SRAM's new S-1000 Eagle Transmission brings wireless T-Type drivetrain benefits to more affordable MTBs

SRAM S-1000 Eagle Transmission derailleur on a cloudy sky background
Unfortunately S-1000 parts won't actually be floating down from the sky (Image credit: SRAM)

T-Type Transmission made its debut over a year ago appearing on SRAM's top tier XX, XX SL and XO drivetrains. This was followed up a few months later by Eagle Transmission at the more utilitarian GX level. The US mega-brand has now announced that the tech has trickled down to the lower-tier S-1000 version, but this latest T-Type level will only be available on production mountain bikes. Matching up with the new drivetrain system comes a new Stealth version of SRAM's wallet-friendly, mineral oil DB8 brakes too.

The SRAM S-1000 Transmission crankset

Color aside, the new S-1000 crankset looks fairly similar to the GX version and has removable bash guards (Image credit: SRAM)

Transmission amped

If you're unfamiliar with T-Type Transmission, it's a hangerless drivetrain system that bolts directly to rear dropouts and can only be fitted to bikes that run SRAM's UDH (Universal Derailleur Hanger). I've been riding with the GX version of Eagle Transmission for over a year now and while not quite 100 percent fool or bombproof, it's a far more robust gear system than the traditional. T-Type shifts perfectly under heavy loads (making it ideal for e-MTBs), set up is as straightforward as it gets, the mech has no adjustment screws, and being AXS, it's a wireless system powered by a battery housed on the mech.

There are four components that make up the S-1000 range:

  • S-1000 Eagle Crankset
  • S-1000 Eagle e-MTB Crankset
  • S-1000 Eagle Transmission Derailleur
  • XS-1270 Eagle Cassette

The SRAM XS-1270 Eagle Cassette on a white background

A replaceable cluster of the 10, 12, 14, 16 and 18t cogs is available for the 10-52t, 12-speed cassette (Image credit: SRAM)

If you've noticed that the S-1000 mech looks very similar to the GX version, that's because it uses the same architecture as its fancier stablemate. That means it gets the much more robust battery position protected on either side by the Full Mount attachment bracket – on XX, XX SL and XO, the battery sits in a more vulnerable position and has been known to get knocked off on occasion. The S-1000 gets an improved Drag Cage Spring Damper over the GX version, which is designed to boost chain tension.

Like all the other T-Type systems, the S-1000 mech is rebuildable with replacement parts (the skid plates, two-piece outer link and cage assembly) available separately. Transmission components are also compatible with each other, meaning you can mix up the various tiers.

Close up of the battery on an AXS MTB rear mech

The S-1000 mech uses the same battery position sandwiched between the Full Mount bracket as seen on the GX version here (Image credit: Rich Owen)

HG rather than XD

A key point of difference between S-1000 and the rest of its T-Type stablemates is that the new cassette uses a traditional HG splined driver rather than the SRAM-specific XD option. That means it can be used with wheels found on cheaper mountain bikes, as fancier wheelsets typically come with XD or Shimano Micro Spline drivers.

Aside from a black finish, the cranks look very much like the GX version and come with detachable bash guards. The crankarms are forged aluminum and run an 8-bolt chainring. The e-MTB version is made using the same process and comes in SRAM, Brose, Bosch, and ISIS-compatible versions.

There's no S-1000 series gear controller, but AXS rocker and T-Type Pod controllers can be used. S-1000 doesn't have a specific chain either, but as Transmission drivetrains can only run Flattop versions, expect to see GX chains being specced.

We've not had any word on S-1000 Transmission component weights from SRAM as yet, but we'll update this article as soon as we get them.

The SRAM S-1000 Transmission rear mech on white

The S-1000 rear mech uses the same design as the GX version (Image credit: SRAM)

How much are MTBs with S-1000 Transmission likely to cost?

While GX T-Type typically appears on MTBs starting at around $4,000 / £4,000, as you'd expect, S-1000 Eagle Transmission will bring the system to less costly mountain bikes. Unlike previous incarnations, the S-1000 system won't be available aftermarket and will only appear on production bikes.

As for the price point of bikes running S-1000. The only bike we're aware of currently listed with it is the Comp version of Specialized's recently revealed Stumpjumper 15. However, at $5,500 / £5,250 / €6,500, pricing on that is higher than most (the Expert version with GX Transmission is $6,500 / £6,000 / €7,500), as the bike includes a Ride Dynamics modded Fox "GENIE" shock and other fancy tech. We'd expect to see S-1000 Transmission on bikes starting at around $3,000 / £3,000 in future.

And, if you're wondering why SRAM has christened this new Transmission tier as S-1000 rather than NX or SX, the brand says it's because both of those systems are available aftermarket while S-series components are not.

Tech specs: SRAM S-1000 Eagle Transmission

  • Price: Not available aftermarket
  • Crank arm type: 8-bolt
  • Crank arm lengths: 150mm (e-MTB only), 155mm, 160mm, 165mm, 170mm, 175mm
  • Cassette: 12-speed, 10-52t
  • Cassette freehub type: HG
  • Bottom bracket type: SRAM DUB
Rich Owen
Editor, BikePerfect

Rich Owen is the editor of the Bikeperfect.com team. He's worked as a journalist and editor for over 24 years, with 12 years specializing in cycling media. Rich bought his first mountain bike (a rigid Scott Tampico) in 1995 and has been riding MTB for almost 30 years.

Current rides: Merida One-Forty 6000, Banshee Paradox, YT Jeffsy Core 3, Saracen Ariel 30 Pro

Height: 175cm

Weight: 69kg