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.

Braking News

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Recently I overhauled a few of the Mafac Racer brakes I had in my bin. Why? Perhaps to keep the demons at bay.  Anyone involved in the vintage bicycle “industry” (an apt word involving boatloads of industrious activity) knows that Mafac centerpulls are the best.  However, Mafac Racer brake calipers are ubiquitous, and therefore of very little re-sale value.  In a few thousand years, archaeologists will find these brakes in their dig sites and ponder their significance.

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One of the nice things about Mafac Racer centerpull brakes is that they can accept these little T.A. front racks, which bolt directly on to the arms.  On the above brake I have added a vintage looking battery powered headlamp, which clamps conveniently on to the supplied T.A. bracket.  The little rack is really only good for strapping on a rain jacket, loaf of bread, or tiny tool kit, but it does come in handy as a light mount, and looks very elegant.

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Mafac Dural Centerpulls

Overhauling brakes is really a very easy process, and simply involves disassembly, cleaning, polishing, lubrication, and reassembly.  I won’t detail the steps here, as there are many other resources on the web and in print (Dr. Coles to the rescue), to help you through the process.  If you want to spend far more money than your brakes will ever be worth overhauling your Mafac centerpulls, you can purchase a restoration kit from Compass Cycles for about $125.00 or so.   As I was overhauling these Mafac brakes, I found that I didn’t need to replace any parts – they just needed to be cleaned and lubricated. Mainly, the steel bolts and nuts can rust, and sometimes the red washers can disintegrate – although that is pretty rare.  These brakes were meant to last, and they do.  I didn’t need to replace any parts on the brakes I overhauled – including the washers, which really held up well over many decades.

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Mafac Raid Centerpull Brakes

One exception to the devaluation of Mafac brakes is the consumer demand for and rarity of Mafac Raid brakes.  These are extra long reach brakes that can be used to accomplish a 650b conversion.  It is difficult to find these brakes, and I have horded the few sets that I have on hand.

One of the things that fascinates me about Mafac brakes is how un-glitzy they are.  The stamped logos are odd and unprofessional-looking, and it seems strange to me that their model names include quotation marks.  Yet, engineering-wise, these are far superior to many of the competitors out there.  A rare example of substance over form.

1970’s Meral 650B Randonneur

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This bike came to me as a frame, fork, fenders, shifters, headset and rack.  It is a 1970s Meral 650b Randonneur. The Meral shop, located in France, built custom bikes up through the mid 80’s.  Their custom racks and fenders are as beautiful as their frames.  This frame features double rack mounts front and rear so that Meral’s custom camping racks could be added.  Note:  these photos were taken before final assembly and QC – the brake holders are mounted backwards.  The closed section of the holder should be facing the front of the bike, so that the pads don’t slide out!  (Everybody knows that, right?)

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The fenders are stainless steel – and looked beautiful after just a bit of polishing.   I needed a number of parts to get the bike completed, and ended up deciding to build the wheelset using a set of NOS Italian Gnutti hubs, since the spacing at the rear was 120 mm.  It can be difficult to find a nice wheelset with this spacing these days, and I didn’t want to cold set the frame to wider spacing, as I usually strive to keep a wonderful bike like this as original as possible.

2032 2026The hubs are very pretty and look a lot like older Campy hubs.

wheelbuildgnutti hubs

I used Weinmann 650b rims, and removed the labels for a clean look.  Even though this bike features through-the-frame dynamo wiring, I decided not to use a generator hub, both to save weight and to keep the bike simple and closer to original.  I am not a huge fan of generator lighting, and find that for the riding I do I can use simple, lightweight, and inexpensive battery-powered lights.

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The original cork spacers are still in perfect condition.  However, my fender line needs some more work.  Installing and fine tuning racks and fenders can easily take as long as building up the bike itself.  This frame is designed with tight clearances, so I could only use 32 mm tires.  I chose these Grand Bois Cypres tires from Compass Bicycles, and they are fabulous.  The ride is really just about the smoothest I have experienced.  The only down side may be their puncture resistance, which I haven’t put to the test.

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I used Simplex Super LJ derailleurs, which are not only beautifully made, but work perfectly with this drive train.  A Stronglight crankset and IRD 6 speed freewheel finish off the drive train.  The IRD is just a placeholder – I no longer trust these freewheels due to their high failure rate, which I have experienced personally on two separate freewheels in use for under a thousand miles.

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I used NOS Zeus pedals, which are some of the nicest I have seen, and Mafac levers to match the Mafac Racer centerpulls.  The bars are Nitto World Randonneur and the stem is a French sized SR.

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The frame was built with Columbus Aelle tubing, for a stronger frameset, or perhaps for a heavier rider.  Even so, the bike weighs 26.6 lbs, including the rack fenders, Brooks saddle and pedals – that is amazing.  The paint is still very vibrant and in beautiful condition.  More photos of this bike can be found on my FB page.