Category Archives: 650B

Drum Brake Overhaul – Jack Taylor Tandem

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Drum brakes get a bad rap because they aren’t very effective when compared to rim brakes.  But, on vintage tandems, drum brakes are added to assist with rim braking. My 1977 Jack Taylor tandem features this front brake augmentation, which helps to keep the heavier and more powerful tandem bike’s front rim from overheating on descents.  An overheated rim can blow off a tire – not a good thing!

To accomplish this dual braking, the Mafac lever is modified to accept two cables – one for the cantilevers, and one for the drum brakes.

This bike’s drum brake hub is a cup and cone Maxi Car model featuring black dust caps.  The drum and pads were filthy dirty, and one pad had separated from the brake arms.  The pads were covered in grime and were glazed, but did have more than 2mm of depth meaning that they were still usable.

I cleaned and sanded the drum and the pads to smooth out the contact surface and remove the glazing. I also re-glued the separated pad to its arm, using an epoxy resin rated for extreme high heat (a JB weld product).  I clamped that with a C clamp and let it sit for about a week.  Then, it was time for reassembly.  Fortunately, when I disassembled the hub I took a series of photos at each stage.  I referred to this series of photos while I put the drum brake hub back together.

But, I also consulted Glenn’s Complete Bicycle Manual for an overview of the process.  This manual is the only vintage repair manual that addresses the overhaul of drum brakes in adequate detail.  Above are a few pages which illustrate the process.  In total, the manual contains 5 full pages dedicated to drum brake overhauls.  There are locknuts, spacers and nuts which need to be in the right place in order for the brake to operate as intended, which is why it’s so important to document the disassembly process.

This model of drum brake features only one spring, whereas some contain two springs.  When the arm is engaged, the spring opens and moves the pads outward toward the drum via a cam mechanism.

Once the hub was reassembled I put the wheel up into the dropouts and attached the fixed arm to the fork blade, using the original “88” rated bolt.  This designation signifies its tensile strength.

Having reinstalled the fork and headset, it was now time to install the stem so that I could set up the bars and brake levers.  I had noticed when working on the fork adjustment that there was no hanger for the cantilevers, and that’s when I remembered that this bike has a cable stop drilled on the stem.  I ended up having to gently re-tap the threads for the barrel adjuster, but the Milremo stem cleaned up beautifully after polishing it with Nevr Dull.

The next step was to set up the cable, and for that I needed to make sure I understood how the hardware should be positioned into the brake arm.

The original hardware’s end cap could not be reused because the cable would not come out, so I found a replacement and began the process of setting up cable tension.  It took several trial and error passes to get the cable tension correct so that the pads did not contact the drum when not engaged, but contacted the drum adequately when engaged without bottoming out the brake lever.

I made this short video showing the operation of the brake.  All looks good, and now it’s time to move on to the installation of the cantilevers. After that, I’ll continue on to the drive train, having previously cleaned, polished, and waxed the frame.  I’m glad to be making progress on this wonderful vintage machine.

 

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.