Setting up Centerpull Brakes

Center pull brakes are often standard equipment on vintage bicycles. Their design can allow more clearance for fenders and wide tires, and based on where the pivots reside, they may have more mechanical advantage than standard sidepull brake calipers.

But, centerpull brakes are sometimes viewed as more challenging to set up than side pull brake calipers.  How long should the straddle cable be?  How close should you set the brake pads to the rim? What is the ideal angle for the straddle cables?  How much torque should go on the mounting bolt?  What about lubrication of the pivot points and cables?  Should the straddle cable be thick or thin?  And, most important, how can you eliminate brake squeal on these often very noisy calipers.

Brazed on centerpulls – a 1978 Centurion Pro Tour

For over twenty years I cycled on a bike that had the best centerpulls you could find – brazed on centerpulls were standard equipment on my 1976 Centurion Pro Tour.  While this advantage went unnoticed by me in my youth (I had nothing to compare this to), I have definitely noted the extra care and adjustments needed to the bikes I currently ride which feature center pull brakes, but which are not brazed on to the frame.  The above photo shows brazed on Dia Compe centerpulls on a 1978 example of a Centurion Pro Tour.

1953 Follis branded Jeay brakes

1947 Peugeot with Jeay centerpull brakes

Brazed on centerpulls have been around for a long time.  The above examples show Jeay centerpulls on a 1947 Peugeot, and a more custom example from Follis on a 1953 frame.

If you are ordering a custom bicycle, you can most definitely specify for this braze-on feature.  Using the brazed on version of centerpull brakes keeps the brakes centered, and undoubtedly improves the overall performance of the brake.

What is the best way to set up centerpull brakes?  Sheldon Brown offers some guidance, as well as Park Tools.  But the instructions on these sites do not address some puzzling issues such as the proper length and angle for the straddle cable and the proper distance of the pads to the rim. Nor is the cable width and pivoting characteristics of the straddle cable discussed (a la Mafac).

For the question regarding the ideal pad distance to the rims, I can turn to both my own personal experience, as well as to one of my favorite resources – Glenn’s New Complete Bicycle Manual. The distance to set the pads to the rim is recommended at 1/8 inch, according to “Dr. Coles” (aka “Dr. Glenn” – the author whose white coat visage inspired my affectionate homage). That’s about 3 mm.  Seems about right to me, based on my many decades of cycling with centerpull brakes.

Rebour drawing of Mafac centerpulls with extra long straddle cable

The length and width of the straddle cable is another important element to consider when setting up these brakes.  For Dia Compe and other non-Mafac centerpulls, it may appear that you have no choice in selecting the straddle cable, but these cables actually come in all different lengths, not just the one included with whatever caliper you are working with.  The angle and width of the cables can impact the performance of the brakes.  More flexible and moveable cables (a la Mafac and Compass) will provide better performance. One of the nice features of Mafac brakes is that the straddle cable is actually a shifter cable cut short, so it is easy to replace and adjust these straddle cables for Mafac brakes, at will.

The above Daniel Rebour drawing shows a custom frame with unusual braze-ons for the rear centerpull calipers, resulting in a very long straddle cable.  In my experience, the length of the straddle cable is not so important as its angle – a wider angle at the yoke being more advantageous.  The angle will decrease as the brake lever is applied.  Also, pads should be set parallel to the rims, and with no upward or downward angle for best results (unlike some cantis which may need a slightly upward angle).

For Mafac enthusiasts, one issue is the flex characteristics of the fork and seatpost hangers.  These hangers are not very stiff, so that when braking pressure is applied, the hanger can flex significantly, reducing the performance of the brake and providing for a “mushy” feel.  Because of this, I have sometimes replaced the Mafac hangers with more robust hangers on my bikes with centerpull brakes, and with good results.  The above photos show the Mafac hangers.

V-O brake pad holders with toe in adjustment.

V-O smooth post pads – non squeal variety.

