We have these things that are equal parts magic and mechanics: internally geared hubs.
The magic is a deceptively simple bicycle with the full mechanical versatility of a conventionally geared bicycle. Internally geared hubs have been around for over 100 years but we're still introducing riders to them daily.
Yup, that's an 8-speed bike.
We offer several different internally geared hubs but by far the most popular is the Shimano 8-Speed. A single shifter accesses all 8 gears.
The process of shifting and riding is no different than any other geared bike, but instead of two complicated and often misaligned derailleurs, this hub has one single cable. Adjustment doesn't require any tools and is easily achieved by simply lining up the two yellow guides on the hub body.
Since the gears are protected from the elements inside the hub they require less maintenance and last longer. And because shifting doesn't require chain motion, as on an externally geared bike, it can be done any time. So if you get caught off guard by a red light or have to begin your ride on a steep incline you can instantly shift into the appropriate gear.
How'd they do that? Internal hubs work on a planetary gear system, similar to those found in automatic car transmissions. A central Sun gear is orbited by a smaller set of planetary gears. That system sits inside a larger gear ring called an annulus. All three elements can drive the wheel, creating three different gear possibilities. To ramp that up to 8-speeds you just add compound planets.
See, we told you it was magic.