Bike Build Story: In the third part of our build story (here part 1 and part 2) we focus on the drive. We opted for the version with one chain ring - the SRAM XX1 Eagle. How we came to the decision and what special features the individual components have - you can find out in the article.
The question of the right drive for a mountain bike is inseparably linked to the question of the right gear ratio and the decision: How many chainrings can there be? While ten years ago it was still normal for hobby riders, amateurs and professionals to ride almost exclusively with three chainrings and finely graded cassettes, over the years there has almost been a kind of paradigm shift: more rear sprockets, a larger range of cassettes and fewer chainrings front. 3-speed cranks are now reserved exclusively for trekking and after two chainrings were almost exclusively used in the XC sector for a long time, more and more riders are relying on the simplicity of a 1-speed drive - even in the professional sector.
The decision - whether single or double - also brings an additional explosiveness, as it is also a decision between the two drive giants SRAM and Shimano. While at SRAM the derailleur was symbolically buried two years ago, at Shimano the meaningful philosophy 'There's no single truth' is being pursued. Although both manufacturers offer drives with one or two chainrings, you don't hide which direction you prefer.
The 1-speed rock started rolling a few years ago with SRAM's introduction of 11-speed drivetrains with wide-ranged 10-42 cassettes. Part of this innovation was also the new freewheel standard XD, which allows the small 10 sprocket to be installed, which would not fit on a normal standard freewheel. The great success of the XX1 11-speed group and the further expansion in the portfolio to the inexpensive GX group showed that a nerve had been struck here. However, the drive innovation did not come without criticism: The range was larger than anything that could previously be achieved with a chainring, but still no comparison with an established 2-speed drive. In addition, the racers in particular were bothered by the larger gear jumps.
It took some time, but SRAM reacted to the criticism - and how: With the Eagle drives there are now 12 sprockets on the cassette and with the range of 500% you finally enter spheres that could previously only be realized with front derailleurs. However, the second major point of criticism from many drivers remains: the gear steps tend to be somewhat larger - whether this is relevant in practice, however, depends very much on your own driving style and individual requirements. For comparison: The average gear jump of a 2×11 drive with 11-42 cassette is - after eliminating the redundant translations - at about 11%. With the SRAM Eagle, on the other hand, it is 14,6%.
At a glance: Pros and cons of SRAM Eagle
Pro
- Intuitive shifting, no danger of chainsuck
- Less leverage on the handlebars
- Clean optics
- Quieter drive, no chain slap
- lightness
Contra
- Bigger gear jumps
- Minimally smaller bandwidth
- Expensive wearing parts (cassette)
So there are definitely good reasons for using an Eagle drive in the XC area, or on our XC hardtail. In our case, the intuitive operation and the reliable function - regardless of the weather - were decisive. In the heat of the moment, with a 180 pulse and at the end of your strength, it is definitely a relief to only have to operate a gear lever. In addition, the danger of a chain jamming drops to around 0, especially in muddy conditions.
SRAM XX1 Eagle : The rear derailleur
The heart of the Eagle drive is the rear derailleur, which was developed on the basis of the 11-speed rear derailleur. Of course, the proven X-Horizon cage linkage is retained, thanks to which the rear derailleur and cage only move horizontally: This eliminates possible negative influences on the shifting behavior and creates space for large sprockets. The upper pulley has grown to 14 teeth, which are now narrow / wide like the chainring. In this way, the chain is guided more securely, which results in quieter operation overall.
SRAM Eagle rear derailleurs in comparison
The rear derailleurs of the various Eagle groups differ only in the materials used and thus in weight - the function should be equally good for all three variants.
Weight | Price (RRP) | |
---|---|---|
SRAM XX1 Eagle | 259g (reweighed) | 304€ |
SRAM X01 Eagle | 276g | 240€ |
SRAM GX Eagle | 290g | 110€ |
SRAM XX1 Eagle : The shifter
The secret star of every drive - whether on a mountain bike or a racing bike - is the gear lever. The commands go from this control center to the switching mechanism, which then implements them accordingly. In addition, it is the only point of direct contact with the gears for the rider – so ergonomics plays an important role. Technically, the Eagle Shifter largely corresponds to its 11-speed counterpart, with the exception of the additional twelfth gear. Five gears can be shifted up at once, down only one. However, the latter is not too tragic in practice thanks to the extremely short lever travel that is typical of SRAM. Speaking of ergonomics: The individual adjustment of the large shift lever, which can be rotated forwards or backwards by a few degrees, is very nice.
