Mafac LS, LS 2 and LSX Brake Pad Replacement Part 2

Once the restoration of my 1973 Carre/Bertin C 37 was finished, it only took until the first ride to discover that the stock OEM Mafac pads were hard, high effort and unsatisfactory, especially compared to my 1960s C 37 equipped with Mafac Competition centerpulls with aftermarket black, Kool Stop pads. The search was on to try and find some kind of workable replacement.

Mafac Pad Front View

The Mafac LS series shoes are angled to create toe-in when the shoe is mounted on the LS caliper arm. In addition, they have a nut inside the OEM alloy brake shoe to accept the brake shoe attachment bolt which means a replacement pad has to have a notched or relieved center section to fit. See the accompanying photo on the right of the screen to view both of these features. Also problematic are the tight tolerances in the brake shoes and pads themselves. Having measured pads around the workshop like generics as well as Weinmanns, I could not find an exact dimensional match to the Mafac LS pads. Consequently, I decided to take the easy way out and simply replace the whole shoe/pad assembly.

The easy way was not easy. I ordered, on line, an inexpensive set

Mafac Pad Side View

of YST shoes with chevron shaped braking surfaces to echo the Mafac pad shape. Once they arrived, the steel brake shoes looked comparatively poorly finished and once installed they did not toe in well or look the part of a high end brake as one might expect with such an inexpensive product. However, the pad rubber was soft and once sanded clean of mold flash, the shoes did stop the bike better than the 40 year old OEM Mafac pads. Brake feel and modulation was not great but the bike would stop and did so with less lever effort than the original pads. Faint praise.

YST Pads On Jagwire Bag

Part 2 of the easy way was to order another shoe/pad combination set but this time from Jagwire in the Weinmann X pattern pad configuration. A big name in brake components should yield big results. Not so much. The Jagwires were better finished and cleaned up the mold lines with relatively little sanding. However, even with the LS caliper arms designed in toe, the Jagwires were still nearly parallel to the rims’ braking surfaces. The stopping was adequate, better than the OEM but not enough and they didn’t look right as mounted.

Part 3 of the easy way was an attempt to open up the Jagwire pads and extract one to test fit in a Mafac alloy shoe. The steel shoe on the Jagwires was reluctant to open which basically meant destroying the shoe to get the rubber brake pad out only to find the pad dimensions wrong for the Mafac shoe. At that point, I determined to find a pad that would fit the OEM Mafac shoe.

I searched through the technical specs for pads on the Kool Stop site but found nothing that looked close enough. While searching on the EBay USA site for Kool Stop, I came across a Scott/Mathauser ad offering Type M pads specifically for Mafac and and early Dura Ace. They could not have been for regular 4 dot Mafac centerpull brake shoes because the photos of the package clearly showed a Campyesque pad that looked quite different from the usual 4 dot Mafac pads found on Racers, Competitions and 2000s. So, I ordered a set which were quickly delivered from Ebay by Canada Post. When I opened the package, the Scott/Mathausers had a superficial look of compatibility with the Mafac LS OEM pads. Like I did with the Mafacs, I measured the Scott/Mathauser pads with my digital calipers.  I found the measurements to be slightly larger but within .5 to 1 mm of the Mafacs’ measurements. The one exception was the relief area on the top of the pad which in the Scott/Matthauser pad was 15 mm long compared to the 12 mm for the Mafac.

While I waited for the Scott/Mathauser pads to arrive by mail, I had been cleaning the Mafac shoes and removing the original pads. Removing the pads entailed levering them up at the end with a straight bladed screw driver followed by using pliers to wrench the pads the rest of the way out of the shoe. The shoes were wiped down and then run through an ultrasonic cleaner with some dish soap. The result was as set of clean shoes ready for the installation of the new pads. When the pads showed up, I checked the details on the reverse side of the plastic pack before attempting a trial fit or the installation.

