Details of the new-for-2011 Shimano 105 groupset, coded 5700, have been made public prior to an advised availability date of May 2010 for the double and compact chainset versions and June 2010 for the triple.
As expected, the latest version of 105 is effectively an economy version of the current Dura-Ace and Ultegra 10-speed groups, closely following their aesthetic treatment while saving on cost by eschewing the use of titanium and carbon-fibre composites. Two finishes – Lodestar Black and Sterling Silver – will be on offer.
As ever, the crankset is built around Shimano’s Hollowtech II technology and features hollow cranks, an axle integral with the right-hand crank and outboard bottom bracket bearings. The appearance of the cranks and chainrings is close to that of its siblings but 105 does not have the Hollowglide tubular outer chainring. Tooth options will be 53/39 and 52/39 for the double, 50/34 for the compact and 50/39/30 for the triple.
The dual control levers have bee redesigned to route both brake and gear cables underneath the handlebar tape. Shaped along the lines of Ultegra 6700, they have reach-adjustable levers shaped to work with smaller hands and a variety of bar bends.
Two versions of the rear derailleur mechanism will be on offer, the long cage example required to work with the triple chainset while the short cage mech will work with the compact chainset and accommodate a rear sprocket with up to 28 teeth. The two front derailleurs – double and triple – have a wider inner link for increased rigidity and should offer improved shifting thanks to a reshaped chain guide profile.
A new block compound formulated to offer improved braking performance, especially in wet conditions, is the major upgrade feature of the new 105 brake calipers, which are reshaped in line with the rest of the group. The brake shoes feature adjustable toe-in mountings.
A “directional” chain with specially-shaped links and a 105 version of the latest Hyperglide cassette, the latter available in 11-28, 11-25, 12-25 and 12-27 tooth counts, complete the transmission. Hubs and pedals in matching colour finishes complete the groupset.
