SRAM Red eTap - actual weights and installation
Wireless electronic group slots between mechanical Red 22 and Shimano Dura-Ace Di2 9070
This article originally appeared on BikeRadar
SRAM Red eTap, the world’s first wireless road shifting group, is now beginning to trickle out and BikeRadar has received a test set. We have already posted complete details on the group, and compiled the initial impressions of four testers. In this post, we’ll show you how claimed weights stack up against company claims, and highlight the critical steps for installing and adjusting the electronic group.
As we get more time on the group, we will update our 4.5-star review with more impressions and photos.
We are testing the group on a 2016 Specialized S-Works Tarmac
SRAM Red eTap actual weights
The SRAM Red eTap group shares some componentry with the mechanical Red 22 group, namely the cranks, chain and brake calipers. You can see those weights in our review of Red 22.
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.
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Claimed weight for a pair of eTap shifters is 130g and we weighed our test samples at 131g. For reference, mechanical Red shifters are 140g a piece.
The rear derailleur is claimed at 239g; we weighed ours at 237g including the 24g battery. (Note that the photos show the derailleurs without batteries but with the red plastic travel covers that weigh 3g.)
Derailleur shown without the battery
The front derailleur is claimed at 187g; we weighed ours at 162g including the battery.
The electronic derailleurs are heavier than their mechanical counterparts, but the group makes up some ground with the absence of cables and housing.
How to install SRAM eTap
The shifters and derailleurs mount on the bike just like mechanical pieces. The difference comes in how they're connected to each other; instead of running cables, you need to pair the pieces electronically.
Setting the reach adjust for the eTap levers is easy. There are four indexed settings that you set with a 2.5mm Allen wrench on the outer side of each lever body underneath the hood cover.
eTap offers four indexed reach settings, which control the lever's distance to the bar
Each eTap component has a function button and a single LED light. This button serves initially to pair the group, then later to make micro adjustments or, on the derailleurs, to shift with the bike in a workstand.
You begin the pairing process by holding the function button on the rear derailleur until its LED flashes. Then, you hold the function button on the front derailleur until the LED on the rear flashes quickly. Now these two are paired.
The function button on each eTap component serves a few purposes
The process is repeated for each of the shifters, holding their respective buttons until the rear flashes quickly. Now the system is paired.
To set the outer limits of the rear derailleur, you first use the electronics then the ‘old fashioned’ limit screws. Holding the function button while shifting with a lever makes a small adjustment to the rear derailleur. As with the shifting protocol, the left lever moves the derailleur inboard; the right lever moves it outboard. So, with the derailleur shifted all the way inboard (to the largest cog), you use the left lever to adjust the derailleur in until the pulley wheel is in line with that cog. You repeat this process with the derailleur under the smallest cog, micro adjusting it with the right lever.
Holding the function button while shifting micro adjusts the rear derailleur. As with shifting, the left lever moves inboard and the right moves outboard
Then, you set the limit screws as you would a mechanical derailleur. SRAM master mechanic Nate Newton suggests setting the B knuckle adjustment between setting the inboard and outboard adjustments. He recommends using an Allen key between the pulley and the largest cog to easily measure the proper adjustment (between 6-8mm).
The front derailleur is a strictly mechanical affair for the limit screws. Note that the top 2.5mm screw is reverse threaded while the bottom screw is normal.
Note the reverse threading on the top screw
The front derailleur has the same marks that current Red derailleurs do: a gray zone for height adjustment relative to the big ring is shown on the inner plate, and lines for alignment with the big ring are found on the top and rear of the cage.
One final add-on is a bracing wedge that can be affixed to the back of the front derailleur. Coming in three sizes, this plastic piece wedges in between the derailleur body and the seat tube. It is designed to prevent flex in the system and ensure clean shifting.
The triangular wedge bolted to the back of the derailleur is designed to reduce or eliminate flex in the front shifting system
At the risk of stating the obvious, it is worth noting that, unlike Shimano and Campagnolo’s electronic system, there are no wires connecting the shifters to the derailleurs and a battery. This speeds up the installation process tremendously and results in a cleaner build. The exception is the Blip remote shifters; those are plugged into ports on the shifters.
How to maintain and adjust SRAM eTap
As there are no cables to stretch or get contaminated, the system should not need adjustment over time.
Should you need to adjust the rear when swapping in another wheel — or if you crash — then you use the micro-adjust protocol of holding the function button on the shift levers to move inboard or outboard. This can be done while riding or with the bike in a workstand.
Green means good battery life. Red means less than 25%. Flashing red means less than 5%
The interchangeable derailleur batteries do need charging. SRAM claims a 60-hour battery life, which could last between 1 and 6 months. The LED light shows green until battery life dips under 25%, at which point is shows red. The LED starts to flash red when battery life is below 5%.
After releasing a safety switch, the batteries slide out easily and into a charger.
The shifters use standard CR2032 coin batteries, with the same LED indicator system. SRAM claims these will last about two years.
When traveling, SRAM recommends removing the batteries and attaching plastic covers to the derailleurs and batteries. The system works on accelerometers; the system is put to sleep when immobile then woken when moved. So, if you transport your bike by car or plane without removing the batteries, then the system will be awake the whole time.
We will be putting the system through its paces in Colorado over the coming weeks, riding in the cold and wet (and hopefully some warmth), and reporting back with an updated review soon.
