Shimano has released details of its all new 105 groupset. Revamped for 2014/15, the drivetrain is now 11-speed, with all components gaining trickle down technology from the company’s existing Ultegra and Dura-Ace groups.
Importantly, the new 105 can also be combined with Shimano’s recently announced, second generation hydraulic disc brake for road bikes – in a system that debuts mechanical shifting with hydraulic braking for the company.
There are several chainset options for the new 105 including the FC-5800, a new four-arm Hollowtech II design similar to that of current Ultegra and Dura-Ace. it’s stiffer and lighter than the five-arm design it replaces, and Shimano has reinforced construction around the chainring area to further improve the stiffness to weight ratio. The chainset uses the same bolt circle diameter for compact and traditional double chainsets, which means one crankarm fits all chainring sizes.
Gearing options are as follows: 50-34t, 52-36t or 53-39t, and both black and silver colour options will be available. The crankset can be used with Shimano’s SM-BBR60 bottom bracket or, should your frame require it, the SM-BB72-41B press-fit bottom bracket.
Shimano will also continue to produce five-arm Hollowtech II chainsets in all popular gear combinations for the 105 group. Crank length options will be 165mm, 170mm, 172.5mm and 175mm.
ST-5800 dual control shift levers
105 now gains the light yet positive shift action found in Dura-Ace and Ultegra levers; there’s also a new compact shape that’s borrowed from the the levers of Shimano’s more expensive groups. The lever can adjusted to accommodate different hand sizes via a 10mm screw-type reach adjustment. Polymer coated cables are now standard.