Projects

Retro-direct experiment complete

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.


retro-direct harry_quinn 8212_1

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

This entry was posted on Friday, January 16th, 2009 at 11:32 am and is filed under Brian's Project. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.

14 Responses to “Retro-direct experiment complete”

  1. chris says:

    January 16th, 2009 at 3:57 pm

    It totally feels weird pedaling backwards but wow does it LOOK weird to the casual observer. You know how it looks funny watching someone on a fixie really wrestling at slowing down by “back pedaling?” Well this really is back pedaling. That takes you forward. It’s blowing my mind.

  2. emily says:

    January 17th, 2009 at 1:13 pm

    I want to try it out!!! Looks awesome.

  3. Tony says:

    January 18th, 2009 at 9:55 pm

    Damn, I want one! I wonder if any of the local bike makers in portland (oregon) could make me one for my bike.

    nice work!

  4. Jon says:

    January 20th, 2009 at 6:58 pm

    I need to see this in action. When I stare at the gears I continuously waver from “Aha!” to “Huh?” Can’t wait to see this!

  5. Apples says:

    February 11th, 2009 at 6:39 am

    So what you’re saying is… if I pedal backwards, I go forward. But if I pedal forward, I got forward…?

    Seriously? Can you coast too? It would seem like… maybe? My mind is completely blown about this.
    Since the “backwards” gear is lower, do you pedal backwards to go uphill?

  6. admin says:

    February 11th, 2009 at 6:09 pm

    Yeah, I totally pedal backwards to go uphill. It’s like everything I know is wrong.

  7. Skott says:

    May 7th, 2009 at 3:46 am

    This is really cool. Can you add more detailed images regarding the rear hub assembly for us in Oz?

  8. Flower says:

    May 24th, 2009 at 11:49 pm

    Pedalling backwards uphill is a REALLY strange feeling & goes against all logic because you are standing with your weight on the pedals & putting the weight into the back of the bike. I switched mine on the advice of other retro-direct riders & now pedal backwards most of the time in the higher gear, so that pedalling forward uphill feels far safer, more logical & less painful…

  9. Pete H. says:

    November 16th, 2009 at 5:42 am

    Obsession is right! What an amazing, elegant hack!

    I discovered retro-direct gearing just the other day on the web and am now awaiting delivery of a few parts to implement my own. I had a bottom-bracket cup, and with a lot of singlespeed freewheels lying around found that they do indeed screw right together.

    A KORE chain-tensioner looks to be the simplest way to hang the chain-turning pulley, like this guy: http://preview.tinyurl.com/yhowg4e

    That’s pretty much the specialized parts needed to roll your own… my last question is the directions to assign to the gears, but like Flower, and the Zoobomb guy from the link above, and another blogger, I believe I’ll make the low gear the forward-pedalling one, for starting out, hill-climbing, and slow cycling. The backward gear for cruising may also put less stress on the left pedal (I’ll use Loctite, too).

  10. Aaron says:

    August 6th, 2010 at 9:35 pm

    Nice Work!

    That’s a beauty…I know this is an old page, but I hope you still check it!

    Talk about obsessed, I rode one a while ago…and they are just the coolest thing. I usually ride a 36″ uni, but looking for something a little easier to commute to work with and still want to be, you know…different lol. Main reason, it’s difficult to make left turns on the uni in traffic (have to dismount at red lights…between cars, then remount). Anyway, I’m working with someone to build a retro, and I’m looking for any pointers anyone might have (parts, gearing, crank length, good conversions, etc…).

    If anyone can help, please e-mail me at DNut10@yahoo.com

    If you are reading this…it’s because you’re awesome, Go Retro!

  11. Ben says:

    December 8th, 2010 at 12:45 pm

    If you’re still checking comments,

    How well did the static idler pulley work? Most rd’s seem to use sprung chain tensioners, but they don’t seem necessary.

    -Ben

  12. admin says:

    December 8th, 2010 at 4:39 pm

    The spring chain tensioner would be nice but not necessary. Definitely necessary if you have two chainrings.

  13. luckybk says:

    August 29th, 2011 at 6:59 pm

    Your build looks super clean and fun.

    I am very interested in this retro drive idea for a frame I have lying around.

    I have noticed in some other peoples adventures with ‘homebrewing’ their own retrodrive, a common problem being chain rub & unwanted derailment. How has yours fared in this regard? Does it happen if you pedal super hard? Any tips for prevention? Thanks!!

  14. admin says:

    August 30th, 2011 at 9:01 am

    Hi Lucky,

    Yes, chainline is crucial but I dimpled the chainstay to avoid any rubbing. Chain tension is very important too. Some opt for a spring tensioner which is something I would consider for the next one. There’s a good article about retro-directs in Boneshaker 42-500.

    Good luck!
    Brian

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