Cranksets,+Gearing,+and+Internal+Hubs

toc A new section on common options for BFERs in cranksets, rear hubs, and gearing option information.

Crankset options for BFER-Velomobiles
In many BFER-Velomobiles, the front crank is a single speed chainring, in part because of the focus on the electric drive in the in part to long chain length and limits imposed on a front derailleur in a velomobile.Here are some very mature options in front crank shifting that do NOT require a front derailleur and use internal planetary gear shifting.

Schlumpf Drives[[image:http://www.cyclemonkey.com/images/photo-sch-sd.png align="left" caption="Schlumpf HSD"]]
Schlumpf makes several different front crank drives with a maximum ratio of an amazing 2.5:1 drive ratio on the Schlumpf Mountain Drive. One signature feature of the Schlumpf drives is the "kick button" in the center of the crank that does away with the need for shifter cables on these 2 speed front cranksets. Schlumpf cranksets have a reputation for extremely high quality and reliabiity. That comes for a price, and starting prices for a Schlumpf drive are over US$750.

Schlumpf Resources:
 * Schlumpf Information web site
 * Schlumpf Drive FAQs
 * One Schlumpf vendor: Cycle Monkey

Metropolis Patterson Drives[[image:http://www.metropoliscomponents.com/images/Patterson.png width="350" height="290" align="right" caption="Metropolis Patterson Crankset"]]
Metropolis manufactures and distributes the latest design from Sam Patterson: the evolution of an internally geared front crankset similar to the Schlumpf drives. The latest is the Patterson Metropolis with a 1.6:1 ratio from low to high that is comparable to most 2 chainring front cranksets. These are more affordable than the Schlumpf at ~US$300, but require installing a second shifter and cables.

Metropolis Patterson Resources:
 * Metropolis product web site
 * Sam Patterson web site
 * One vendor: ModernBike.com

Internal Geared Rear Hubs
In the 1960s rear geared hubs became very popular on touring bikes but were limited for decades to 2 speed and 3 speed hubs. The advantages were many over rear derailleurs, but they were not very rugged and early versions required frequent refresh of oil and were prone to early failures if ridden hard and in a dirt prone environments. Recent advances in geared hub technology now have 8 and 9 speed hubs and the newer and still quite expensive continuously variable transmissions (CVTs).

Common internal geared hubs on BFERs
The most common internal geared hubs as of late 2013 are the 7-9 speed hubs from Shimano and SRAM. Geared Hub Resources
 * Shimano Nexus hub web site
 * SRAM hub web site

CVTs come of age
The NuVinci N360 is the latest in a line of CVTs from Fallbrook Technologies that provide a true alternative to the 7-9 speed cluster in a geared bike. The NuVinci line provides an effectively infinite number of gearing combinations on an internal hub that can be built into nearly any BFER or road or mountain bicycle. The Harmony controller was introduced in 2013 to provide a fully automatic shift system that matches the drive to a preset cadence the rider prefers, which can be shifted to manual mode with the rear N360.

Mid Drive CVTs
In 2012 a European company, Pinion, announced a product that provides a mid-drive CVT, the Pinion P1.18

Bicycle CVT Resources:

 * Fallbrook Technologies: Cycling part of NuVinci developer site
 * N360 Product Page
 * N360 Vendor: eBay (can you believe under US$200!)
 * Harmony: automatic shifting control with N360
 * Pinion product page