Trek has gone back to basics with the new fifth-generation Domane, enabling it to shave a claimed 305g from the frame weight. The weight saving comes from a simplified design that ditches the IsoSpeed system that had been a feature of the Domane since its launch in 2012.Instead, Trek claims its carbon layup and a new, round seatpost thats designed to flex vertically provide vibrational energy absorption thats within 5% of the previous-generation bike. Ride comfort is helped by the increased tyre clearance, which is now 40mm, in place of the previous-generation Domanes 38mm.According to Trek: The simplified Domane goes back to the roots of endurance riding as the ideal lightweight, all-road carbon bike. 2012 vs 2027 Trek Domane: how Treks carbon endurance bike has gained tyre clearance and lost IsoSpeedLower weight, lower prices So long IsoSpeed, thanks for the ride and so long in-frame storage, too. When Trek asked its customers what they wanted to change in a Domane update, it says they asked for a lighter bike, with lower-priced options and a more upright ride position.However, they were ambivalent about IsoSpeed. Trek points out it was a solution for its Paris-Roubaix winning pro bikes from a decade-plus ago, when a wide tyre meant 25mm. With 40mm tyres now an option, IsoSpeed is essentially excess weight.Trek says the 305g weight loss for the new bike comes from the 835g frame and 367g fork weight, versus around 1,055g for the fourth-generation frame and 430g for the fork. Trek says the Domane's carbon layup, round seatpost and 40mm tyre clearance offer vibration absorption on a par with IsoSpeed. Despite speccing 35mm instead of 32mm tyres on the new Domane, Trek claims the bike is as fast as its predecessor. It says, aerodynamically, 35mm tyres are 0.9 watts slower at 20mph, but they reduce rolling resistance by 1.5 watts. You can fit Treks aero bottles, introduced with the Gen 8 Madone, if you want to shed a few extra watts of drag.Trek will offer the new Domane in its 900 Series OCLV carbon in SLR builds and 500 Series carbon in SL bikes, both also used for the Madone. The frame sports a T47 bottom bracket and SRAM UDH, while the front derailleur mount is removable for 1x drivetrains. Trek's new bar has a 20mm rise for a more relaxed ride position. The frame geometry is carried over from the fourth-generation bike, but the new bikes handlebar has a slight rise, raising it by 20mm for a more upright endurance ride position without the need for excess spacers.Theres a backsweep to the bar tops too, as well as a 40mm flare to the drops. The Pro version of the cockpit also has padding on the tops for added comfort. The Domane can be fitted with a top-tube bag and a frame bag for carrying capacity, but there's no in-frame storage. While many endurance bikes now include in-frame storage and the 2020 Domane was one of the first to add this feature, somewhat surprisingly Trek has gone the other way with the new Domane.It has added more bag mounts though, with top-tube and frame-bag mounts in addition to mudguard mounting points. Nevertheless, were fans of in-frame storage, with Warren declaring himself done with saddle packs. He may have to think again.Trek Domane Gen 5 specs and prices The lightest SLR 9 AXS 1x build has a 6.63kg claimed weight. Trek will sell the new Domane in six sizes. In line with the trend for shorter crank lengths, it specs 160mm cranks on XS and S frames, 165mm on M and ML and 170mm on L and XL bikes.It claims a 6.63kg weight for the flagship SLR 9 AXS 1x bike, equipped with SRAM Red XPLR AXS, Bontrager Aeolus RSL 37 wheels, Pirelli P Zero Race RS 28mm tyres and a Trek Aero RSL cockpit.Domane SLR 9 AXS 1x Frameset: 900 Series OCLV carbon Groupset: SRAM Red XPLR AXS Wheelset: Bontrager Aeolus RSL 37 Tyres: Pirelli P Zero Race RS, 28mm Claimed weight: 6.63kg Price: 9,000 / $11,499 / 10,499Domane SLR 9 AXS Frameset: 900 Series OCLV carbon Groupset: SRAM Red AXS Wheelset: Bontrager Aeolus RSL 51 Tyres: Bontrager Kwaremont RSL, 35mm Claimed weight: 7.29kg Price: 9,000 / $11,499 / 10,499Domane SLR 9 Frameset: 900 Series OCLV carbon Groupset: Shimano Dura-Ace Wheelset: Bontrager Aeolus RSL 51 Tyres: Bontrager Kwaremont RSL, 35mm Claimed weight: 7.34kg Price: 8,500 / $10,999 / 9,999Domane SLR 7 AXS Frameset: 900 Series OCLV carbon Groupset: SRAM Force AXS Wheelset: Bontrager Aeolus Pro 51 Tyres: Bontrager Kwaremont RSL, 35mm Claimed weight: 7.73kg Price: 6,700 / $8,499 / 7,499Domane SLR 7 Frameset: 900 Series OCLV carbon Groupset: Shimano Ultegra Wheelset: Bontrager Aeolus Pro 51 Tyres: Bontrager Kwaremont RSL, 35mm Claimed weight: 7.66kg Price: 6,300 / $7,999 / 6,999Domane SL 7 AXS 1x Frameset: 900 Series OCLV carbon Groupset: SRAM Force XPLR AXS Wheelset: Bontrager Aeolus Pro 51 Tyres: Bontrager Kwaremont Pro, 35mm Claimed weight: 8.14kg Price: 4,750 / $6,500 / 5,000Domane SL 6 AXS Frameset: 500 Series OCLV carbon Groupset: SRAM Rival AXS Wheelset: Bontrager Aeolus Elite 50 Tyres: Bontrager Kwaremont Pro, 35mm Claimed weight: 8.64kg Price: 3,750 / $4,200 / 4,000Domane SL 5 Frameset: 500 Series OCLV carbon Groupset: Shimano 105 Wheelset: Bontrager Paradigm 23 rims on Formula hubs Tyres: Bontrager Kwaremont Pro, 35mm Claimed weight: 8.84kg Price: 2,500 / $2,700 / 2,500Domane SL 4 Frameset: 500 Series OCLV carbon Groupset: Shimano Tiagra Wheelset: Bontrager Paradigm 23 rims on Formula hubs Tyres: Bontrager Kwaremont Comp, 35mm Claimed weight: 9.10kg Price: N/A / $2,400 / N/ATheres also a special Project One edition of the Domane SLR 9 AXS, priced at 11,250 / $14,999 / 12,999, with only 124 bikes available worldwide.