Wednesday, May 26, 2010

Conversion of a French road bike into a porteur: a preview

I've posted before (here and here) about various sub-projects related to my conversion of an old French road bike into a practical porteur.  Well, it's nearly done and I thought I'd give a preview.  Here's the bike, a 1972 Jeunet 630 road bike, in "before" condition:


What attracted me to the bike originally (beside the fact that it is my hard-to-find size) was its lightweight lugged steel frame and fork made from Reynolds 531 tubing, with somewhat relaxed angles and room for fenders, its lightweight aluminum and mostly French components, and its overall classic, French character.  I didn't need another road bike, but I was intrigued by the versatility and style of the classic French porteur bikes, so I decided I'd attempt to convert it into one:  a bike that's light, and therefore easy to carry up steps, one with adequate gearing to conquer the hills of Somerville, one with an upright riding position, one that can carry a bag of groceries or haul a box to the post office, and lastly--and most importantly--one that is comfortable, fun and stylish enough to be my daily rider.  I feel that the French porteur bikes, like the ones pictured below, integrate these features better than most bikes, and so it was that the porteur bike served as the template for my conversion:

1950's Motobecane porteur.  Photo courtesy JP Weigle via Flickr.

Modern iteration of the porteur:  handmade in the US by Curt Goodrich.
Photo courtesy spoke sniffer via Flickr.

Here's my Jeunet "after", newly powder coated in a matte, minty green (RAL6021). I've assembled it well enough to ride, but by no means is it completed. It's still missing lights (the subject of a prior post), and little things still need tweaking, like the brakes and the fender alignment.


Velo Orange, one of my favorite suppliers of classically styled bike parts and accessories, sell a beautifully crafted front porteur rack made from tubular stainless steel, taking all the design cues from the classic French constructeurs:


It's large and versatile, with pannier loops, mounts for lights, an optional side rail, and a neat mount for securing an elongated front fender (typical of old French bikes), to avoid rattling.  I haven't decided how I'm going to realize the utility of the rack-- I can add a basket, a crate, or a side rail... or simply use a bungee net to secure stuff. For now I have a single pannier attached to it, a repurposed old leather school bag that just happens to snugly hold a 13" MacBook. Perfect! And I have an old wine crate that I may affix to the rack... we'll see.


Also from Velo Orange are the handlebars, shaped just like the classic French porteur bars:  similar to English 3-speed handlebars (commonly known as "North Road" bars), but slightly narrower and with less rise.  Actually, the French porteurs used to use the bars flipped the other way around, to achieve more drop, but I have them in the non-typical orientation, flipped up to provide a more upright riding position.


I'll also use this photo to illustrate the French style "inverse" brake levers.  These are modern reproductions of old French brake levers.  The inverse design is ingenious, it makes you wonder why this design hasn't become the de facto standard among city-style brake levers.  With the pivot point placed at the end of the bar, it allows your hand to rest anywhere along the bar from the bend on back, and still reach the brake lever!

Originally the Jeunet was geared like a typical road bike of that era:  10-speed, with a double chainring in front and a 5-speed freewheel in back.  The outer chainring was usually large, typically having over 50 teeth, allowing the bike to go fast.


The porteurs had simpler gearing, usually a single, smaller chainring in front, coupled to a 5-speed freewheel.  This provided plenty of gearing for getting around town, but didn't allow the bike to quite reach road bike speeds.  Not having a derailleur also means being able to have a chainguard or chaincase-- another common and practical accessory of old city bikes the globe over.  Since I wanted a simplified gearing setup and the potential to add a chainguard, I decided to convert the double chainring to a single, making the Jeunet a 5-speed in the spirit of the classic porteurs.


So next on the agenda is to complete the lighting.  These are the headlight casings that I intend to retrofit with modern battery-operated LEDs:


They'll mount underneath the front rack, attached by bracket, similar to the ones in the Curt Goodrich example above.  I'll make a step-by-step write-up of the LED conversion the topic of a future post.  Until then, if you'd like to learn more about porteur bikes with tons of photo examples, check out this link.  Here are some more pictures of the Jeunet porteur:





11 comments:

Anonymous said...

Gorgeous! What a fabulous job you have done on this! Bike lust!!!!

Velouria said...

Fantastic, what can I say! This is my favourite of all your bikes so far.

margonaute said...

Anton,

The photos do not do this bike justice. It is truly gorgeous! So glad to see it in person today.

Ian said...

This really is beautiful. I like that you kept the original Atax? stem. cheers and thanks for the post.~ian (Melbourne)

Tom said...

Love the bike. I had a picture in my mind of the kind of bike I was looking for, and this is exactly it. I even thought about a downtube shifter because I wanted inverse brake levers. Although the combination of Dia Compe Guidonnet levers and bar-end shifters would probably look classy as well.

Thanks for the detailed info on your restoration.

Taiwoon said...

this is so beautiful! congrats on a nice ride. i also just restored my bike and it got all my teenage history.. do check it out and let me know ur comments!

http://smallwheelsbigsmile.blogspot.com/2010/08/new-old-bike-nob.html

regards
Taiwoon from Singapore

yakym said...

Great buildout... so inspiring, I'm converting my italian built marin to a porteur now.

only one question though, where did you find the headlight cases?

somervillain said...

thanks, yakym! i found the headlight cases on ebay. they were sold as a set of three. i used one as a guinea pig for the retrofit, and i used the other two for the actual conversion after working out all the kinks. it's worked out great and i'm happy with the outcome... i just have to find the time to photograph it, write it up and post it.

you're welcome to the third empty case, if you're interested. it has a minor blemish in the chromed plastic finish from a failed experiment at hot-gluing a battery holder inside of it, but if you want it, it's yours for free.

kurt said...

Where did you have your bicycle painted?

somervillain said...

I had it powder coated at Long Beach Custom Fabrication, in Plymouth, MA.

Jonah said...

I wish I had seen this before I sent out on my own conversion of a 92 schwinn paramount into a similar bike. I can't wait to check out the rest of your posts - looks like wonderful material. I'd love to hear what you think about the schwinn - I devised a simple, but I think elegant solution to carrying the bike up and down stairs - an old belt attached to the water bottle mounts. I wrote up this (very long-winded) blog post in the event another person was searching for info about such a conversion:
http://mceuro.blogspot.com/2011/05/jills-paramount-renaissance.html
Thanks again!

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