Easy Rider

The Harley inspires a zero-maintenance, belt-driven pedaler

By Berne Broudy Posted 03.30.2009 at 9:28 am 7 Comments

Inside Job An eight-speed gearbox in the rear hub is protected from the elements Brian Klutch

How do you make a bicycle that never needs lube, never leaves grease on your pants, and always delivers smooth pedaling? Simple: Ditch the chain.

For its new Soho commuter bike, Trek replaced greasy metal links with a dry belt. Unlike other attempts at such bikes, the Soho is silky smooth to pedal. And it’s the first to offer multiple speeds, using an eight-gear transmission inside the rear-wheel hub.

Get It: Trek Soho, $990 from trekbikes.com Courtesy Trek

Trek recruited Gates Technology, maker of belt drives for Harley-Davidson motorcycles, to fashion a belt from carbon fiber and rubber that’s squeaky-clean and doesn’t stretch out. The biggest challenge—a two-year endeavor—was designing the perfect fit between the teeth on the inside of the belt and the aluminum cogs on the crank and rear wheel. Make the teeth too long, and the belt would snag on the cog, slowing the bike down. Too short, and the belt would slip.

For its part, Trek engineered thick frame tubes on the back of the bike that won’t flex under hard pedaling and slacken the belt. So you’ve got a bike that’s not only easy to ride, but easy to maintain.

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7 Comments

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Spooky2

03/30/09 at 9:37 am

Now that is a great idea. I ride a bike and the chain is a weak link (pun intended). Hope to see more of this inovation hitting the streets soon.

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Amonra

03/30/09 at 1:49 pm

Yeah this is great, I have owned a few mountain bikes over the years and over time the chain wears down the gears, especially in the rear. This belt will obviously cause virtually no wear and tear on the gears... should be quieter, and from the looks of it smoother pedaling!

I like it!

"No matter how you push the envelope, it will still be stationary."

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motherblessing

03/31/09 at 6:29 am

actually the drivetrain wasn't developed for Trek but for Spot Brand. I have a belt drive on my Spot bike and it works like a charm, ultra-silent and maintenance free... never better

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buddyred

from mankato, minnesota

04/02/09 at 10:34 am

Wouldn't the belt slip if it was used on a bmx bike? I would love to find out because i'n sick of my greasy chain always needing oil and makink my pantlegs a mess. a belt would be wonderful.

Buddyred

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huffman

04/05/09 at 2:26 pm

The geared hubs are a throwback to the old 3 speed internal hubs (think late 60's Murry) but much better now. I went to look at the bike pictured in the magazine (gray frame, orange wheels) on the Trek website but it's a single speed. They have the correct one shown here.

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visualize

04/09/09 at 2:02 am

The sides of the belt are open, unlike a chain, allowing the possibility of it working its way over and slipping off. Also like the article said, the teeth cannot be too long or they snag, too short and the belt would slip. Something that is in a delicate balance between the two is subject to do both at some point or another.

Why were other companies so unsuccessful with their bikes? What could this company have done so differently? I am curious whether they just ignored the safety concerns and built it anyway as a gimmick.

I broke my jaw riding my bike when half a link broke and the chain slipped off. While I would like to find a chain replacement, I don't think this is it.

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Uncle

08/27/09 at 5:18 pm

Actually, belt drives on bikes have been around since the 1800's, but the belts always stretched more then a chain drive. Even the fairly recent Kevlar belts will stretch, but these carbon fiber belts are not supposed to stretch out.

That said, this is the first article I have seen a close-up of the hub. I am also concerned there is no apparent retainer to hold the belt onto the cogs (though it could have been removed for the photo shoot) and will want to try one out before I buy.