2023 Trek

Rail 9.9 CXR Gen 4

A few years have gone by since the last Rail review. Lots has changed since then. Pete reviews the Trek Rail 9.9 X0 AXS T-Type Gen 4.

Read Review

Trek’s Rail is claimed to be enduro-descent ready and uses Bosch’s powerful Performance Line CX motor

Read Review

The last time we rode the Trek Rail we awarded it our 2021 E-Bike of the Year crown in the shop bought category. Since then we haven’t had another chance to ride one, mainly because they’ve been flying off the shop floor. Meanwhile, Trek hasn’t rested on its laurels – the front triangle has been lengthened and the extra space used to stuff in Bosch’s biggest 750Wh battery on all but the smallest frame size. So how does it perform and is it one of the best electric mountain bikes on offer? Need to know: Mino link on the seatstay/rocker interface gives high and low geometry settings – useful if you want to run a 27.5in rear wheel Knock Block steering limiter uses interlocking stem and headset spacers, while steerer tube gets oversize 1.8in taper Top tube System controller and wireless remote are available to buy aftermarket, but they should come as standard M, L, and XL frames get 750Wh battery, while S gets a 625Wh This updated Rail is called the Gen 4, but you can still buy the old Gen 3 model. It gets the smaller 625Wh battery, non-Smart System-compatible electronics and a shorter reach. Although buying the Gen 4 seems like a no-brainer, the new large frame is a really big bike, with a 490mm reach and a yawning 35mm gap to the medium. So some riders may achieve a better fit on the old Gen 3. It’s disappointing that Trek hasn’t fitted the latest Bosch System Controller (as found on the Mondraker) to the top tube. Instead you get a measly blanking plate. To enjoy the improved integration and reduced clutter you’ll have to fork out an extra £1,600 for the next model up, which seems pretty stingy. Suspension Trek claims the Rail delivers 150mm travel, but we only measured 140mm (3mm less than the last Rail we tested). However, we didn’t notice this shortcoming on the trail, mostly because the long wheelbase of the Rail gives it excellent stability at high speeds on rough ground. Where we found it wanting was in terms of grip and sensitivity. It struggled to trace smaller bumps, so not only did it lack some comfort on long rides, but it needed more effort to hold a line on off-cambers, through slow turns, and in the wet. Having said that, there’s plenty of support, so as long as we had the energy, we could ride the Rail like a runaway train. Our bike came with a RockShox Zeb in place of the advertised Domain RC. With 38mm stanchions it perfectly matches the hench proportions of the Rail frame, but it wasn’t the smoothest or most supple fork on test. In that respect there was a symbiosis between the Trek’s front and rear suspension, even if it wasn’t quite the fairytale relationship we’d hoped for. Components Trek proffers two brake specs on the Rail 9.7 – Shimano Deore or SRAM Code R, both in four-piston guise. Given the choice, we’d take the Shimano …Continue reading »

Read Review