Sram's funeral speech caused emotions to boil over. The video is an obituary for the front derailleur. The part on the bike that Sram wants to do without on all MTB groupsets in the future. According to the component giant, a new front derailleur for off-road use will never be developed again.
Simply simple since 2012
Sram laid the foundation for the simple philosophy back in 2012 with the XX1 shifting group. A chainring at the front in combination with an 11-speed cassette on the rear wheel. By dispensing with the front derailleur and shift lever, Sram saved weight and simplified shifting. In addition, the new narrow-wide tooth profile on the chainring ensured significantly better chain guidance. While specialists and racers found the 1x11 drivetrain to be a very good alternative to double or triple systems, generalists criticised the limited range of gears.
More bandwidth is the key
The new 12-speed cassette addresses precisely this point of criticism and extends the range by 80 per cent. With 10 to 50 teeth, the two new Sram Eagle drivetrains (XX1-Eagle and X01-Eagle) create a range of 500 per cent, which corresponds to a 2x11 Shimano drivetrain with a 26/36 crank and 11-40 cassette. Anyone who has already ridden a 1x11 drivetrain will clearly notice the increased range. Even with a four-tooth larger chainring, you still have an easier climbing gear and can also push harder downhill. For example, if you used to ride a 32-tooth chainring with the Sram 1x11 groupset, you can now ride a 36-tooth chainring with 1x12 with the same or slightly lighter mountain gear ratio.
A calculation example for the climbing gait:
Sram 1x11: 32:42 = 0.762
Sram 1x12: 36:50 = 0.72
With a cadence of 60 to 90 revolutions per minute, the new Eagle drivetrain (36 teeth and 27.5 inches) allows a speed range of 5.8 to 43.5 km/h. With the previous 11-speed cassette, the speed range with a 32 chainring is significantly narrower at 6.2 to 38.7 km/h under the same conditions.
Lighter than 2-fold
Sram continues to promise a weight saving of 300 grams compared to a 2x groupset with the new Eagle groupsets. Compared to the previous 11-speed drivetrain, the groupset is only slightly heavier. The new, significantly larger cassette (355 grams) is the main factor driving up the weight. With the help of the new carbon cranks (specially developed for this application), the disadvantage is almost neutralised. Sram estimates 50 grams more than the previous XX1 and 80 grams more than the X01 counterpart. The complete groupsets should therefore weigh 1596 grams (XX1-Eagle) and 1645 grams (X01-Eagle).
Technology in detail
The new Eagle is based on a 12-speed cassette whose smallest eleven sprockets are milled from a single piece of steel. The gradation is also the same as the previous 11-speed cassette. In addition, there is a 50 mm sprocket made of aluminium. But another sprocket is only a small part of the new groupset. Almost all details have been fundamentally revised. In order to be able to use the existing 11-speed XD freehub body, the sprockets have been moved slightly closer together and the chain has been made marginally narrower (2.5/10 mm). Thanks to a new riveting process, the chain pins no longer protrude beyond the outer plates, which also saves space. The inner plates have been rounded to minimise wear. The new profile of the chainring teeth is also striking. Sram continues to rely on thick/thin, but has optimised the tooth shape so that the chain moves more quietly and yet with optimum guidance over the teeth. Various tests in the Sram laboratory have shown up to eight times longer durability. In order to cope with the larger capacity of the derailleur, the lower pulley of the Eagle rear derailleur was enlarged from 12 to 14 teeth and the cage was minimally lengthened. Thanks to a plain bearing, the problem of the rear derailleur mounting bolt coming loose should also be a thing of the past. Both new carbon cranks have also been put on a diet and optimised according to their intended use.
Minimally more expensive than 11-speed
Despite a wealth of technical improvements, the Eagle groupsets are only around five per cent more expensive than the previous 11-speed top groupsets. Sram is asking 1524 and 1306 euros respectively for the complete groupsets.
"Eagle lasts eight times longer!"
BIKE: Twelve gears mean a narrower chain and greater skew. Does this have an effect on durability?
Frank Schmidt: The chain has only become marginally narrower and is manufactured completely differently. There is no difference to Elffach in terms of tensile strength. Thanks to the new tooth profile and the more precise coordination of the components, we were even able to determine an eight times longer service life in the laboratory than with the predecessor parts.
Are there any restrictions, or can the new Eagle groupsets be retrofitted to all Eagle-compatible interfaces?
The cassette fits our previous XD freehub bodies, and nothing has changed in the chainline either. The clearance to the chainstay can be the limiting factor on some bikes if you want to ride a larger chainring.
What is the increase in bandwidth comparable to? And don't you have to put up with bigger gear jumps?
Our new system offers the same range as an existing 2x11 system from the competition, but can be fine-tuned via the chainring sizes. In the range from 10 to 42, the gear steps are identical to our previous cassette.
Will the new groups be more expensive and will 12x also be introduced for the lower groups?
The prices for the new groups will only be around five per cent higher than the previous groups. Cheaper groups are conceivable.