Once the shoes were cleaned and ready, I attempted a trial fit of the Scott/Mathausers in the Mafac LS shoes. Even with the use of dilute dish soap as a lubricant, the pads did not fit into the shoes since the angle of entry of the pad was too extreme, the pad edge hung up on the round nut within the shoe and the pad would not settle under the rear stop at the back of the shoe.

The failure of the easy fit lead me to a few conclusions: that the .5 to 1 mm oversize difference of the Scott/Mathauser pads made a difference and you might want to do a little file work on the pads; the forward edges of the new pads need to be angled or rounded off to fit over the embedded nut within the shoe and finally, the rear tab of the brake shoe must be broken off to fit the new pad.

To get the pad rounded off like the center pad in the photo to the right, use a file or 120 Grit sandpaper as seen in the photo. It is also necessary to remove the rear retention tab of the alloy Mafac brake shoes. I tried a hacksaw but the result was poor and recommend bending the tab upwards with pliers until it yields and then snaps off. Once the retention tab has snapped off, put the shoe in a bench vice with padded jaws to avoid damaging the finish and take a fine file and dress the broken end thoroughly being sure it is de-burred and smooth to avoid fouling during the pad installation.

Be sure to carefully identify which end you will remove as the shoes are directional and the forward facing arrow must go to the front with a closed end but also to permit proper toe-in in combination with the LS caliper arm design. Once the shoes have been correctly opened and cleaned up, prepare a soap and water solution to act as a lubricant when installing the new pad into the Mafac alloy shoe.

Once you have lubed the inside of the alloy shoe, add the soapy mixture to the nose of the pad and to the crease along both sides. Slide the pad on an angle over the internal nut in the shoe until it is stopped by the front of the pad holder. It will now be sitting at an angle with the rear of the pad protruding from the  alloy shoe. Place the shoe/pad assembly into the padded vise jaws and slowly tighten down until the pad slips into place. (You may need to reverse the shoe in the vise to get the back section to fully seat.) Once the pad is seated, rinse the shoe to get rid of the soap solution from the installation and then follow the same procedure for the other three pad/shoe assemblies.

Having cleaned and dried  the assemblies, use your 120 Grit sand paper to abrade the braking surface of the Scott/Mathauser pads until the shiny surface is removed and the surface appears dulled to the eye.  Trial fit the retention screws and washers before doing an installation. The finished pad/shoe assembly should look like this:

 

The assemblies, once installed, should show an obvious toe-in when viewed from above. See the following photo:

 

 

Seen in profile, the installed assembly looks convincingly original and discreet except for that tell tale orange colour peeking through the brake shoes:

 

 

Conclusions:

The Scott/Mathauser M pad is the only one that I have found that installs properly in a Mafac LS, LS 2 or LSX alloy brake shoe. The fit is tight and installation could likely be eased by a slight filing along the edges of the pads in addition to the sanding described earlier. Toe-in is stock and so is the side profile appearance. Functionally, the pads are superb. There is no squeal, stopping remains higher effort than my Mafac centerpulls, as one would expect, modulation is easy and completely linear and progressive. Braking from the hoods is comfortably possible and is very strong from the drops. I highly recommend the conversion if you have Mafac sidepulls and wish to experience a major improvement in your braking quality.

Disclaimer:

The bike has not and will not be ridden in the wet so I cannot comment on that aspect of brake performance. Before the upgrade as well as after, the Carre/Bertin C 37 was fitted with Velo Orange lined cable housing and mandrel drawn stainless steel cables.

