A Bike to Make You Smile

1987 Panasonic MC 7500

Last summer, I set aside my 1987 Panasonic MC 7500 frame, after transferring many of its components to a 1989 Bridgestone MB3.  I rode the Bridgestone through the summer and fall, but found myself riding it less and less, and ultimately it sat unridden since last December.  Although that frame is similar in size to the Panasonic, its geometry is slightly different, with a longer and sloping top tube and shorter chain stays.

 

You can see the slight differences in frame geometry in the above photos. The Panasonic is a more traditional frame, with more of the rider’s weight closer to the front end of the bike.  For commuting and all-round riding, I like having the weight more evenly distributed, especially given that I haul stuff primarily on the rear rack.

While frame size issues can often be overcome with the right mix of handlebars, stem, and seatpost setback, when a bike isn’t ridden, there’s usually a reason, and sometimes no amount of tweaking the components will solve the problem.

The Bridgestone didn’t make me smile.  So, with anticipation, I brought out the Panasonic frame from storage and began the process of bringing it back to life.  I first did a complete inspection of the frame and fork, cleaned all of the threaded surfaces, applied clear touch up paint where needed, and washed the frame.  Then I polished and waxed it (with several coats), and also treated the inside of the tubes with WD-40.  Then it was time to build it up.

 

I had some inspired moments, deciding to use some period correct Shimano cantilevers, which offer much better modulated braking power than the new Tektro’s I had previously used.  At the rear is a U brake, very fiddly to set up, but the Dia Compe set installed there works fine, so long as I set the pads very close to the rime.

I also decided to go with a double crankset, instead of the single chain ring I had always used when riding the bike previously.  Wanting to keep the weight down (smaller riders benefit greatly from weight savings) I selected a Shimano Crane long cage rear derailleur, along with the drilled Stronglight crankset that I had been using with the Bridgestone.  Velo-Orange porter bars, SunTour bar mount ratcheting shifters and a 6 speed Shimano freewheel finished out the build.

I reinstalled my hand built 26” wheels, which have a V-O rear hub and Quando front hub, both with cartridge bearings, laced to SunRims CR18 rims, which have held up well (although the rear Quando hub failed prematurely a few years back, replaced by the V-O hub).

 

I’m riding the bike this summer without fenders, because I’m researching some different fender options.  As I was getting under way for my first test ride I suddenly remembered that riding a bike with cantilevers, sans fenders, can be a safety hazard.  This is because if the front brake cable fails, the straddle cable can get caught up in the tire and fork crown and cause an endo, with related potentially dangerous injuries.  So, I hastily installed a tire saver to hopefully prevent disaster, even though my cables are all new, just in case.  A reflector bracket will also work for this purpose.

My first test ride on the new build was a delight.  This machine has carried me through cold, rainy winters, and has hauled a lot of groceries and garden supplies.  It’s a beautiful but well used frame, made with double butted Tange tubing, and featuring lovely chromed rear stays.  It’s 80’s color scheme is very visible, especially with the bright orange donor fork that replaced the original fork long before the frame came into my stable.  The bike is a good friend, and it does, indeed, make me smile.

Winter Ride Around Canby, Oregon

For the past several years, I have been drawn south to Canby from my Portland home base for winter cycling.

The Willamette River bends in a sharp s-curve at Canby before heading north toward its confluence with the mighty Columbia River.  Its beauty calls to me.  Fall colors, winter which promises spring, and the mesmerizing quiet of the ride offer a compelling contrast to cycling in Portland.

Today, I followed this little town’s cycling loop, rather accidentally.  I’ve ridden here a lot, and have ventured east of town up onto the plateau that sits above the river, and boasts the best of Oregon farm country – hazelnut groves, vegetable crops, and horses, cattle, sheep, and llamas a-plenty.  The basic route depicted above is a totally flat 11 mile loop.  It’s easy to add side trips to your journey, as there’s lots to explore around this sweet little town.

I’ve recently converted my 1980’s custom Meral 650b bicycle to more upright style handlebars.  On today’s ride one of my goals was to evaluate the bike’s ergonomics with the new Velo-Orange Tourist handlebars.

I wasn’t sure how to think about the brake levers for this bike – I wanted to stay true to its French heritage, and resisted purchasing new brake levers for the upright bar.  I finally settled on these black vintage Mafac levers.  I also removed 3 cm of bar material from each bar end of the V-O tourist bars.  I have found that modern upright style bars are generally too wide and long, and without cutting them down can give your bike an out of balance appearance, not to mention being uncomfortable.

