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c/bicycles · by RickyWars@lemmy.ca · 1y

Why it makes perfect sense for this bike to have two gears and two chains

https://arstechnica.com/cars/2025/02/why-it-makes-perfect-sense-for-this-bike-to-have-two-gears-and-two-chains/?utm_social-type=owned

29 points · 6 comments · view on lemmy.world

6 Comments

RickyWars@lemmy.ca · 10 pts · 1y (2 replies)

Interesting low-cost measure to not use a front-derailleur

The S2 model aimed to give riders an uphill climbing gear but without introducing the complexities of a gear-shifting derailleur, tensioned cables, and handlebar shifters. Engineers at SRAM came up with a solution that's hard to imagine for other bikes but not too hard to grasp. A freewheel in the back has two cogs, with a high gear for cruising and a low gear for climbing. If you pedal backward a half-rotation, the outer, higher gear engages or disengages, taking over the work from the lower gear. The cogs, chains, and chainrings on this bike are always moving, but only one gear is ever doing the work.

Probably not of much use but I thought it was cool

insomniac_lemon@lemmy.cafe · 1 pts · 1y

I mentioned it in the previous* thread in this community, but a similar thing to this that someone could DIY is retro-direct, which uses 2 freewheels and a longer chain (jockey wheel OR double chainring). This has no switching though, instead pedalling backwards is the other gear.

measure to not use a front-derailleur

Not really specific to front, especially when that's more of a thing for additional gear range.

* Title:

I saw Berm Peak made a fundraiser again with WBR, so I can't help but repost this article

kersploosh@sh.itjust.works · 1 pts · 1y

Sounds like it's essentially a Sturmey-Archer kick-shift 2-speed hub, but each gear outputs to a separate cog.

Ilovethebomb@lemm.ee · 8 pts · 1y

And it has a rack with a 200 pound capacity, too.

Very cool bit of engineering.

iii@mander.xyz · 6 pts · 1y

One for driving forwards. One for driving backwards.

Grass@sh.itjust.works · 1 pts · 1y

shifting like that kinda blows my mind

m4m4m4m4@lemmy.world · 1 pts · 1y
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