 

Carre Bertin C 37 Restoration Update

As you already know, a bicycle , typically, does not remain static unless it is a wall hanger used only for display. As cyclists, we tinker with our bikes, adjusting, substituting, modifying to adjust to changed circumstances, uses and needs. When I completed my Carre/Bertin C 37 restoration in 2014, I didn’t know it was a Carre built frameset but I was reasonably sure it would remain fairly static in its presentation. The just completed bike is seen in the photo below:

Carre/Bertin C 37 Oct. 2014

Since then, small changes have been made. I added toe strap buttons to facilitate tightening the toe straps, replaced the now, worn, dirty and faded red bar tape with more of the same colour from Tressostar, fiddled with saddle placement height and added the usual tool kit necessary for road riding. The result is this photo from a few days ago:

Carre/Bertin C 37 Dec. 2018

As well, there has been some curiousity regarding the drivetrain gearing. As mentioned in the original restoration series, the rear hub is a Maillard Helicomatic, a conventional style freewheel with an unconventional helical attachment screw thread. It is not a cassette as the hub bearings are

Rear Helicomatic Hub and Freewheel

discreet from the freewheel’s bearings which are in a separate body and not integrated with the hub. Details of this uniquely French system can be found at the Helicomatic Museum. This hub has a 120 mm over locknut width dimension which is the size of the now obsolete 5 speed conventional freewheel dimension for rear wheel dropout spacing. One other unusual aspect of this freewheel is that it is not a 5 speed as one would expect in a 120 mm spaced hub but is actually an Ultra/Compact narrow spaced freewheel instead with 6 cogs where 5 normally reside. Tooth configuration is standard period Maillard

 

and it uses a Sedisport black chain. And it shifts very well over its medium range cogs. The freewheel itself is 14-15-17-19-21-24T in sequence and since my area is relatively flat, it works just fine. The Helico is paired with a Stronglight 93 double crankset with 52/40T rings which is a big improvement over the original 45T inner ring the crankset came with. The 12 tooth difference is easily handled by the Simplex SLJ A522 front derailleur.

Likely the next change will be to replace the Mafac LS2 brake pads but as further changes occur, I will update the blog with an appropriate post.

 

 

A Bertin C 10 in London

 

Stuart Windsor of London, England may be a familiar name to you if you have been reading this blog for a while. Stuart is a professional photographer in London and the accompanying photos demonstrate this fact quite nicely. In August of 2016, he had completed a period correct restoration of a Bertin C 37 road racing bike which was featured here in September of that year and shared with other Bertin enthusiasts. It was a sensitive and complete restoration as can be seen in the original feature photograph from that previous post.

Drive side profile showing off the Stronglight 105bis

 

In that same period, Stuart had acquired another Bertin in shabby, almost derelict condition. It was dirty, faded, rusty with a few non-period components and generally showing as somewhat sad and hopeless as seen in the photo below.

Bertin C 10bis as acquired

 

Having just completed a full on restoration of the C 37, Stuart decided that a refurbishment of the C 10 was the way to go with replacement taking place only for the most outrageously deficient things like the rotted tires and tubes. Lubrication, cleaning, adjustment and lots and lots of Autosol polish were required to get to this.

 

The C 10bis after refurbishment

 

Stuart was kind enough to provide the pictures of the before and after which are shown below and they give a small idea of what must have been the tremendous amount of work necessary to bring the C 10 back to a usable and attractive state.

 

 

So, a vast change from grime to shine, from wreck to rehabilitated. Stuart’s C 10bis may not have the slick, like new, high gloss look of that blue C 37 but the scrapes and worn paint showing through the wax and Autosol speak of the intrinsic quality put into the bike by Cycles Bertin. Thanks for sharing, Stuart.

 

 

 

 

 

 

 

Bertin Finds in France

Finding old Bertin bicycles in France doesn’t seem like much of a stretch. Consider that Bertins can be found fairly readily in the UK, the US, New Zealand, Morocco and even, occasionally, here in Canada. So, no big deal to find them in their country of origin, one might think. However, this is not so easily done.  The bikes were distributed all over France so your geographical location would affect availability. So would the lack of co-operation from local sellers and those on leboncoin who can’t even be bothered answering foreigners like me.

