With 13th sprocket, without derailleur hanger: The new SRAM Red XPLR in a ride test

It was no longer a secret that the component specialist from Chicago was planning a new top-of-the-range groupset for off-road riding. The first pictures of the Red XPLR AXS circulated around the Unbound, the unofficial world championship for gravel bikers. Two months later, SRAM has now confirmed the new drivetrain, which is said to be nothing less than the US manufacturer's "most advanced gravel groupset". Thanks to a fusion of road and MTB drivetrains.

Mixture of road and MTB drivetrain

From the almost eponymous and also overhauled top gearstick Red the improved shifting performance and impressive braking power are carried over, while the robust rear derailleur is adapted from the Eagle Transmission. In addition, the cassette is based on 13 sprockets for the first time. Until now, this was a unique selling point of Campagnolos Ekar.

Compared to the previous twelve-speed gearbox, a sprocket with 12 teeth is new, and the largest sprocket now has 46 teeth instead of 44. This increases the gear range by 20 per cent and is slightly larger than that of double road groupsets. Despite the mono chainring, which SRAM has been committed to since the introduction of the XPLR three years ago. Shimano currently only relies on a Dual version of the electronic twelve-fold GRXCampagnolo, on the other hand, only offers its two 1X13 groupsets as mechanical versions.

SRAM Red XPLR: The most important facts

• Gears: 1x13
• Chainrings: 38, 40, 42, 44, 46 teeth
• Cassette: 10-46 teeth
• Price: 3960 Euro (without power meter), 4465 Euro (with power meter)
• Total weight: 2471 grams (weighed weight)

The Red XPLR has a total of five chainrings to choose from, which can be unscrewed using a special tool in the event of wear. Unlike the Red AXS, the optional power meter (€560) does not have to be replaced, but the chainrings (€170) are still very expensive. The XPLR takes the carbon crank arms from the road group, with a new short 160 millimetre version.

Full mount instead of derailleur hanger

In addition to the new 13-speed cassette, in which the three largest sprockets are made of aluminium and are noise-damped with foam, the Full-mount rear derailleur the highlight of the new gravel groupset. As with the new MTB drivetrains, this no longer hangs on a derailleur hanger, but is attached directly to the thru axle with two aluminium brackets.

The design offers two advantages: On the one hand, the suspension is more robust; a so-called "magic wheel" on the lower derailleur pulley is even supposed to keep the chain moving if a small branch gets caught in it. On the other hand, the rear derailleur can be adjusted more easily and more precisely; there is no longer any need to pay attention to end stops or the correct distance to the sprocket set. Once set, the shifting performance should not change, SRAM promises. With a little practice, the adjustment should take around ten minutes; the in-house app guides you through the process.

If something does break in the event of a fall, individual parts are available separately. The rear derailleur is only compatible with frames with a UDH interface. SRAM introduced the standard in 2019 and it is now gaining ground on gravel bikes in particular, with more and more road bikes now also using it.

Red XPLR AXS in the first driving test

In an initial practical test around SRAM's development site in Schweinfurt, the Red XPLR was able to fully convince. The gears change quickly and precisely under full load, but it's not quite as quiet as the road drivetrain. We hardly needed the lowest uphill gear (40-46), but we would have liked a slightly higher gear ratio on descents. However, this can easily be changed with a larger chainring. The braking performance is simply impressive and comes into its own even better than on asphalt: the ergonomically shaped brake levers are easy to reach on bumpy roads, and a light pull with just one finger is all it takes for the discs to apply a powerful grip.

Technology (still) at a high price

The XPLR, which weighs 2471 grams (weighed), is initially only available in the expensive top version. Even without the power meter, it costs 3960 euros. The individual parts are also extremely expensive, with the cassette alone costing 657 euros. However, it can be assumed that the Americans will soon pass the technology on downwards. According to TOUR information, the new XPLR versions of the Force and Rival will follow next year. SRAM did not want to comment on this when asked.

New wheels and tyres for off-road use

In addition to the new Gravel gear Red XPLR SRAM and its subsidiary Zipp present further exclusive components for off-road racing. The highlight is the new 303 XPLR carbon wheels. Their unique selling point is a hookless rim in XXL format: Zipp promises "the fastest gravel wheel ever" thanks to the combination of a huge rim width (32 millimetres) and large rim height (54 millimetres). Two versions are available: the lighter SW version (1800 euros) weighed in at 1607 grams on the TOUR scales, while the S version (1200 euros) is said to be around 150 grams heavier.

Extremely wide carbon rims

The extreme rim profile is said to improve aero performance by five watts at average racing speeds. At higher speeds, which are rarely reached off-road, the wheel benefits exponentially and is said to be up to ten watts faster over large angles of attack. The prerequisite for this is a 40 millimetre wide tyre, which Zipp - unsurprisingly - has also added to its range. In cooperation with Goodyear, the XPLR Slick (455 grams, 90 euros) was created, which continues the rim shape almost seamlessly and is primarily suitable for smooth gravel paths due to its smooth tread.

We tried out the slightly more profiled and wider XPLR Inter (525 grams, 90 euros). The 45-millimetre rubber rolls very well, even on tarmac. However, the Goodyear does not offer much lateral support when changing direction quickly on loose surfaces. As the wheels with reinforced rim allow low tyre pressure, the suspension comfort is very good. As a rule of thumb, Zipp recommends 0.5 bar less tyre pressure than comparable station wagons. In addition to Zipp's own tyres, around 25 tyre models will be compatible with the new hookless rims at market launch. An up-to-date list can be found on the manufacturer's website and in the in-house app.