The Rohloff Speedhub is an internal hub gear, with 14 evenly spaced gear ratios and an overall range of 526%.
Neither Pashley, nor Alex Moulton bicycles provide a Rohloff equipped model, but options do exist if you want your ultimate bicycle to have the ultimate hub gear.
Avon Valley Cyclery, a Moulton dealer in Bath, produces the Moulton New Series Rohloff, and the Pashley Moulton Rohloff TSR.
The New Series Rohloff features Rohloff rear dropouts instead of the standard dropouts. The Rohloff dropouts allow sufficient fore and aft adjustment to achieve the correct chain tension, without the need for a chain tensioner. This is quite an elegant solution, though it will make it more difficult to retrofit a standard derailleur drivetrain in the future.
Photo: Avon Valley Cyclery
The Avon Valley Cyclery Rohloff TSR uses the standard TSR dropouts, and so a chain tensioner is used. This is not as aesthetically pleasing, but has the practical benefit that any standard drivetrain can be retrofitted, without any modifications to the frame.
Photo: Avon Valley Cyclery
You can, of course, purchase a Rohloff Speedhub, and fit it to your existing Moulton bicycle.
Rohloff have a useful wizard for choosing the correct version of the Speedhub for your particular situation.
There are a couple of downsides to equipping your Moulton with a Rohloff Speedhub. Firstly the high cost can be prohibitive. However, this is a very high quality piece of equipment, and failures have been few and far between. In the rare cases where problem have occurred, the service from the Rohloff factory is reported to be amazing. It is also worth noting that the cost seems more reasonable when compared with the cost of high quality drivetrains such as XTR or Dura Ace from Shimano.
Secondly, the issue of weight. While, again, the weight is not that high compared to a 27 speed drivetrain, but in the case of the Rohloff, all of the weight is unsuspended.