Wednesday, April 27, 2016

Belt Drive with a Gearbox

   Say you want to run a belt drive, but you still want to run some gears. The obvious choice is an internal hub, like the Shimano Alfine 11 speed. I have this on the cargo bike and it's great, if a little heavy.

Shimano Alfine 11 speed hub

   There are actually other options for geared riding with a belt drive. The Santos Travelmaster has a Pinion gearbox at the bottom bracket allowing you run some gears one a single speed-type set up! The Pinion gear box has enough gears to legally buy cigarettes (18), using the standard 1 gear = 1 year conversion chart found here. Here is shot of the bike all loaded up:


   This travel master is all set up for bikepacking with racks all over the place. The heart of the bike is the gearbox, located at the bottom bracket. A bike frame has to be specially built to run this system. 

Pinion gearbox

You can also see the belt tensioning device off the bottom:

Integrated tensioner

   The Travelmaster has a few odd features to see. The obvious is the gearbox. As this test indicates, they are not quite perfected, but offer a lot of benefits such as range of gears, weight and perhaps most important: minimal maintenance.
   Second, The version of this bike with an internal hub has an eccentric bottom bracket. The chain tensioning is handled by rotating the bottom bracket. On the gearbox version, they have a built in tensioner hanging off the bottom. Since there is so much going on at the bb already, why not use a sliding dropout or something? Plenty of sexy options for that kind of tensioner.
   Last, and maybe least odd, the front brake is tucked behind the fork. I'm not sure this is anything more than an aesthetic choice, as it looks cool and different.

Cool brakes too

   Are gearboxes the future? Get that weight down and some standardization on frame mounting and maybe they are! 

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