Category Archives: 650b conversion

An R. Ducheron City Bike

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I’ve completed my rebuild of this lovely R. Ducheron.  When I received the bike as shipped from France it featured a newly painted framed, and a mix of components dating from the 1950’s through the 1970’s.  Determining when the frame was actually built has proved challenging, and for a long while I couldn’t figure out which direction I would go with my restoration.

Sadly, the bike was not shipped in a standard bike box, perhaps to save shipping charges.  And, the seller did not protect the drop-outs, so the fork ended up with some alignment damage, as well as the rear triangle.  A little strong-arming took care of this.  Then, I took to evaluating the components to determine when this bike might have been built.  The Normandy round hole hubs, with “Normandy” in quotes, and the style of Super Champion labels on the rims would date the bike to the 1950’s or early ’60’s.  But, some of the other components “original” to the bike were not consistent with this time frame.

After disassembly, the frame and fork weighed in at a respectable 5.5 lbs.  Rear spacing is 120 mm, with the front at 95 mm.  The effective top tube length is 53 cm, with a 49 cm seat tube.  With fork rake at 45 mm and the top tube angle measuring a slack 72 degrees, trail comes it at a very high 66 mm with its “original” 700c wheelset.

The style of the Huret drop-outs would mean that the bike had to have been made on or after the time that Huret introduced its first parallelogram rear derailleur in the late 1950’s.

But, this puzzling tab on the downtube, which would have been for aligning the clamp-on downtube shifters is accompanied by brazed on shifter bosses.  And that would mean that someone brazed the bosses on later than when the original frame was built.

But finally I decided to forget about all of that and just build the bike into one that I would enjoy riding on my Portland commutes, while remaining true to its French heritage.  While the bike was shipped with 700c wheels, it seemed to cry out for a 650b conversion.  To accomplish this, I used a set of 1960’s Maxi-Car hubs laced to Super Champion rims, along with Mafac Raid brakes.

For the drivetrain, I was stuck with Huret, but decided to use a more performance oriented component group than the Huret Alvit set which came with the bike.  I happened to have a matched set of Huret Success rear (titanium) and front derailleurs which were in good shape.

Since I wanted to have the shifters close to my hands, I installed some Shimano shifter pods (sorry!), and used some French threaded bolts to attach them to the Huret shifter bosses.  From there, using a wonderful hinged stem clamp from Rivendell, I mounted some Simplex Retrofriction shifters.  They work amazingly well with the Huret derailleurs, and make up for any shortcomings in the derailleurs themselves.

I installed a 5 speed Maillard 14-30 freewheel, which coupled with the original Stronglight 49D crankset provides a nice gear range for the hills I encounter on my commute.

The original Ideale saddle is a Rebour model, and it is in excellent condition.  It’s mounted to a Simplex SLJ seatpost, also looking quite lovely.

For the rest of the build I kept the original custom steel front rack with alloy stays, but discarded the oddball Ava stem (with its 7mm bolt) and Phillipe porteur bars in favor of these comfy V-O tourist bars with a tall Nitto stem sanded to French size.  I also discarded the original Weinmann levers in favor of the Mafac model, to match the Raid brakes.  The rear hanger already featured a Mafac piece for use in threading the cable from below as is needed on a step through frame such as this.

Here’s a photo comparing this bike to one of Ducheron’s competitors – Camille Daudon.  While the Ducheron is not a mixte frame, lacking the extra set of stays to the rear drop outs, I did not experience any unpleasant frame flex on my test ride today.

Riding the bike today I was pleasantly surprised to be enjoying the smooth ride, comfy Rebour-blessed saddle, and well-performing drive train, even though the Mafac brakes squealed like crazy (after adjusting for toe-in and sanding the rims and brake pads.)  So, I’ll be trying out some different brake pads, and I still need to mount the original fenders, and add a frame pump and bottle cage.  I’m looking forward to getting this bike out on the road and putting some mileage on this lovely artisanal masterpiece.

A Sunday Ride to Oaks Park

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Care for a dance?

Sunday rides are a ritual for me, even in winter.  But today’s glorious sunshine accompanied by a warm spell (60 degrees!) made getting out on a bike today a real delight.  I often ride out Springwater Trail, along the Willamette River, to visit Tadpole Pond, and the wetlands of Oaks Bottom, accompanied by a swing through Portland’s bustling Sellwood district.  Today, I decided to stop in at Oaks Amusement Park, one of the oldest continually operating parks in the U.S.

Being an amusement park, there are fun rides, including this swooping roller coaster which now induces a slight feeling of nausea, even though I once relished joining my pals for a spin on this magnificent, multi-colored joy machine.

