All the proto bits are individually numbered by hand

A while back we brought you our first impressions of Shimano’s all-new XTR group after a couple of days with it in Wales. A proper production groupset is on its way to us for the full BM test treatment right now, but in the meantime we thought that you might like to have a look at some stuff that doesn’t get out in public all that often.

Lurking in a plastic crate in the back of the Shimano tech support truck were these prototype XTR parts, which give a pretty interesting insight into how bike stuff gets from vague idea to production metal. Join us on a journey of the not-quite-finished…

A couple of views of an early prototype XTR Rapidfire+ pod (complete with manky bits of cable where they were taken off a test bike without much in the way of finesse). The key functional elements of the shifter (adjustable clamp, two-way release lever etc) are there but not much attention has been paid to the styling at this stage. Note that the levers are close to the final shape, though – the idea is that these should feel and work like the end product even if they don’t look like it. All the metal bits are individually machined from aluminium stock, while the plastic cover underneath is the output from a rapid-prototyping machine that does clever things with polymers and lasers.

Like the shifters, these proto brake levers are designed primarily to work – once the actual mechanics of them are sorted out, the styling can be worked on. The calipers are pretty close to final, though – they owe quite a bit to existing Shimano products, so there’s less development necessary.

These cranks aren’t so much a prototype as a mule. This started off as a stock XT chainset, but with a different axle and a modified left-hand crank to test XTR’s revised crank mounting. It’s also fitted with XTR carbon/titanium chainrings. The finishing touch? The “R” added to the crank arm graphics with marker pen. Class.

Finally we have three versions of the XTR rear mech from various stages of development. The distinctly rough-hewn first one is an early proto just to make sure all the pivots and angles are right and that the shifting will work as desired. The second one is a little more advanced – the designers are working on the forgings and tweaking the shapes. And the third one is perilously close to the final production item – it’s just a bit blacker than it ought to be.