Category Archives: Jack Taylor bicycle

1973 Jack Taylor Revisited

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While I’ve been working on other projects, my 1973 Jack Taylor Tourist bike has been languishing in my storage area, along with far too many other bikes.  I thought it was time to bring it back out again for the coming spring weather, and that meant assessing why I wasn’t riding it so much anymore.

When getting the bike up into the shop stand I realized that I still hadn’t solved the ergonomic issues resulting from its large frame (for me).  Back in 2015 I had replaced the moustache bars with a more upright style, and a short reach, tall stem. But the bar shape didn’t really work for me, and I ended up setting the bike aside a few years back.

I needed some bars with a more swept back profile and with more rise, so I tried out these Sunlite Northroad bars, a set I haven’t tried before.  I cut them down about 2 cm, which turned out to be just right for this bike.  If I were using these bars on a smaller bike I probably would have cut more, but on this bike these bars look well balanced.  As part of the bar swap it was necessary to install new brake housing, which needed to be a little longer due to the swept back shape of the bars.

I made a few other changes as well.  The original Soubitez front lamp was held together with electrical tape and needed to be replaced.  I was able to find an exact match on eBay, shown above.  In the same purchase I acquired a NOS Soubitez dynamo from the same era. This one works more reliably that its predecessor and seems to have a little less drag.  I also replaced the pedals with a vintage Phillips French threaded set.  The pedals are very grippy, more so than the Lyotards previously installed.

When I threw my leg over for a test ride, I was reminded just how tall this bike is.  The bottom bracket height is a whopping 11.5 inches (29.2 cm).  That’s mountain bike territory, and definitely different than many of my other bikes.

This bike features 27 inch wheels rather than 700c. The rear wheel is laced to a Sachs Orbit 2 speed hub which takes the place of a front derailleur.  The big wheels roll smoothly and absorb road shock very well. They have never gone out of true since I acquired the bike 15 years ago.  I have found this to be the norm for any well built wheel, including wheels I have built myself.

The Sachs Orbit hub offers about a 25% drop from the direct drive gear.  As originally equipped, the bike had a 34 tooth chain ring on the front.  That was a bit low for me, so I replaced that with a 36 tooth version.  Gear inch range with this hybrid set up and the 14-28 cog set is 25-70.  Still pretty low, but with the bike’s front and rear racks, the low gearing makes it easy to feel comfortable hauling stuff and climbing hills at the same time!

I had previously changed out the original saddle for this vintage Ideale Model 75.  The leather was very stiff and unforgiving, which made for an uncomfortable ride.  After applying some Brooks saddle treatment and using a hair dryer to heat it up and work it into the leather, the saddle is now more supple.  With the newly installed upright Northroad style bars, this saddle style is perfect.  The springs do a great job at absorbing shock without being bouncy.

So, will I ride this bike more often?  I do think so.  Now that the ergonomics are right for me, the smooth ride quality and easy gearing will make it appealing.  It can handle any kind of weather, and even though I dislike sidewall dynamo lighting, getting caught in the dark will not be an issue for this bike.  This is a bike that can handle a lot of different riding requirements. The Reynolds 531 fillet brazed frame makes it responsive and light weight.  It’s also a beautiful bike and gets a lot of complements wherever it goes.

Eccentrics in Cycling

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1958 Eccentric bottom bracket on Rene Herse Tandem – Daniel Rebour drawing.

Eccentric bottom bracket on 1977 Jack Taylor tandem

As part of restoring my 1977 Jack Taylor tandem, I needed to rebuild the eccentric bottom bracket and set it up correctly.  There’s been a bit of a learning curve, since I haven’t previously restored a vintage tandem.

The use of an eccentric appears to first date to the steam engine era, to optimize the efficiency of a rotating shaft.  And eccentric bicycle components have been around for over 100 years.  Yet, it can feel foreign, and daunting to work on a bike that features this technology.

What is an eccentric?  The official definition from Wikipedia is:  “in mechanical engineering, an eccentric is a circular disk (eccentric sheave) solidly fixed to a rotating axle with its centre offset from that of the axle (hence the word “eccentric”, out of the centre).”  The above photo depicts an eccentric pedal design introduced in 1903. 

Here’s a dual eccentric bottom bracket that can alter the gearing ratio at the crankset, also introduced in 1903.

Fred DeLong’s experimental fork dropouts

Fred Delong even spec’d a bike that had offset fork dropouts, to enable him to quickly change his bike’s rake and trail characteristics.  Although not technically an eccentric, this dropout design allowed him to choose when to optimize for trail and wheel flop, as shown in the table above.  A similar result could be achieved with an eccentric front hub.  Currently, eccentric hubs are limited in application to the rear where they are used to adjust chain tension on fixed gear bikes.

My Jack Taylor tandem features an eccentric bottom bracket that is similar in design to the 1958 model depicted at the top of this post. The threaded portion features a T.A. spindle and cups. There is a single hole drilled into the offset section.  Newer eccentric bottom brackets have multiple holes drilled, so that a pin spanner can be used to ease the adjustment process.  I can’t quite make out the lettering on this model – does it say “Rogers”?

I had wanted to rebuild the bottom bracket while it was off the bike – one of the benefits of this design.  However, when it came time to install the rebuilt BB back into the shell, the fit was very tight and needed to be accomplished with a mallet.  Not wanting to damage the cups or bearings, I disassembled it and then rebuilt it again once installed in the shell.  But, when I did so I ended up positioning the spindle toward the front rather than the rear of the bike.  That’s not what you want, since the whole idea of this design is to allow one to move the spindle toward the front as the timing chain stretches with wear.

I made this video showing how to adjust the eccentric bottom bracket on a model where only one hole is drilled. After loosening the bolts in the shell, and using an Allen wrench inserted into the hole and then leveraging that with a heavy duty screwdriver against the spindle, you can get the eccentric positioned where you want it to be.  It’s clear to me now that overhauling a tandem is much more involved than a typical restoration.  Still, it’s been fun to learn new techniques.  I’m looking forward to the rest of the process.

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.