However, if you lived in Normandy (geographically just down the road from Bertin’s home location) as an expatriate Briton, and made the rounds of yard sales, bicycle jumbles, boot sales and flea markets you just might have a good chance to snag some interesting bikes.

Which is exactly what Kevin, who buys and refurbishes classic French bikes, does in his spare time.  He had contacted me through the site regarding id confirmation for a couple of Bertins which he had found and purchased on speculation. We discussed the bikes and he was kind enough to allow me to publish their photos. The silver one was a C 35 in original livery and equipment which Kevin then cleaned and up-speced. The red C 37 has been extensively modified in terms of braze-on additions, a new fork and partial changes to its equipment group.

1970s Bertin C 35 (531 /Durifort) in original condition

1970s Bertin C 35 (531 /Durifort) in original condition

 

C 35 re-furbished with equipment upgrade

C 35 refurbished with equipment upgrade

 

red-bertin-fin-1

Modified Bertin C 37

 

My thanks to Kevin for rescuing and permitting the sharing of these Bertin survivors with us.

Mafac Brake Hood Restorations.

Mafac logoOn March 5th, 2015 I wrote a review of the full Mafac rubber lever hoods available from Jordi at Reciclone in Spain. At that time, Jordi did not make reproductions of the rubber-covered adjusters as he had no Shipping Boxadjuster in good enough condition to serve as a master from which to take a mold. Subsequently, after conversations with Jordi, I wrote, “Jordi is currently evaluating the practicality of making matching adjuster rubbers which would need to be added to the owners’ own adjuster body.”

To assist him, I mailed him a NOS rubber adjuster and a matching metal adjuster mechanism. After repeated attempts, he was finally able to come up with a satisfactory reproduction. He then emailed me and let me know that a complimentary set was on its way to me as a thank you for the use of  my original which he had mastered  for his mold. When the box arrived, it contained my original adjuster cover and mechanism plus a finished adjuster cover set and an example of the prototype moldings.

This whole project arose out of the difficulty involved in getting Mafac branded hood covers for restorations and, to a lesser extend, for everyday use. This was a particular problem for Jordi as Reciclone does bike restorations as well as sales of period spares and accessories for vintage bikes. Typically, the gum rubber hoods and adjusters dry in the sunlight, harden and begin to Adjuster # 4 modifiedcrack and then crumble. (See the red circled area in photo.) The left hand adjuster in the photo is Jordi’s reproduction. One solution is to simply delete the adjuster. Another is to switch to the period correct alternative of the knurled metal adjusters or the metal adjusters with rubber O rings (which also perish). However, if the bike had gum rubber adjusters on its Mafacs and a restoration is to be absolutely correct, then that is what must be replaced.

Should you find yourself in that position and go to the Reciclone page for hoods, you will not see an adjuster listed as an available product. The reason behind that is the difficulty involved in making the adjuster covers. The covers I received were cleanly molded in gum coloured  rubber. They were a perfect, tight fit on the metal adjusters and accepted the chrome steel ferrules to support the brake cable end with no problem.  Below is a large image to allow you to view the reproduction adjuster clearly.

 

Adjuster # 5 cropped

 

One of the problems with reproduction hoods and adjusters is matching the colours of the gum moldings. In the accompanying photo below, the hood on the left is a Reciclone reproduction and the hood on the right, with an adjuster, is a NOS Mafac part that was received exactly as shown when new. Typically, Mafac adjusters and hoods did not match due to batch variations in a large-scale production environment.

 

Comparison NOS and Repro

 

In a practical sense, this means that Jordi could not guarantee that your hoods and his adjusters would match harmoniously due to the colour variability of the batches of rubber for the moldings. As well, being small parts, the adjusters are very picky to make. So, as nice as they are, the adjusters will be special order items only, not regularly offered merchandise. You will need to contact Jordi (reciclone1@gmail.com) directly at Reciclone to discuss an order and I would recommend having the hoods molded at the same time to optimize your colour match. Regardless of which route you choose, good luck with your restoration.