Tag Archives: Suntour

The Bridgestone is Back!

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It’s been a typical gloomy winter in Portland this year, with plenty of grey, stormy days.  Normally I ride my winter bike – a 1987 Panasonic MC7500 which I converted to a commuter bike quite a while back.  But this winter, the bike just didn’t speak to me as it has in the past, and I’ve decided to sell it and let someone else enjoy its funky delights.  I had previously stripped the Bridgestone MB-3 bike down to the frame a while back as well, as the build I did at the time also didn’t really stick.  I guess I am fickle!

So, for this iteration of the 1989 Bridgestone MB3, I decided to focus carefully on what would make the bike a keeper for me.  As I’ve aged, I find that I want lower gearing, and I’ve also come to prefer index-style rear cassettes combined with friction shifting.  For commuting and roaming weekend rides I love the silent and immediate shifting this set up offers.

Of course, that meant using some NOS Suntour shifters mounted on V-O’s thumbies, which allow you to mount any brand of shifters so you can be as creative as you like (unlike Paul’s thumbies which are brand specific).  I also used a new V-O Tourist bar, which has a nice shape without a huge amount of rise.  For this build I did not cut the bars down because I wanted a little more room in the grip area.

I also used some NOS Suntour brake levers that came complete with the original cables and special ferrules.  These brakes have reach adjustment and are spring loaded, with a comfortable cover over the lever portion.  Very nice.

Continuing on with my Suntour NOS theme I used the Suntour XC cantilevers which I had used on the original build.  The set up for these is a bit of a learning curve, as the spring tension is adjustable on only one side.  What I’ve learned is that positioning the brake arm on the adjustable side so that it matches where the other non adjustable side falls is the quickest way to get the tension on both sides to be equal.  Once properly set up the brakes are not grabby and easy to modulate.  For the rear hanger, I used a model that has an angle adjustment screw which really helps with setting up cantis and centerpulls.  It is a very short hanger, which works very well with smaller frames, allowing more cable travel from the straddle cable.  You generally need at least 20mm of travel, but I’ve got lots more than that by using this shorter hanger.

At this point, my love affair with Suntour had to end.  I had originally thought about using some NOS BL Black derailleurs that I had in my collection, but they did not work well with my chosen 8 speed 12-34 cassette.  So, I went with the excellent offerings from Shimano:  a new long cage Deore rear derailleur mated to a NOS 105 derailleur up front.  The crankset is a new V-O 46/30 double.  This gives me a gear inch range of 22-95.

The wheelset is one that I built a while back – Shimano Ultegra hubs laced to Mavic X221 rims.  I’m trying out these Schwalbe Kojak 35 mm tires, which are tread-less.  They are designed as a road tire, but with extra flat protection for commuting.  They are lightweight at 295 grams each.  And they roll very well, a bit faster and quieter than the Pasela’s I usually use for commuting duty.  So far, I really like them which is amazing as I usually have nothing good to say about Schwalbe tires.

This model Bridgestone was built with Ishiwata triple butted 4130 Cro-Mo tubes, with a Cro-Mo unicrown fork.  The frame is lugged and has a couple of degrees of slope in the top tube, enough to allow a large enough head tube for lugs in this small framed bike.  The understated (for the 80’s) black and grey paint is still in excellent condition and the bike’s logos are vibrant and intact.  There are two bottle cage mounts, as well as fender eyelets and rack mounts on the seat stays.

I decided to finally use this wooden fender set that was given to me many years ago.  I never had the right project for them so they sat unused in my fender drawer.  The normally torturous process involved in setting up fenders and racks was no less so with this bike.  The wooden fenders have an unusual stay attachment with a shouldered washer that was difficult to master.  The fenders were originally designed for 700c wheels, so I’m letting them bend into place before I cut down the projectile-like stays to the right size.  Likewise, the rear rack required a bit of problem solving as I wanted to use this classic Italian Vetta rack with its single brake bridge stay.  Unfortunately the straddle cable for the cantilever brakes landed right in the path of the brake bridge stay, so I got creative and found a way to use the bike’s seat tube rack braze-ons with this vintage rack. 

The relatively short chain stays on this bike (42.5 cm) meant that I needed to use a narrow pannier to avoid heel strikes when pedaling.  These older and very inexpensive Avenir bags came to the rescue.  Although small, they can hold more than it would seem at first glance, so I plan to use them throughout the winter, as they are also reasonably waterproof.

