SRAM’s Transmission drivetrains have been the hot topic since their release in March last year as they ushered enhanced durability, smooth shifting under load and consistent gear changes to mountain bike drivetrains. Now, SRAM has unveiled Red XPLR AXS, a 13-speed, 1x-only gravel groupset that borrows the very same tech but simmers it down into a gravel-specific package – and means brands don’t have to kit their UDH (Universal Derailleur Hanger) equipped gravel bikes with the MTB-focussed drivetrains anymore.
Single chainring 1x drivetrains, as well as big cassettes, have already found a foothold in the world of gravel with the single-ring being the preferred setup for most gravel riders. SRAM is fully embracing that, and as such its newest gravel groupset only comes in a 1x guise. Whereas that’s maybe not to everyone’s liking, in SRAM’s defence they have added an extra cog to the back – something only a few brands have done before.
13-speed gravel drivetrains have been long limited to Campagnolo and Rotor – though neither offers electronic shifting. To ruffle up things and how we’ve come to think about gravel drivetrains, SRAM has expanded on the technologies introduced with its T-Type drivetrains in a bid to create the ‘ultimate’ gravel drivetrain.
The most significant part of the new SRAM Red XLPR drivetrain is the introduction of a direct-mount derailleur. It attaches to any UDH-equipped bike, and SRAM says that setup is simpler as the mech comes with no adjustment screws to worry about. The brand also states that the new mech provides even better chain management than before thanks to the MTB-inspired clutch it’s built with, and as it comes with the Magic Pulley Wheel found on the XX SL, it also boasts extra reliability as it should keep spinning even when obstructed by a stick or lots of dirt.
The derailleur aside, the new groupset obviously also introduces a new cassette with an extra cog: the whopping 13-speed Red XPLR XG-1391 cassette allows the drivetrain to offer a 460 per cent range over the span of the 10-46t cogs. The whole idea behind the 13-speed setup, compared to 11 and 12-speed groups, is that Red XPLR provides closer spacing between shifts. The new cassette is only compatible with the Red XPLR mech and vice-versa, though. SRAM says the cassette weighs 288g and it’ll work with all of SRAM’s road Flattop chains.
New things don’t end there, because the crankset is all new too and SRAM claims that the cranks are the brand’s lightest but stiffest yet. According to the brand, this crank boosts tyre clearance and uses hollow carbon arms. The crankset is available from a short 160mm length to the longest 175mm option. Non-aero direct mount chainrings stretching from 38t to 46t in size can be swapped using only one tool. Of course, it’s also compatible with SRAM’s DUB bottom bracket standard.
No top-end, high-performance SRAM groupset would be complete without power meter options and the Red XPLR AXS is no exception. The dual-sided, spider-based power meter promises +/-1.5 per cent accuracy and reliability in all conditions. SRAM has also built it to meet IPX7 waterproofing standards, so it should remain waterproof in up to a meter of water for 30 minutes. This power meter is available in the same crank lengths as the regular crankset and benefits from the hollow carbon fibre arms as well. Both the power meter spider and Thread Mount Chainring can be bought separately.
As for prices, SRAM Red XPLR AXS AM will set you back £3,980 with the power meter or £3,530 without.
Our Aaron’s already spent a lot of time on SRAM’s latest gravel groupset, so for actual weights and his verdict, check out his SRAM Red XPLR AXS groupset review.