Evolution - the natural selection of inherited variations that increase ability to compete, survive, and reproduce. So far, so spot-on. But when we force the ugly word of “constant” before this clearly superior noun, the disconnect begins. Our never-ending pursuit of the next new thing, missing the crux point, evolution cares little for haste.So, to the BMW Boxer engine. The new 1300 is a wonder, the shift-cam 1250 a globe-conquering legend, but with their adoption of water-cooling, both saw fit to make redundant the inherent cooling benefits of their cylinders sticking out sideways in the first place. Granted, air-cooling had to tap-out when asked to cut through the heat our desired performance produces, but the air/oil-cooled evolution of the Boxer that entered the game in the late 90’s? To many, that power-unit is peak Boxer. And that, give-or-take a few (thousand) tweaks and Euro-induced platitudes, is the engine with which BMW have kept faith for the next evolutionary step of their iconic RnineT. As you were, as it were.A Shed-regular and proud owner of a perfectly original RnineT, tells the story of when he went to test ride the new machine in 2014. The salesman told him it was merely a styling exercise - designed to use up the last of the old engines. It would be made to the limited number of units remaining and discontinued, his unenthusiastic pitch. Ten-years on, it is fair to assume the success of this “parts-bin special” means they would have had to cobble-together a few more motors. It is also safe to assume that said salesman would have felt certain the latest water-cooled lump would finally retire the ancient motor for the RnineT’s successor... Thankfully BMW HQ recognised that in a machine pitched as the R12, R12nineT and RnineT before them, it is the last thing that needed changing.It is the beating heart of these motorcycles. Torque and power are abundant, but it is the character, the visceral shake and almost agricultural feel that make it so apt for this deployment. If you are going to tag a machine with the moniker of Heritage, it has to stir emotion. Big, fat tick.So what is new? A whole model for a start. The RnineT was no stranger to derivations; the Racer, Scrambler, Pure, Urban GS etc. But give or take a few parts, they were largely the same base machine. But with the R12 now sitting alongside the R12nineT, BMW have added a whole new genre to the pot. On the day this particular R12 was delivered to the Shed for me to test, Rory and Stu from Pier City Cycles were in town. These gents have forgotten more about customising BMW’s heritage line-up than most will ever know, and the first thing they celebrated of the new models, was the revised bolt-on subframe. Well, it was actually the return of that engine, but once we were past that, it was onto the subframe. (Check out the video we made together on the R12 HERE.)The original RnineT frame was one piece, nose to tail, but with the new bolt-on arrangement, BMW (and the guys at Pier City) have far greater flexibility in the geometry of subsequent models/builds. With this stand alone subframe and tank, the R12 cuts a very different silhouette to the roadster styled R12nineT. After the considerable proposition that was the R18 cruiser, the R12 offers similar style, in a far more compact, usable package. It also restricts peak power to sub 100 horses, enabling A2 compliance. As the most obviously altered of the two new machines, it was the one I was most eager to try.I won’t continue to lavish broad praise on the engine (this far into the article you should be aware how strongly I feel about it) instead, let’s get into the details. There are two riding modes, named for reasons no sane person can fathom, Rock & Roll. Once you have recovered from the cringiness of their naming convention, you discover they offer two totally different personalities. At tickover, “Roll” provides a steady, calming purr. Flick to “Rock” and the purr is replaced with an off-beat gallop that begs you to get going. And when you do, the chassis is more than obliging.Perhaps via nominative determinism, manufacturers creating machines to occupy the genre of “Cruiser” can often be less focused on the handling capabilities of the finished article. Not so with the R12. Fat upside-down Marzocchi forks, mighty Brembo brakes front and rear coupled with that inherent low-down, boxer weight distribution result in a machine that thrives in the twisties. Aided by the relatively low seat height and glorious quick-shifter, the R12 is a hugely confidence inspiring set-up, prompting much peg scraping shenanigans...As a lofty unit, my body rarely enjoys cruiser geometry and locked-in seating positions, but once on the move, I feel surprisingly at home on the R12. At a standstill, figuring a location for my (admittedly) disproportionately long-lallies, proved somewhat harder. With the cylinders reminding my shins not to venture forward, I instead find myself straddling the low centre of the bike like a saddle-sore cowboy on a Shetland pony. Whilst I might look a little odd at lights, it at least gives an opportunity to savour the sumptuous detailing of the bike. With the optional "Option 719" pack, this model is covered in highlights.The slender digital dash, shadow “billet pack”, cleverly shaped bar-end mirrors and 90’s BMX aping gold handlebar... the quality of the R12 componentry is second to none. As always, spending too long in the BMW configurator can dramatically increase the price of your desired steed, but at base price, the R12 is somewhat of a steal. At two grand less than the more powerful R12nineT, it becomes a hugely tempting proposition in it’s class.I am yet to ride the R12nineT, but a huge fondness for the previous model coupled with the raft of updates experienced in the R12, leave me in no doubt that it will be a worthy and staggeringly capable descendent of the original RnineT. But in the evolutionary divergent R12, BMW have landed on a second, equally compelling machine in its own right. The cruiser crowd may well lap it up, but for those (like me) a little outside of that, the lure of that iconic engine in an adaptable package, plus 2k in change with which to meddle and evolve the bike to your particular desire, may well be the winning ticket.