged directly into the shifter.
Shimano has a range of satellite shifters, from sprint shifters found in the drops, to climbing shifters which can be zip-tied to the tops. The top of the hoods also have a hidden button, which can be programmed to interact with lights and computers via ANT+.
When SRAM added a cog to its rear cluster, the cassettes, chainrings, and chains were no longer interchangeable; not only with Shimano components but the vast majority of third party offerings from brands like FSA, KMC, Praxis and the like. The 10T cog also means the brand swapped from the traditional HG freehub body to an XD-R driver. Friction testing has also shown the new Flat Top chain is a bit slower than a traditional chain, though longevity is said to be increased.
With that said, AXS components are cross-compatible, so if you want a 10-50 rear cassette and a 48T front chainring, you can bolt an AXS eagle rear derailleur on and pair it to your Force AXS or Red AXS shifters. With the Orbit Fluid Damper, which performs the same task as a roller bearing clutch, the same rear mech can be used for both 1x and 2x setups. The new DUB bottom bracket also vastly improves frame compatibility.
Shimano, on the other hand, uses a standard 11-speed chain, the HG freehub body, and you can swap in pretty much any chainrings you’d like — we do wonder if the next generation of Shimano drivetrain components will use the Micro Spline freehub if they make the jump to 12-speed.
I thought it was a great time to take a look at how SRAM's eTap AXS electronic shifting components stack up against Shimano's Di2 product line. Here are my thoughts on the pros, cons, and how to choose between the two brands.
Shimano's Di2 (pronounced "dee-eye-two") was launched way back in 2009. That generation of components is obsolete now, but the name - digital integrated intelligence - lives on in the current Dura-Ace and Ultegra Di2 groups, and recently become available in GRX, Shimano's dedicated group for gravel, adventure, and cyclocross bikes as well.
AXS (say "access") from SRAM is far newer, only hitting the market in 2015. SRAM beat Shimano to the punch, however, with the wireless portion. When this article was written, Di2 was wired - in August, 2021, Shimano announced that their new Dura-Ace and Ultegra groups would be wireless, as well as moving to 12 speed. I've left the remainder of the original article online, below; you'll notice it refers to wired Di2, which is accurate regarding the product on the market today, but will be obsolete when the new wireless Dura-Ace and Ultegra hit the market in October.
The most obvious difference between Di2 and eTap AXS is the wires (or lack thereof.) Shimano's Di2 groups connect the derailleur(s), shifters, and battery pack together with wires. You may not see them, because on higher-end bikes the wiring and battery are typically hidden inside the frame tubes, but they're in there. This means when setting up a new bike, you need to get the correct length of wiring, and then route those wires through the frame, which adds complexity and time. Because there is only one (rechargeable) battery, the entire system charges at once when you plug into the charging port.
SRAM's eTap AXS components, in contrast, are wireless. The derailleurs and shifters each contain their own battery, and the connection between them happens over an encrypted, wireless protocol. There are no wires to route through the frame, which simplifies setup. That does mean, however, that you need to manage each battery independently - four in total, if your bike uses a front derailleur. Each derailleur has a removable, rechargeable battery that can be charged independently, while the shifters use disposable CR2032 coin-style batteries.
Remember that we're only taking about wireless or wired shifting, which is exciting - no cables to stretch or become contaminated with dirt, affecting shifting performance. Your brakes, however, must still be connected by hydraulic lines and filled with brake fluid. So while wireless may save you time, from not having to route wires through your frame, you'll still need to route the hydraulic lines, on both Shimano and SRAM systems.
Shimano offers more configuration options than SRAM. On an eTap system, clicking the button on the right shifter switches to a harder gear, while the button on the left shifter switches to an easier gear. On bikes with double cranksets, hitting both buttons at the same time moves the chain between the two chainrings. Shimano shifters have up and downshift buttons on both sides of the bike, so the user can manage the up and downshifts in a more traditional manner, as users might remember from mechanical shifting bikes they owned previously.
Shimano also offers a configurable option called Syncro shift, for users who want wide-range double cranksets but the simplicity of up and down shifting with one hand. In this mode, one button press can signal the rider's intentions, and the system can shift both the front and rear derailleurs at the same time, automatically. Clever.
SRAM eTap AXS wireless road components use the same 12 speed cassettes as their Eagle AXS mountain bike group. For cyclocross and gravel riders, this creates some interesting drivetrain choices and possibilities, because the components are cross-compatible.