To keep the bars free for additional hand positions I opted for stem mounted shifters.  These SunTour ratcheting shifters performed just fine, but I did have to adjust the position of the rear derailleur on down-shifts, whereas upshifts were near perfect.  I may replace these with some stem mounted Simplex Retrofriction shifters once I have a mounting option identified.

Oregon City Falls

The City of Canby sits along the Willamette River, upstream from the falls and locks at the historic town of Oregon City.  Today, the river was swift moving.  Maybe, I was too.

My 1980’s Meral is built with Reynolds 531 tubing, with a fully chromed fork (and with chromed main tubes underneath the dark lavender paint). That, plus converting the bike to 650b has made it one of my most treasured bicycles.  Happy riding in 2019!

Setting Up SunTour Cantilever Brakes

Black finish SunTour XC-Pro cantilevers with single spring adjustment at the rear of the arm

Champagne finish model with dual spring adjustment in front

Having recently set up two different versions of early 1990’s SunTour cantilevers, I thought it would be helpful to share my insights while they are still fresh in my mind.  While each of these cantilever models is called by the same model name, they could not be more different.  The champagne finish model pictured second has its adjusting springs and washers on top of each caliper, whereas the black finish model pictured first has only one caliper with an adjusting nut that sits below the caliper arm, but with two holes in the other caliper arm for additional spring tension adjustment.

The champagne finish model was more difficult to set up, which was counter-intuitive, given that each caliper arm could be dialed in for separate spring tension.  The above photo shows one caliper arm of the dual spring model disassembled.  SunTour provided a special cone wrench with each new XC-Pro Champagne finish brake set model sold (perhaps as a warning).

SunTour cantilever smooth post brake shoes

If you want a completely accurate engineering description of these brake calipers, you’ll find that at BikePro’s archived articles.

However, online guidance as to the particulars of setting up these brake arms is limited to the Sheldon Brown site, with its repellent advertising.  So, I consulted my print materials including my collection vintage mechanic’s manuals.  Oddly, the only really helpful print resource was Park Tools’ manual, which is also available online.

SunTour Model 59030334 Cantilever Instructions

Fortunately, both NOS brakesets I was installing included the manufacturer’s instructions. The dual spring adjustment champagne model, which was part of my Rivendell Appaloosa build, was my first attempt at setting these up.  The instructions include a helpful cutout to measure your straddle cable angle.  These dual spring XC-Pro brakes want a 90 degree angle.  I got pretty close to that, and called it good.  But, most illuminating about SunTour’s instructions for these cantilevers is the sequence of the steps, which doesn’t match my protocol about setting up brakes. SunTour advises positioning the brake shoes first, which in my experience is the very last step in any brake set-up.  After that, SunTour advises how to install the straddle cable (very low) so that the cable angle is correct (90 degrees) and so that the brake pads sit very close to the rim.  Then comes the spring tension adjustment.  Let’s just say that things did not go as planned when I initially set up these brakes on my Rivendell Appaloosa.  But, after some trial and error I finally arrived at the right spring tension adjustment, and the brakes are now performing well.

Spring tension 19mm nut under the brake arm

Only one arm has a spring tension nut.

Meanwhile, I set up a later version of these cantilevers on my Bridgestone MB3.  This XC-Pro model has its spring tension adjustment on only one arm, adjusted with a 19mm wrench from behind the brake arm.

Above are scans of the single adjusting nut model of SunTour’s XC-Pro cantilever instructions. This model uses a spring adjustment nut (19 mm) on one arm, and which sits underneath the brake arm.  These brakes allow for changing the spring tension by moving the spring from a low tension to high tension setting on the other brake arm, as shown in the scans above.  Setting up these single spring adjustment brakes ended up being less time consuming than their dual adjusting nut siblings.  The adjustment nut is only useful for centering the brake shoes, with spring tension controlled on the other arm with the hi-low setting. This model calls for a 96 degree straddle cable angle.  I didn’t quite achieve that with the setup on my 1989 Bridgestone, but they are still working fine with a slightly lesser angle.  I used the NOS SunTour brakepads (aka “bricks”) on the Bridgestone, after filing some material off their surface.  Even though not well regarded as brake pads, they are working nicely, and have not squealed (yet).

Need an IPA?

Older vintage cantilevers do not have spring tension adjustment.  So, if you needed to change the tension to improve brake performance you needed a 3 hole cantilever boss, or you needed to “strong arm” the spring to change its tension.  While that’s where newer cantilevers can offer improved braking performance, setting up these cantilevers correctly is another thing altogether.