Brake pads are important to any brake set-up. While Kool Stop does make Mafac replacement pads – both in orange and black compounds, I have found that I prefer using Velo-Orange pads for my centerpull brakes.  They are quieter and yet perform equally well.  I usually lubricate all the pivot points on any centerpull brake I am setting up, as well as lubricating the straddle cable and yoke.  It’s critical to check your cables and the bolts securing them for wear and proper torque on a routine basis, and if any cables show degradation, replace them immediately.  You never want to apply the front brake, only to have it fail. That’s 70% of your stopping power.

A 1953 Follis 650b

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Here is a very pretty 1953 Follis Mixte featuring Nervex lugs, Fratelli Brivio hubs, Mavic 650b rims, a Simplex Juy rear derailleur with 4 speed freewheel, and a number of other nice features.

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Follis was another highly regarded French builder, founded by Joseph Follis in Italy in the early 1900’s. In the 1920’s, the company established its headquarters in Lyon after Mussolini took power. During and after WWII, the Follis company expanded and began building all kinds of bicycles, varying in purpose and price range, many of which were re-branded by other marques.

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Bonjour, Nicole.

This Follis was owned by Nicole Montbarbon, who resided in Bourg, Ain, France. A clearly visible owner’s name tag was a requirement for all French bicycles during this era.  Nicole took good care of her machine.  Even though the finish is very scratched, the bike appears completely intact and all original, possibly even down to the Michelin 650b 44 mm tires, color matched to the white Sufficit grips and rubber block pedals.

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Mavic alloy rims.

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White rubber block pedals

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Michelin 650B 44 mm tires – heavily cracked sidewalls means they are not safe to ride and should be replaced.

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Follis branded Jeay style brakes, nickel plated.

These Follis Jeay-style brakes are a bit nicer design than others I have seen. The inner plate, which pulls up on the caliper arms when the brakes are engaged, has a groove for each arm to travel on, so they stay in adjustment a bit better.

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F.B. – Fratelli Brivio hubs.

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Nervar crankset

Fratelli Brivio hubs are a nice touch, though the finish is now gone.  F.B. was an Italian component maker who first built hubs for Campagnolo, among others, as well as under their own name.  Nervar cranksets are not as highly sought after as Stronglight and T.A., but can be equally nice.  This one’s finish is pretty bad off, and it probably wouldn’t be worth it to re-chrome it.  Instead, the patina adds to its vintage appeal.

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Minimal brazing for the top tube/seat tube attachment. Through the frame cable routing for the rear brake.

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Lined lugs.

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Brass barrel adjuster for the rear brake.

I have been amazed at the number of different ways a mixte frame can be configured. In this case, the twin sloping top tubes are hand bent at the seat tube attachment, where they are minimally brazed, before travelling back to the rear dropouts. The frame includes pump pegs, double eyelets front, single eyelets rear, and braze-ons for the shifter and dynamo.  However, this particular frame was not built with the highest quality workmanship.  Although the Nervex lugs are fancy, the drop outs are stamped, not forged, and the finish work on the ends is just so-so.  Even so, a cursory examination of the tubes revealed absolutely no dings or dents, just a lot of scratches and lost paint.

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The lighting system looks intact, except for some broken wiring.  The lamps and dynamo are branded SELF.  The lenses and reflectors are not cracked and have a fun art-deco look to them.  Note the yellow front bulb.

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Simplex Juy Bell Crank derailleur

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Rigid chain guard

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Simplex shifter mounted to frame braze-on.

The Simplex rear derailleur is frame mounted.  This model uses a “bell crank” to move the cage. I haven’t worked on this model before, but fortunately catalog scans are available from Disraeli Gears.

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This derailleur has open pulleys at the back of the cage, allowing you to remove the chain from the derailleur without breaking it, a helpful feature. The chain is a Sedis model Yellorex, which also appears to be original to the bike.

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Luna Model 122B leather saddle.

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Matching leather tool cases.

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Brass wingnuts, branded “L.P.”

I originally acquired this bike as a “donor” – to give me some needed parts for other projects I am working on.  However, given its completeness and classic beauty, I may change my mind and restore it.  Perhaps that would please Nicole, wherever she may be.  Nous verrons!