First Look | The new SRAM S-1000 Transmission delivers wireless shifting at a cheaper price point

SRAM Transmission launched over a year ago, ruffling feathers with its unique direct-mount derailleur that waved goodbye to the traditional hanger. Built around a stronger interface that makes use of the UDH dropout standard, we’ve found Transmission to deliver incredibly positive shift performance with mostly rock-solid reliability. See our SRAM Transmission review for the lowdown.

Initially SRAM launched Transmission for its XX SL, XX and X0 groupsets, which made it a very expensive proposition. That was followed by the GX Eagle AXS Transmission a few months later that lowered the price of entry by quite a bit. While it has been a popular spec for 2024 mountain bikes and e-MTBs, it still isn’t exactly what you’d call ‘budget’.

And so with the aim of offering its wireless electronic technology to as many riders as possible, for SRAM has just unveiled its cheapest Transmission yet; S-1000.

sram s-1000 transmission axs eagle drivetrain
The SRAM S-1000 Transmission crankset is offered in specific versions for mountain bikes and e-MTBs.
2025 specialized stumpjumper comp 15
Expect to see the SRAM S-1000 Transmission on a lot of complete bikes for 2025. One of the first to launch is the new Specialized Stumpjumper 15 Comp.

An overview of the SRAM S-1000 Transmission

The SRAM S-1000 Transmission is a new entry-level groupset that’s designed for mountain bikes and e-MTBs. It’s a 1×12 drivetrain that employs wireless electronic shifting and a direct-mount rear derailleur, just like its pricier siblings.

The important thing to note with S-1000 is that it will primarily be for OEM supply. That means you’ll see it coming on complete bikes for 2025 and beyond, rather than being something that you’d purchase as an upgrade from your local bike shop. One of the first bikes it’ll be coming on is the just-released Specialized Stumpjumper 15 Comp.

It’s also not a complete groupset. There will be a S-1000 derailleur, cassette and crankset, but there is no specific chain or Pod controller. Given S-1000 is fully compatible with SRAM’s other T-Type Transmission components, you’ll likely to see it mixed and matched on complete bikes. For example, a brand might spec a S-1000 crankset and cassette, then pair it with a GX derailleur and chain.

sram s-1000 transmission axs eagle drivetrain
The SRAM S-1000 Transmission derailleur is almost identical to the GX version.

What are the differences between SRAM S-1000 & GX Transmission?

The SRAM S-1000 Transmission offers a lot of structural similarities with GX. In fact, the derailleur is almost identical save for its all-black finish and the use of a new cheaper drag spring cage damper. It’s also fully rebuildable and upgradeable, so you can replace the skid plates, two-piece outer link and cage assembly should they sustain any damage.

There will be two S-1000 cranksets available, one for e-MTBs and one for mountain bikes. The former is offered in SRAM, Brose, Bosch and ISIS variants, while the latter utilises the same DUB bottom bracket standard as the XX, X0 and GX cranksets. It also utilises the 8-bolt chainring interface,  and it’s compatible with the two-piece bashguards that bolt directly into the chainring. SRAM will be producing the forged alloy crank arms in lengths from 155-175mm.

sram s-1000 transmission axs eagle drivetrain cassette
Offering a 10-52T spread, the SRAM S-1000 Transmission cassette is designed to slide onto a HG freehub body.

The SRAM S-1000 Transmission cassette

Really the biggest difference with the SRAM S-1000 Transmission is the cassette.

Adorned with the XS-1270 label, the cassette employs the same 10-52T ratio and 520% gear range as its pricier siblings. However, unlike the more expensive GX, X0 and XX cassettes that use the XD interface, the S-1000 cassette is designed to fit rear hubs with a HG freehub body. This is an important distinction because cheaper OEM wheelsets often feature a HG freehub. Previously SRAM had only offered its NX Eagle 11-50T cassette to suit that interface, and of course the NX cassette isn’t compatible with T-Type Transmissions.

In terms of construction, the new S-1000 cassette features nickel chrome-plated steel cogs and the distinctive X-Sync tooth profile. The smallest four cogs (10-16T) are welded together to form a single cluster (rather than being machined from a single billet of steel, like a GX cassette). The standalone 18T cog then slides onto the freehub, while the rest of the cassette uses individual cogs that are pinned together.

The new S-1000 cassette is particularly notable for squeezing in a tiny 10T cog, which is difficult to achieve with a HG freehub. It’s possible in this case due to the first four cogs forming a single piece, and because the T-Type Transmission is specifically designed around a 55mm chainline. This sees the cassette pushed further outboard from the centre of the hub, providing more room for the 10T cog to hang off the end of the freehub body. Clever!

sram s-1000 transmission axs eagle drivetrain
We expect bike brands will be mixing and matching the new SRAM S-1000 Transmission with other T-Type components.

Will it be available to purchase?

As mentioned above, the SRAM S-1000 Transmission is primarily made for OEM spec on complete bikes. That means you won’t be able to buy the individual components separately, or at least not to begin with anyway.

However, because the S-1000 derailleur uses a very similar construction to the GX version, it is possible to purchase spare parts including the skid plates and cage assembly. And while the S-1000 cassette won’t be available as a complete unit, SRAM will be offering the 10-18T cogs as a replacement part (price TBC). That’s a good move, especially for e-Bikers that tend to wear out the smallest cogs first.

Indeed we’re stoked to see SRAM continue to expand on its Transmission range, and we expect you’ll be seeing a lot of S-1000 components spec’d on 2025 mountain bikes and e-MTBs.

2024 trek fuel exe 8 gx axs transmission emtb electric
There are a choice of different AXS controllers that are compatible with the SRAM S-1000 Transmission.

There are updated SRAM DB8 brakes too

Alongside the new SRAM S-1000 Transmission, the DB8 brakes have been updated as well.

The DB8 is SRAM’s entry-level hydraulic disc brake that runs on mineral oil and features a chunky four-piston calliper. It comes fitted with organic brake pads as standard, though because it uses exactly the same pad shape as the Codes, it’s possible to fit metallic pads if you’re after longer wear life and consistency in wet conditions. Utilising the thicker HS2 brake rotors is also a great upgrade for boosting power and durability.

For 2025, SRAM has updated the DB8 lever design to give it a similar Stealth profile as the latest Code, Level and Maven brakes. This sees they hose exiting at a near-parallel path in front of the handlebar, which is mostly an aesthetic choice that works particularly well with bikes that employ headset routing.

The DB8 lever otherwise carries over the excellent MatchMaker X hinged clamp, and the ambidextrous design means the brakes can be easily flipped from left to right. You can also dial in the lever reach to your preference using the tooled adjuster.

sram db8 brake
The SRAM DB8 brakes get an update for 2025 too.

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