Archive for January, 2009

Retro-direct experiment complete

Friday, January 16th, 2009

My retro-direct obsession started in 2001 when I came across an auction for a Hirondelle bicycle on eBay. I had never seen a two-speed bike that pedaled backwards before and was intrigued. I didn’t win the auction but I was inspired to make one of my own. How hard could it be, right? With modern derailleur chains that can work with almost any chain line it really wasn’t a problem. The problem was that I needed to braze on a pulley to take the chain around a second independent spinning freewheel. At the time I wasn’t building bikes and I had little to no torch experience so I needed an alternate solution. The solution was a clamp-on Tektro chain tensioner for downhill bikes; My retro-direct dream came to fruition.

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At the time, all I had was my old Harry Quinn so I converted that. The two speeds were virtually the same: 46-18 forward pedaling and 46-16 backward pedaling. I rode it for a while but the gearing made it more of a novelty than anything else. Fast forward 8 years and I’m still contemplating building another one. I start by making a 3/32″ compatible freewheel with 24 teeth. Then I needed a test machine, so I found an old Biemmezeta on Craig’s List. It was a horrific neon yellow so there was no hesitation in stripping the paint right off. I dimpled the drive-side chainstay for chain clearance (wasn’t necessary on the HQ because the gears weren’t that different), then I cut a small slot, and I brazed in part of an old steel derailleur (third location was a charm). I contemplated putting a couple water bottle bosses on the inside of the stay to have a removable pulley but realized that since the stay was already looking like a pea-pod from the dimpling, I should just keep it as a dedicated two-speeder. I cut off the derailleur hanger, removed any unnecessary braze-ons, recreated the decals in Illustrator, and painted them on using a vinyl mask. The final product is a sharp-looking, obscure, Italian frame with an even more obscure drivetrain.

I should point out that the retro-direct concept is nothing new. The book The Dancing Chain by Frank Berto has extensive documentation on early versions and variations of two-speed, three-speed, forward, and reverse drive bikes. The idea of the “double-speed velocipede” was patented way back in 1869. It really didn’t become “popular” until 1899 when several companies began manufacturing them. Most notable were the efforts of Magnat & Debon, Hirondelle, and Terrot. With the dawning of the derailleur and internally geared hubs, the retro-direct and its two-speed simplicty had fallen to the wayside. It seems like nowadays only eccentric Sheldon Brown-esque types would be seen pedaling backwards on one of these archaic bikes. I guess I kind of fit that bill.

Here are some shots and specs of my project bike. It’s a 52-18 going forward and 52-24 in reverse. The freewheel is mounted to a 5-speed hub that was respaced and redished to 130mm with a solid axle. The rear hub has a 1mm spacer, 24 tooth freewheel, non-driveside cartridge bottom bracket cup threaded into the first freewheel, and then the second freewheel threaded onto that. Thanks to Jay Cloutier for inspiration, Frank Berto for the history, Chris Bull for the sweet sealed bearing pulley, and Nathan Trombly for the wheels. And for the record, yes, it does feel weird to pedal backwards.

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See the full slideshow

Circle A Cycles   |   523 Charles Street   |   Providence, RI   |   401.831.5221
background: mike looks at his new circle a single speed, excited to ride. (reveal)

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