 

On the bike’s first test ride I had an unpleasant experience.  While riding through Mt. Tabor park, an unleashed Pitbull escaped from the off-leash area, charged toward me with bared teeth and proceeded to latch on to my ankle as I was pedaling uphill.  After kicking him off (along with various shouted expletives), the dog then went for my wrist and at this point I had to stop pedaling to avoid crashing.  Fortunately, the dog’s apologetic owner arrived on the scene and finally got the dog leashed.  Because it was a rainy day I was wearing rain booties over my shoes, plus rain tights, and thick wool socks and so thankfully I had no broken skin on my ankle or wrist, and no trip to the emergency room was required.  The bike performed very well through this emergency and I did not crash.

Is this bike a keeper?  So far I’m thrilled with the silent, stable ride, the smooth shifting, and the lower gearing for hill-climbing.  The bike looks beautiful and has already garnered compliments. Hopefully I’ve landed on a winter bike that will keep me going for the years ahead.  We’ll see!

Setting Up SunTour Cantilever Brakes

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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.

A 1975 Centurion Semi Pro

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I’ve finished my re-interpretation of this 1975 Centurion Semi Pro, with today’s late fall Pacific Northwest sunshine providing warmth and dry roads for its first test ride.

1975 Centurion Semi Pro in original configuration

After purchasing the bike a few months ago, I disassembled it, assessed its frame and components, and then re-built it as a city commuter, to reflect the kind of riding I currently enjoy.  The frame was free of rust, and in unusually nice condition for its age.  This Centurion Semi Pro had been upgraded at original purchase to Shimano Dura Ace components and a 27″ tubular wheelset.

I kept as much as I could of the original Dura Ace components, but I knew that I would replace the wheelset, not wanting to ride on 27 inch 20mm tubulars through downtown Portland.  At first, I considered a 650b conversion as the best option for adapting this bike to my riding style.  But, the close clearances on this frame designed for 27″ wheels meant that I was looking at an 87mm brake reach to accomplish the conversion.  While possible, this amount of reach is not ideal.  There are brake calipers which have enough reach to accomplish the conversion, but they are not in my constellation of desirable components.  Instead, I converted it to 700c, using the existing anodized Dura Ace calipers, which had plenty of reach for a 700c wheelset.

Campagnolo Record quick release skewer, SunTour GS Chromed dropouts with adjuster screws and single eyelets.

Mavic Open Pro 700c rims

Campagnolo Record hubs

Pasela 700 c 35 mm tires

And that wheelset turned out to be one that I had built a while back and which I had used on my old Davidson:  Campagnolo Record 36 hole hubs built up on new Mavic Open Pro rims.  The blue rim logo picks up nicely on the Centurion’s sky blue frame paint. The tires are Panasonic Pasela 700 x 35. They have a tread pattern which is different from all other Pasela tires.  The big tires on 700c wheels make for a tall bike, which I noticed throwing a leg over and while riding in its new upright position. Being visible is a plus for cycling commuters.

Blackburn rack with single stay attachment to the brake bridge

For the modifications to convert this bike to city use, I selected some of my favorite components:  a Stronglight 99 crankset with 48/37 rings, a SunTour gold 14-32 freewheel, SunTour bar mount ratcheting shifters, Dia Comp brake levers, and french Sufficit grips glued to a steel Northroad bar.  Most useful was a NOS Jim Blackburn rear rack with its single stay attachment to the rear brake bridge – a great solution for bikes without rear rack mounts.

When I was selecting and testing components, the original Shimano Crane GS rear derailleur presented some problems:  the amount of tension needed to shift to larger rear cogs was significant.  And that tension helped to explain the scratch damage on the frame from the shifter clamp moving down the downtube.  I found that the original Shimano Crane GS rear derailleur was not performing as expected.  I disassembled the derailleur (thank you RJ the bikeguy) and found that the springs and pivot bolts were caked in grime and dirt.  However, after cleaning and lubrication, the Shimano Crane derailleur still requires a significant amount of cable tension to move the parallelogram.  Shifting the bike today on its test ride required overshifting on the up shifts, and a lot of adjustment on the downshifts.  I expect that I will probably replace the Shimano Crane with a SunTour derailleur to improve the rear shifting.

When I ventured out today, I planned on riding my usual route around my hilly neighborhood. I enjoyed getting out for a ride on this Centurion Semi Pro. There seemed to be almost no interference between my crank inputs and the bike’s outputs.  The ride was smooth and effortless.  The way back home to my house involves choosing among several different routes, varying in difficulty.  With this bike’s easy pedaling, I chose the most difficult route home, one that I have dubbed the “TDF” route, with its cobblestones and steep inclines.  That’s a route I only ride on my ALAN or Guerciotti – lightweight and high performance bikes.  So, even as converted to a city style bike, this Centurion Semi Pro has impressed me.