Shimano, in contrast, sticks with 11 speed cassettes for the Dura-Ace, Ultegra, and 105 groups, even though Shimano's enthusiast-level MTB components are now 12 speed. This means that there is minimal cross-compatibility between the road and MTB components.
Shimano's Di2, because it has no radio transmitters or receivers to power, has a longer battery life than eTap AXS. On an eTap AXS system, the radio functions consume battery life. Although the batteries still last a very long time, the battery life is still much shorter than on a Di2 system.
SRAM claims about 600 miles (1000 kilometers) for the eTap AXS system, while the published lifespan on Di2 is double or triple that. In reality, the battery life on both systems is so long that even serious distance riders likely never need to charge more than once a week.
Because the eTap system uses separate, hot-swappable batteries on each derailleur, it's possible to simply carry spares on a long trip - for example, on an extended gravel backpacking trip where you don't have access to charging. That's not possible on a modern Di2 bike with internal batteries that can't readily be hot-swapped. But keep in mind with Shimano this is likely a moot point, since the battery life is so long in the first place there's no need for spares.
Note that eTap ASX shifter levers use separate, disposable coin-type batteries that can't be recharged. Having one of those die on an extended trip is very unlikely, but it might be a good practice to carry spares in your tool kit, just in case.
One of the most interesting parts of the SRAM eTap Rival AXS announcement was the crank-based power meter from Quarq. It's cleverly hidden inside the "DUB" crank spindle, and I was impressed by how low the upcharge is to upgrade to power monitoring when buying a Rival eTap AXS group or Rival eTap AXS-equipped complete bike.
The power meter is not offered on the traditional GXP cranksets, however, so this won't work on your bike if you have a traditional English threaded bottom bracket - an oversized BB30 / PF30 etc. shell is needed.
It's not surprising that setup and maintenance of electronic shifting would happen in a mobile app. Electronic shifting clearly appeals to a younger, early-adopter crowd who is comfortable with smartphones and an app ecosystem.
SRAM's AXS app allows you to do common tasks, like firmware updates, system setup, checking the battery charge, etc. from your iPhone.
Shimano's E-Tube Mobile app performs similar functions, but it's worth noting that it requires a bluetooth module on the bike - which isn't normally included with road groups, although it can be added.
At the top-end of SRAM's product line, we find the Red eTap AXS group, which competes against Shimano's Dura-Ace Di2 group. One step down we find SRAM Force eTap AXS and Shimano Ultegra Di2. Historically, SRAM's Rival (mechanical shifting) group has competed with Shimano's 105 group, which also used mechanical shifting - no electronic option on either of those groups. That changed, however, when SRAM introduced their wireless, electronic Rival eTap AXS group - Shimano does not have a Di2 electronic option at the 105 level.
I expect Rival eTap Di2 to be very popular as the OEM equipment on complete bikes from major brands, since it's the only electronic group available at this price point. Specialized, Trek, Ridley, Colnago, and many others have already announced spec and pricing. You can expect to pay from $3,000 to $5,000 for off-the-shelf bikes equipped with Rival eTap AXS.
If you're shopping for a grouppo to outfit a frame and fork you already own, expect to pay $1,200 - $1,600 for SRAM's Rival eTap AXS, depending on whether you want a 1x or 2x drivetrain, and the power meter option.
Shimano's wired Di2 offers amazing shifting quality, but there's no question that making it wireless would simplify setup and assembly. Shimano's patent filings suggest a wireless, 12 speed Dura-Ace Di2 group could be in the cards, but keep in mind, Shimano has many patents and R&D projects that don't necessarily become real products offered to the public.
The move toward wireless shifting means that frames and forks can change, as well. We're already seeing frames designed specifically for wireless - entirely lacking shifter cable routing ports. If your next dream bike is wireless-specific, the choice may be made for you.
Let's get this out of the way - Shimano's Di2 and SRAM's eTap AXS products are both excellent, and you can't go wrong with either. Dura-Ace and Red are pro-level components that have proved themselves on the World Tour, and an amateur cyclist would be lucky to have either. Ultegra and Force offer 98% of the performance at a fraction of the cost for enthusiasts who want more bang for the buck, and with the introduction of Rival eTap AXS, there's now a budget option for price-sensitive riders who want to jump into electronic shifting that didn't exist before.
