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.

Why I Love Cycling

1974 Touring Bicycle with fillet brazed joints – Photo credit – DeLong’s Guide to Bicycles & Bicycling.

In 1974 I was a high school senior, soon to graduate. I often rode to classes on my 5 speed derailleur bicycle, and that involved a number of steep hills, some of which I dismounted to ascend.  The bike I rode seemed incredibly incompetent, heavy, and badly geared.  At that time, I knew nothing about lightweight steel tubing, expertly brazed and filed lugs, and quality components.  I was riding the bike my parents purchased for me, after much goading on my part.  I can’t even remember if my 5 speed was a Sears or a Schwinn, but I think it was the former.  All I knew then was that I loved to ride bicycles, and wanted to be on my bike whenever possible.  My parents did their best to accommodate this odd request coming from their middle child – a daughter no less.

Baby blue Volkscycle

Upon graduation, my parents presented me with a beautiful blue Volkscycle. I was in heaven, as this was the nicest bike I had ever ridden.  After riding this bike in my college days in the late 70’s, I took a hiatus from school, and moved to the Oregon coast.  That was when my cycling energy surged. Every Sunday I mounted my blue Volkscycle and rode inland up Yaquina Bay, to Toledo, and back.  I rode this bicycle whenever I could, leaving my funky Datsun 510 truck in the carport most of the time.

After a while, I began to realize that the Volkscycle might not be the best bicycle out there for me. There was no internet at this time, so my knowledge came word of mouth talking to other cyclists, some of whom were part of the 1976 BikeCentennial.

Later, I acquired my 1976 Centurion Pro-Tour – a bike which really defined my cycling experience.  The frame was “too big” for me, and yet I toured all over the Pacific Northwest on this amazing bicycle.  I crashed it back in 1999, and that is what prompted a life long search for an equal partner.

But that never happened.  Instead, I ride on several bicycles regularly.  I have never found my one true love – the bicycle of my youth which comported me over miles of challenging terrain.  I don’t know what to think about why that is – but the upside is that I now enjoy riding a number of wonderful and interesting machines.

Cranky

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Vintage TA crankset with triple rings – 48/40/28.

The lovely & vintage TA crankset which I selected for my 1980 Meral 650b conversion has been an unusually frustrating interaction between the characteristics of vintage components and modern cycling requirements.  I chose this component for two reasons:  the crank arms were 160 mm, helping me to eliminate toe overlap on my 1980 sportif frame; and, since the Meral came with a TA bottom bracket,  I thought it would be nice to match it to a TA crankset of the same era.

But this crankset was problematic.  The big ring had a massive wobble that I had straightened a few times in my vise.  And, even though I use a similarly geared crankset on my Terry – a Shimano 600 with 48/40/30 rings – there was something about the TA rings that never really came together.  I never landed on my “cruising gear” even though I went through two different cassettes and two different front and rear derailleurs.  And, the drive train was always noisy, even after trying a few different chains.

Some frame-up builds come together perfectly, and some require more tweaking.  The Meral ended up being in the latter camp.

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Version 2 with TA 44/28 rings.

I decided that I might prefer a compact setup for this bike.  Since most of my current riding is commuting, it is important if only for safety reasons not to have to worry about gear selection while riding.  My other bikes provide easy and intuitive gear selection, so that my eyes can stay on the road.

A large tooth difference between the chain rings was de rigueur back in the heyday of French cyclo touring.  So, maybe it would work for me too.  I sourced NOS TA 44 and 28 teeth rings on eBay.  The rings are very pretty, and gave the Meral a real “French” look.

Unfortunately, for my kind of riding, the 28 tooth ring did not work at all.  Essentially, I was now riding a bike with a single chain ring plus a bail out gear, rather than a regular double crank which allows for even steps between the gears.  And, shifting between the two front rings often required a triple shift to maintain cadence. To make matters worse, the small chain ring was noisy in certain gears due to the extreme angle of the chain, front to rear and side to side.

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Version 3 with 44/32 rings.

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Beautiful new TA Pro Vis 32 tooth ring.

Not one to give up, I decided that a larger toothed small chain ring would be the answer.  I ordered a brand new 32 tooth TA ring from Boulder Bicycle.  The new ring is beautifully etched, and looks quite fine with the older crankset.  Even better, after installing yet another cassette (a SRAM 7 speed 12-32) to accommodate this new gearing, and adding a few links to the chain, the bike’s gearing is perfect for what I need.  My new gear inch range is 26 to 95, with even steps between the gears.  My shifting pattern is normal, and I have a cruising gear on my big ring that matches a comfortable cadence on a flat surface.  While I was at it, I adjusted the Simplex Super LJ front derailleur lower to make my front shifts crisper.  This front derailleur uses a parallelogram with an extreme angle, so in order to make it work well, it needs be about 1 mm above the teeth of the larger chain ring, rather than the usual 2 or 3 mm, to achieve ideal shifting.

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1980 Meral 650b as currently configured.

This bike was meant to take the place of my old beloved 1976 Centurion Pro Tour, which I crashed irreparably in 1999.  It has been a “long and twisted road” finding the right bike which can carry me not only to work and back, but to the undiscovered as well as the familiar. But this is what I have been yearning for.  A soul mate.