But in addition to having the option to get sick, Oaks Park also offers picnic areas along the river, an historic wooden-floor roller rink complete with a Wurlitzer pipe organ, and is the home of the Herschell-Spillman Noah’s Ark Carousel, which is itself listed in the National Register of Historic Places.  I like visiting the park in the winter, when it’s closed, to enjoy the quiet river views and to marvel at the nostalgia-inducing feel of the place.

I’ve been riding my 1975 Centurion Semi-Pro, which I converted to 650b about a year ago.  I re-used the Sunshine Pro-Am hubs, laced to V-O rims, and installed Mafac Raid brakes to accomplish the conversion.

The Grand Bois Cypres 650b 32 mm tires are holding up well.  They are a nice alternative to tires offered by Rene Herse and Pacenti.  However, it appears that these tires are no longer available, although some models can still be purchased on eBay.  Below are photos of the bike’s features and current components.  In addition to re-using as many of the original Dura Ace pieces as made sense, I tried to stay true to the bike’s 1970’s roots.

Original Dura Ace FD

SunTour thumb shifters with bare helical casing

Stronglight 99 with 47/34 rings

Mafac black washer RAID calipers

Fender spacers – split to facilitate the installation of wider tires

Frame transfers – Dura Ace, USCF, and Tange Champion #1 tubing (faded)

Wrap-around seat stay, chromed

Jim Blackburn rear rack

Tange Falcon headset

My ride was capped off by watching a hawk flying overhead, chased by a murder of crows, only to land nearby with its prey in its talons.  My iPhone camera was no match for that photo opp, but the memory of that scene will live on, accompanied by many other memorable Sunday Rides.

 

Sunshine Pro-am Hubs vs. Ofmega Gran Premio

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Front hubs – Sunshine Pro Am on the left.

Rear hubs, Sunshine Pro Am on the right.

I recently needed to build a wheelset for a bike with 122mm rear spacing.  That meant that I could re-use its original Sunshine Pro Am hubs (spaced at 120mm on the rear), taken off the original tubular rims, or select a NOS hub set of similar quality and from the same era (mid-1970’s).  This might expand my hub choice options, because I could probably more easily locate a 126mm rear axle set, which the rear dropouts can easily accept without having to spread the rear triangle.

I ended up locating a 1980 NOS Ofmega Gran Premio 6200 hubset, with low flanges and 32 holes front and rear.  I had previously restored a few bikes that featured Ofmega components, so was familiar with Ofmega’s quality.

Ofmega Gran Premio 6200

Both sets were similar in weight, with the Ofmega set being only slightly heavier, probably due to the longer rear axle and fewer holes in the flanges. To verify my initial impression of the quality of Ofmega components, I researched the history of the company and discovered that its beginnings are murky at best.

According to VeloBase, the Italian component maker was founded by Mario and Dino Perotti sometime in the 1960’s, when they obtained patents for various bottom bracket designs.  It is posited by the disraeligears site that Ofmega had a relationship to the OMG Company, which in turn may have included the Gnutti brand in its portfolio.  By 2006, Ofmega appears to have finally shut down, although the exact date and cause of its demise is unknown.  For better or for worse, Ofmega is best known for its colorful and strangely shaped rear derailleurs, which evoke derision or amusement, depending on your perspective.

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Sunshine/Sansin’s history is similarly opaque.  I had believed that Sunshine was somehow part of Maeda and SunTour, but I wasn’t sure.  After a number of failed English language Google searches, I tried searching on Yahoo’s Japanese search engine, and came across a Wikipedia post (in Japanese) that I used Google translate to read, then took a picture of the brief entry, shown above. This confirmed that Sunshine was indeed a division of Maeda industries, a company with a very long history going back to 1912. This lead me to focus on what Maeda was doing in the 1970’s when my Sunshine Pro Am hubs were made.

From there I discovered that Howie Cohen of West Coast Cycles (and creator of the NIshiki brand in cooperation with Kawamura of Japan), was instrumental in encouraging Japanese component makers to bring high quality bicycles and components to the US market. Howie has passed away, but a website dedicated to his work lives on.  Howie had personal relationships and went cycling with many of the leaders of Japan’s cycling industry, and successfully convinced them that Americans were sick and tired of riding our heavy one speed balloon tired clunkers.  He turned out to be right.

I ended up deciding to re-use the bike’s original Sunshine Pro Am hubs, which I built using Velo Orange 650b rims.  I had a set of Grand Bois 32mm tires that I had originally planned to use for another project which never materialized.  The tires were relatively easy to mount, although it did take a few inflation/deflation attempts to seat the tires correctly on the rims.  As you can see from the above photos, the highly polished V-O rims look quite fine.

I’m glad I went with the Sunshine hubs – this is my new (old) 1975 Centurion Pro Tour, converted to 650b.  I will share more about the conversion in an upcoming post, but let’s just say for now that I am having a blast riding this well-handling and beautiful old machine.