The White Industries LMDS is one of the most original designs of modern derailleur history. LMDS stands for Linear Motion Derailleur System. At the height of the US boom in CNC derailleur manufacture, Doug White of White Industries approached Frank Berto to help with the design of the definitive mountain bike derailleur. Determined not to travel the well trod path of copying a Suntour V GT or Shimano Deore XT, Frank Berto, as only he could, built a Meccano prototype loosely derived from the Cyclo Standard, (or, perhaps more correctly given the tension spring, from the Cyclo Oppy).

The body of the LMDS travels along two stainless steel rods on some kind of fantastic ball bearing race system. It is unsprung and is pulled to and fro by a double cable system (actually a single very long cable that loops around a pulley wheel at the inner end of the rods). The whole shooting-match is machined from the finest materials to the closest tolerances.

The LMDS is a subject of controversy amongst mountain bikers who like the exotic. For some it is simply the best derailleur system that the universe has ever seen - and the only example that I have ever ridden was excellent (although I couldn’t say whether it shifter better than Deore XT). 

However there is a body of opinion that rates the White Industries LMDS as worse than useless. Complaints include:

1. •That setting up the derailleur is extremely difficult.
   

2. •That the very long cable is hard to obtain (it has a very small spherical nipple).
   

3. •That the very long cable is too thin (in order to flex around the roller) and quickly stretches.
   

4. •That it takes three different Allen keys to change a cable - and if you try doing this on the road you always lose the tiny bolts that hold together the twist grip.
   

5. •That the tiny adjustment screws are too fragile - particularly the exposed low gear adjustment screw.
   

6. •That it is crazy that a derailleur covered in Allen bolts has a hex headed aluminium hanger bolt - just waiting to get its corners rounded off.
   

To my mind the White Industries LMDS is, on the one hand, the perfect derailleur for that (significant) group of cyclists who love their bicycles as an expression of engineering elegance. These guys (and they are mostly guys) actually enjoy cleaning and lubricating their transmissions, and like nothing better than using three rarely needed Allen keys for a simple job (what’s the point of owning all those hundreds of top quality tools if you never use them?).

If, on the other hand, you are one of those mountain bikers who sees your bike as simply a tool to allow you to express your athletic prowess and to enjoy the great outdoors, then the White Industries LMDS will offer you significantly less utility than a mid-range Shimano.

Nevertheless, the White Industries LMDS remains beautifully made, spectacularly light and genuinely different. Kudos to Frank Berto and Doug White (as the camera dudes like to say on dpreview.com).