That being said, there are some specific factors that might steer a rider toward Shimano or SRAM:
eTap is the name of SRAM’s proprietary electronic drivetrain for bicycles — the first truly wireless electronic shifting system and the heart of its RED eTap road group. Shift signals are transmitted and received via SRAM’s fully wireless protocol known as Airea.
The system, brought to market by SRAM in 2015 and used in a stage win that year in the Tour de France, is now available on several higher-end consumer bikes and, will, we suspect, eventually be used on less expensive models as well.
SRAM’s eTap system offers many welcome features, one being that it’s easy to install and tidy on the bike due to the absence of wires and cables. Better yet, buttons on the shift levers permit riders to make micro-adjustments to chain positions on the fly. Additionally, eTap allows the placement of small satellite shifter buttons called Blips anywhere on the handlebars or aero bars. There’s even a remote shifter called a BlipBox available that permits shifting both derailleurs in both directions with one hand.
What’s more, eTap’s front derailleur functionally can best be described as “smart.” As SRAM explains it, “Depending on which gear you’ve selected on the rear derailleur, the eTap front derailleur will vary how far it initially moves the chain before settling in a moment later to its final position relative to the chainring selected.”
Early on, some cyclists were concerned that other transmissions in the rider’s area might interfere with wireless shift systems (a problem that did affect the first couple of wireless computers I purchased), or that shifting could even be hijacked by miscreants. SRAM, however, extensively tested the system using hired hackers who were unable to take control of it. And eTap performed just fine at the Tour de France, where the surrounding broadcasting equipment had no impact on the system’s functioning.
SRAM also offers a hydraulic disc-brake version called SRAM RED eTap HRD. Its brakes make use of a hydraulic lever design with both lever reach adjustment and lever contact point adjustment, which is a first for road disc brakes. That group, purchased aftermarket to install on your existing bike, will set you back nearly $3,000. Without the hydraulic brakes, expect to spend about $2700 for the groupset.
Since 2016, RED eTap road groups have been available as standard components on some high-end bikes from several manufacturers, and we offer a sampling below. All have 11-speed rear cogs and 2 chainrings. To keep the comparisons somewhat comparable, all the models we looked at have rim brakes rather than disc brakes. (For that reason, we did not include the Trek Madone, which apparently puts only disc brakes on its current models that use eTap.)
There’s a lot to like about these bikes except for one really big sticking point — the price. But even if you don’t want to drain your bank account and buy one, it’s sure nice to look at them and dream, isn’t it?
https://www.nytro.com/bmc-teammachine-slr01-one-red-etap-road-bike.html
Swiss bicycle maker BMC says that one reason this ultra-lightweight premium carbon machine is so fast is its use of asymmetrical tube shapes that deliver a superior ride experience and a competitive advantage. It features TRP T980 direct mount brakes and a DT Swiss PRC 1400 SPLINE 35 carbon wheelset. If you’re racing on the Teammachine and not leading the pack, it’s not the bike’s fault. It can be yours for about $9,000.
https://www.cannondale.com/en/USA/Bike/ProductDetail?Id=66afc8a5-91bc-441c-ba20-e05ca570fb71
Available for about $8000, this U.S.-branded, race-proven bike is lightweight, stiff and aerodynamic. Made from BallisTec Hi-MOD full carbon, the SuperSix is designed to maximize your power and speed in every race.
https://www.canyon.com/en-us/road/ultimate/ultimate-cf-evo-10-0-ltd-us
This bicycle’s German maker describes the Ultimate CF EVO 10.0 LTD as “a bike with no compromises,” and it brags about it being both super light and durable. “This isn’t the first bike ever produced to hit these sorts of lightweight numbers,” its maker says, “but it’s the first you’ll be able to feel confident won’t break the very first time you skid out on a sandy corner or pack it for a vacation in the mountains.” That said, its pedigree is racing, and it’s intended to be a competitor. Sells for about $8,500.
http://www.bianchiusa.com/bikes/road/extreme-racing/oltre-xr4-red-etap/
Bianchi’s patented CounterVail frame technology — an integrated vibration cancelling system that’s imbedded within the layup of this high-performance bike — is arguably the most advanced comfort enhancement in carbon-fiber frames, giving it excellent stability at high speeds, mountain descents, and fast corners. Bianchi says the CounterVail construction reduces muscle fatigue; allowing the rider to hold an aero position during long periods of time. Used by the Dutch team at the Tour de France, this bike typically sells for about $10,800.
