Monthly Archives: November 2018

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.

Barelli Supreme Pedals

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These pedals were included in my recent purchase of a 1975 Centurion Semi Pro.  The pedals were new to my knowledge base and were not only lightweight and beautifully made, they also spun more smoothly than any other pedal I’ve ever handled.  With a name like Barelli, I had assumed these were probably made in Italy.  But, upon closer examination you can see from the above photos that these pedals hail from Great Britain.  Taking to the internet for a bit of research provided some background on this one-of-a-kind component.

According to the site, Classic Lightweights UK, these pedals were first introduced in the 1970’s by Cambridge cyclist and engineer Geoff Chapman.  They were featured at the Milan Cycle Show in 1977, and offered at 47 pounds sterling which included a lifetime warranty.  I can’t think of any bicycle component made today that carries a lifetime warranty.  While the 1970’s were different times, offering a such a warranty back then was also unusual, especially for a component subject to as much abuse as the lowly pedal.

Barelli Supreme Aluminum Pedal Cage – catalog insert

Barelli Spec Sheet

While these pedals were typically offered with steel cages, my set has lovely aluminum cages which show very little wear.  The catalog shown first above, indicates that after their initial introduction, Barelli offered these lightweight cages, which brought the total weight for the set of pedals down to an amazing 336 grams.  The second spec sheet shown above is most informative in regard to the bearings, which according to the Barelli catalog are “Deep grooved ball races, giving double thrust and vertical load bearing.  Each bearing is completely sealed independently with special lubricant to ensure free running and reliability, requiring no maintenance.”  With that intriguing clue in mind, I decided to disassemble one of the pedals to see what’s what.

But before doing that, I  noticed that the spindles, which are nickel-chrome steel and still look new, have English left and right hand designations – “L” & “R” and an additional designation on the reverse side:  “D” and “S”.  French designations are given as “D” and “G”, so this has me puzzled.  And, these are not French threaded pedals.  Is this a reminder that the left hand side is reverse threaded?

The dust cap came off easily with a 14mm wrench.  Underneath was not what I expected to see.  There was no cone and spacers.  Instead, a locknut which came off with a 7/16 drive revealed a set of seals, strongly resembling a sealed cartridge bearing assembly.  Since I did not want to disturb the smoothness and perfect adjustment of these 40 year old pedals, I put everything back together for now.  After all, the catalog says “maintenance free” – and that appears to be right.  While I would love to use these pedals on any of my current bikes, they are designed for toe clips, which I no longer use.

One idea is to use them with half-clips which are not so difficult to engage while commuting.  Even without toe clips, one could still flip them around at stops to ensure your shoe is in the proper position, but the Barelli cages don’t have a tab that many other toe-clip pedals have which are designed to make it easier to flip the pedals to the upside.  Even so, it’s tempting to just give them a shot and see what I think, sans toe clips.