SRAM Eagle shifters in comparison
While the XX1 and X01 variants also differ in terms of materials and weight, the GX Eagle Shifter is a whole lot simpler overall. It looks a little less filigree and you have to do without the angle adjustment of the lever. By the way: Friends of the Gripshift twist grips will be pleased to know that these are still available for the Eagle series.
Weight | Price (RRP) | |
---|---|---|
SRAM XX1 Eagle | 123g (reweighed) | 170€ |
SRAM X01 Eagle | 126g | 145€ |
SRAM GX Eagle | 122g | 35€ |
SRAM XX1 Eagle : The Cassette
The great success of the 1-speed drives is inextricably linked to the wide range of cassettes. Visually, the large sprockets naturally take some getting used to, this was and still is the case for the 42-tooth representatives, but all the more so for the new 50-tooth sprockets, which have roughly the circumference of a 180mm brake disc. But of course, these new cassettes have one big disadvantage: the additional material puts a lot of pressure on the weight. There are different approaches to mastering this problem. Many manufacturers use aluminum instead of steel for the large sprockets - this is lighter, but also significantly less durable. At SRAM, they choose a different approach and try to keep the weight low through a complex construction and minimal use of materials. With success!
The SRAM XX1 Eagle cassette is almost a work of art, almost too beautiful to ride! The gold color has its part in this, as does the construction mentioned with the X-Dome in the middle, on which the respective sprockets are attached. Due to the very airy construction, the cassette is also hardly susceptible to dirt, as it usually just falls through inwards.
SRAM Eagle cassettes in comparison
It is one of the main points of criticism of the new Eagle drives: such complex cassettes as here have their price, and since they are wearing parts, frequent drivers in particular have to spend money regularly to maintain the very good shift quality. That's why it's definitely worth it for price-conscious riders to install one of the cheaper Eagle cassettes - provided you can live with the extra weight. Functionally, they do not differ.
Weight | Price (RRP) | |
---|---|---|
SRAM XX1 Eagle | 358g (reweighed) | 458€ |
SRAM X01 Eagle | 355g | 392€ |
SRAM GX Eagle | 450g | 200€ |
SRAM XX1 Eagle : crank and chainring
Let's come to the last "big" component of the drive, namely the crank. The SRAM XX1 Eagle crank is made of carbon - as befits a model from the top range - and is one of the lightest on the market at under 500g. SRAM recommends the lightweight for XC or trail use - for harder paces there is the new Descendant from subsidiary manufacturer Truvativ. The chainring is mounted using the now well-established Direct Mount mount.
A few words about the chain ring itself: This is equipped with the new X-Sync 2 tooth design, which is supposed to hold the chain just as securely as its predecessor, but is much quieter, even in difficult external conditions. The crank is available with 170 or 175mm crank arms, in GXP and BB30 and for Boost axles and in standard size.
SRAM Eagle cranks in comparison
Here, too, the differences between the two noble groups XX1 and X01 are marginal and ultimately only to be found in a few grams of weight. The situation is completely different with the GX Eagle crank: Not only is it considerably cheaper, but it is also made of aluminum instead of carbon and thus brings a lot of extra weight with it - although 650g is still a good value. All weight specifications are manufacturer specifications for a GXP crank with 175mm arm length and 32t chainring.
Weight | Price (RRP) | |
---|---|---|
SRAM XX1 Eagle | 493g | from €463 |
SRAM X01 Eagle | 520g | from €426 |
SRAM GX Eagle | 650g | from €125 |
SRAM XX1 Eagle : The chain
The chain in the drive is generally underestimated and often neglected. But it is precisely the chain that plays a decisive part in how cleanly, how quietly and how smoothly a drive works. For example, a lot has been invested in the XX1 chain to avoid any sharp edges. This makes it harder for them to get caught, even when the going is sandy or muddy. Hollow pins reduce weight and the gold-colored titanium nitride coating improves corrosion protection.
SRAM Eagle chains in comparison
Weight | Price (RRP) | |
---|---|---|
SRAM XX1 Eagle | 250g | 88€ |
SRAM X01 Eagle | 250g | 66€ |
SRAM GX Eagle | 270g | 29€ |
Website
In the next part of our build story, we will focus on the wheels and tires...
Mike says
The chains are but a few chunks! :-))))
SRAM Eagle chains in comparison
Weight Price (RRP)
SRAM XX1 Eagle 493g €88
SRAM X01 Eagle 520g €66
SRAM GX Eagle 650g €29
Michael Faiss says
Improves durability! 🙂
Thanks for the hint, corrected 😉