https://www.specialized.com/us/en/s-works-tarmac-etap/p/115701
This all-around race bike has been proven in Grand Tours and World Championships. Specialized, a U.S. manufacturer, uses its trademarked Rider-First Engineered design that applies specificity to every tube size and carbon layup for every frame size, thus creating the optimal balance of rigidity, weight, and responsiveness, so every frame, regardless of size, performs just as intended. The full carbon fork with tapered construction provides front end stiffness and steering response for instantaneous accelerations and high-speed descents. Sells for about $12,000.
https://www.giant-bicycles.com/us/tcr-advanced-sl-0—red-2018
As far as rim-braked models go, Giant offers two with RED eTap in its 2018 line up: this TCR Advanced SL 0 and the Liv Langma Advanced SL 0, which is essentially the same bike but in a women-specific configuration. Built on the lightest road frameset ever produced by Giant, the SLs boast what the company describes and an “unrivaled” stiffness-to-weight ratio for pure speed and efficiency. Both models include SRAM’s Quark crank power meter. Available for $9,900. Giant also offers disc brake models with RED eTap.
https://www.bikebling.com/Orbea-Orca-M11i-PRO-Road-Bike-2018-p/orbea18-orca-m11ipro.htm
SRAM Red eTap, the wireless 11-speed road group, will be available sometime this spring. If you want to dig into the details of the group, or the thoughts of four testers who have ridden it, we have those stories below. If, however, you just want the highlights, here we present nine critical things you should know about the groundbreaking group.
Free of shifter cables and featuring only a single paddle shifter on either side, the Red eTap levers offer great ergonomics. With your fingers wrapped around the hoods or the drops, you can easily shift with just a knuckle. This is great for shifting while out of the saddle; whether climbing or sprinting, you can keep your fingers close to the bar, and just reach out slightly with a knuckle to shift.
Shimano Di2 features two buttons per lever with a stock configuration identical to mechanical Shimano. While critics contend that this can lead to mis-shifts with cold, gloved hands or over rough terrain, it also means your left hand can shift the front derailleur both ways and your right hand does the same for the rear.
With Red eTap, you need both hands on the bars to move the rear both ways or to move the front at all. This isn’t a big deal, but something to keep in mind before you head off on a short errand with a cup of coffee in your hand.
If you sneak up on an unsuspecting eTap group and ever so gently touch a shifter without moving the bike in the slightest, nothing happens. The group is sleeping. Accelerometers in the derailleurs wake the group at the slightest movement and keep it awake for a time even when still. When you are riding, it’s always awake.
This auto-pause feature allows for a longer life (a claimed 60 hours or 1,000km) with the 24g battery.
The eTap group as a whole is about 1,970g, roughly 60g heavier than mechanical Red but about 75g lighter than Shimano Dura-Ace Di2 9070 for comparably configured setups.
Most cycling computers do their wireless communication on ANT+, whether for heart-rate straps, power meters or speed sensors. A distant but gaining second for wireless communication in cycling is Bluetooth, primarily for tethering to smartphones.
SRAM eTap uses neither of these, instead relying on a proprietary wireless language to ensure a closed system. However, eTap does speak ANT+; look for integration with Garmin Edge computers in the near future for things like gear-indicator and battery-life graphics.
Primarily used for maintenance, each derailleur has a function button that does multiple things. On the rear, pressing the button once shifts it outboard. Two quick presses moves it inboard. On the front, pressing the button once moves the derailleur to the opposite ring.
SRAM hasn’t yet announced whether individual batteries will be sold to be used as a backup (we could see tucking one in a saddle bag), but you can swap them between derailleurs. With Shimano Di2, when the main battery gets close to dying, the front derailleur stops working and you have 100 or so shifts left in the rear. This is okay — unless you’re in steep rolling hills or the mountains.
While stopping your ride to switch batteries and thus chainrings isn’t exactly ideal, it could make a lousy situation a little bit better. (At this point SRAM would point out that light indicators give you plenty of time to realize that it’s time to recharge the batteries before you stranded yourself.)
Okay, it’s not the only group with a power meter; you can also get SRAM Red mechanical with the spider-based Quarq. And, sure, you can get matching power meters now to go with a Dura-Ace Di2 or even Campagnolo EPS group, via Stages or Power2Max. Nonetheless, the fact remains that SRAM eTap is the only electronic group you can buy direct from the company with an integrated power meter.
