Forty years is a long time in technology. The first cell phone was launched less than 40 years ago, and the distance between the first powered flight and the moon landing is only 66 years. 40 years ago, Shimano introduced the 105 Groupset, targeting "sport and urban riders. It featured clip-on downtube shifters, square-tapered cranks, and a bottom bracket with cage bearings. Now, following Dura-Ace and Ultegra's move to electronic shifting only, 105 has finally had its Bob Dylan moment and is going electric (which will not be without criticism).

While all of the top tiers of the major manufacturers' road bike groupset are now electric, Shimano had lagged behind SRAM in offering electronic shifting at three different levels With the release of the 105Di2 (nominally R7100), the leading Japanese component, caught up with their American rivals on this front without major shock.

So what is new? Is it the same old tunes with the same old amplifiers, or is it a new creative direction? Will fans of the old music who heard "Subterranean Homesick Blues" still get the nod? Have we over-extended Bob Dylan's metaphor?

If you want to shift with cables, Tiagra is probably your limit: The new 105 is only electronically controlled and uses the same semi-wireless setup as Ultegra and Dura-Ace. The shifter and rear derailleur are connected wirelessly, while the rear derailleur and front are directly connected by cable. This keeps the front end clean and free of wires, but does not completely eliminate the need to run cables through inaccessible parts of the frame.

Like the two upper group sets, the rear derailleur is the hub of the system, acting as a communication hub and as a charging port for the independent battery that powers both derailleurs.

Since the shifters have essentially been completely overhauled internally, Shimano has taken the opportunity to refine the ergonomics of the exterior. Gone is the upper texture, replaced for the most part by smooth rubber, similar to the previous generation hoods, but a series of grooves have been carved into the underside and small ridges have been applied to the outside of the upper, presumably to improve grip when rising from the saddle. In addition, the peak of the hood shape is raised to improve grip with the forearms horizontal (and presumably to make room for additional internal components, such as batteries and wireless transmitters).

The hood will also be able to communicate with most head units, but Shimano recently cut off integration with Hammerhead, so don't hold your breath on that one.

The new 105 groupset will feature a 12-speed cassette that is backwards compatible with existing Shimano 11sp freehub bodies. The two cassettes are 11-34 and 11-36, following Shimano's trend of pushing for simplified gear options, complemented by 50/34 and 52/36 chainsets like Ultegra's.

The new 105 groupset will be disc-only, which comes as something of a surprise given that the latest Ultegra and Dura-Ace still offer rim brakes. As with cable shifting, if you want a complete groupset, you will be limited to Tiagra unless they make a Majority-105 groupset hybrid with Ultegra/Dura-Ace shifters and rim brakes.

Retrografists and weight-weak riders may lament the complete absence of rim brakes, but disc brake fans will be pleased with the 105 Anchor update. Two new center-lock rotors with ice technology freezers (three layers and cooling fins) will improve pad life and keep rotor temperatures lower on long descents, which in turn will reduce rotor deformation and pad rub.

The pad rubbing that plagues almost all disc brake users is also addressed in the calipers, with a 10% wider pad gap.

Unlike Ultegra and Dura-Ace, 105 levers do not feature Servowave. Servowave is a system that increases the amount of brake opening and closing at the start of the lever stroke in order to increase pad clearance. Although unconfirmed at this stage, it may mean that the bite point of the 105 lever will be slightly closer to the bar than before.

It also incorporates an improved bleeding procedure that does not require the caliper to be removed from the frame.

Additionally, the introduction of 105-level (though officially non-series) carbon wheelsets (nominally C32 and C46 for climbing and general use, respectively) may go a bit under the radar. [Rim depths are 32mm or 46mm, with relatively modern 21mm-diameter internals and tubeless compatibility. Weighing in at 1,502 and 1,610 g. No word yet on hubs or spokes, but Shimano's standard cup-and-cone system is expected to be used.

"Are you sitting down?

The new Shimano 105 groupset is priced at £1,730, £1,000 more than the current version, marking a major change in the 105 lineage and a shift from "sport and urban" to "competition". Is Tiagra now the enthusiast's choice by default? Is Ultegra now a bit pointless?

Here is the price breakdown in the UK:

International pricing is a bit difficult to pin down, but in Europe it looks like the full groupset will be about €1,729.99 and the wheelset $1,049.99. More updates will follow.