squirtdad

I think gugie next project should be a complete frme built from scratch, bonus points for setting up for the new Nirvex derailler

Andy_K 

Yeah, the blood curdling scream is definitely a safety feature. You know how Harley riders say "Loud pipes save lives" (which, as an aside, is kind of the motorcycle equivalent of "I read it for the articles") -- for bicycles, loud brakes serve the same purpose but in a less aurally pleasing way.

Drillium Dude

I once owned a Sparrow (build by the late Dennis Sparrow in Missoula, MT) which featured offset cable guides. In the case of the Casati, the inspiration came from noting a couple advantages in adopting that approach.

The offset guide is a practical feature for two reasons: (1) it allows for a smoother curve of the housing at the bar-to-first-guide transition, and (2), it makes allowance for the housing to exit the rearmost guide without rubbing against either the top eye of the chainstay or the seatpost. This solution alleviates both braking performance loss and aesthetic-ruining paint loss due to vibrations/rubbing.

DD

panzerwagon 

I would add to that list: (3) the elimination of the moisture cradles (a.k.a top-tube guides) that too often end up rusty.

79pmooney

You seen me say this before re: the RACER calipers. Fun in Boston traffic. When a driver pulled a fast one on me, I'd hit that front extra hard (whether or not I needed to slow). Then I'd point at the driver. Every head on the block would swivel to me. Their eyes would follow my point. At roughly the same time, the driver, awakened by the Mafac screech, looks up. And guess what? Every eye is on him! Driver slinks off like a scolded cat.

The old Mafac pads could nearly always be set up to be sorta tolerable for most stops and simply scream when needed. The modern KoolStops don't work nearly so well. Better pads but those old Mafacs, when withing a few years of new, were actually superior pads. The Mafac pads on my Mooney's cantis gave me one finger braking down Santa Cruz's Alba Road in a January winter storm with inch deep rivers running across it. (Well, after two miles, my very wet and very cold hands had to go to two fingers.)

Mafac RAIDS just got mentioned, Never had either them or Competitions but just got a pair of rather nice Competitions. Might have to build a bike around them. Or hoard them until needed. I bought Cyclone calipers a while ago for no reason at all. Just beautiful units. Shortest reach I have ever seen. Last summer. put the Pro Miyata together. Closest brake to rim I have ever seen! Pulled out my box of calipers. There it was! Pads pushed all the way up fit just perfect. Wanted to set the bike up Superbe but I had the Cyclone D stuff. So its a full Cyclone gruppo. Well the RD is a much older unit. Tired spring and struggled to get the small cog. So - I wrapped it with blue bungie that matches the paint nicely. Sailor's whip behind the parallelogram. Shifts like new!

79pmooney

I'll have to sit on that thought. I love full length center of top tube rear brake runs. Top my eyes, that simply looks right. And have the reduced braking power from all that housing compression. Better panic stops. And while Mafacs are being discussed, my two winter/rain/city bikes have one pair of RACERS split between them as front brakes and Weinmann calipers off a Schwinn like-wise split up as rear brakes. Mafac power in front. Full length housing and stiffer calipers add up to less power and same feel in back. Minor pain to work on but wonderful to ride. And panic stops are fun! Now if I could only incorporate those sound effects.

Drillium Dude

Try as I might, I can't visualize your hack - perhaps you might share pic or two?

DD

ehcoplex 

Drivers in the US, overall, are awful, but Boston has always seemed to be in a league of it's own....! (no doubt the city's layout and traffic 'engineering' greatly contribute, but still......)

Drillium Dude

You're probably referring to the Casati's original internal brake cable guides, correct?

If so, I'm in complete agreement, as I find they do have the tendency to take in moisture (generally, for me it's sweat - I don't ride in the wet). Additionally, the braking never felt as solid/direct with internal guides; the feel is much better with a full-length housing. That's why the only frame I never had issues with - which had internal guides - was a Tommasini I once owned. That one had an internal tube the length of the top tube, and the guide entries (and internal tube diameter) allowed a vintage-diameter cable housing to enter and exit with no problem.

Gratuitous pic of the built-up bike (in Diego Garcia wind-cheating mode):



Of course, the potential for sweat to seep in was still present in the design - but at least my braking feel didn't suffer.

DD

nlerner

I don't know when @79pmooney last lived or rode in Boston, but in the 30+ years that I've lived and regularly bike commuted here, the city has increased bicycle infrastructure by orders of magnitude. Sure, drivers are generally crappy, but that's been true everywhere I've lived and biked.

52telecaster

My town isn't great but it has improved too. I think younger people in city governments help. I still like my screaming mafac though.

rccardr 

If you’ve ever heard a rabbit scream, you know what I mean.
No more MAFAC’s for me.

steelbikeguy

did MAFAC ever have a mascot (like T.A.'s Fifi)?
If not, I think you just found the perfect one.




Steve in Peoria

AngryScientist 

Tech question for gugie if he wouldnt mind:

I assume these mods are done via silver brazing? I've read conflicting information on the googles, what's the melting temp of silver rod? What's your torch set-up? I have an oxy/acetylene rig, but was wondering if it's possible to silver braze with a simple map gas torch? I'd like to do a little fooling around in the shop myself. Thanks in advance....

gugie 

All of my small bit additions are silver brazed. An important exception would be cantilever/centepull brazed on posts, where I like the additional strength.

Silver will braze with MAPP gas, I believe that's what @lonesomesteve uses. Since you have both types, try them both out and see what you like best. Oxy/acetylene needs to be turned down to a very small flame when doing silver on small bits for better control.

AngryScientist 

Thanks! So I have to ask, what are you using for the brake posts? tig? I'm struggling to think of what other options would be out there?

gugie 

I use brass (bronze) on posts.

You'll need the your oxy/acetylene torch if you go the brass route.

79pmooney

I grew up just outside Boston and lived in Cambridge 1977-78 as a racer. The first bike paths were going in as I raced. Never rode them but took in a few bikes that had encountered potholes and other obstacles on the paths. The roads meant taking a lane if you dared or riding within the door swing. Good thing is that drivers did look because cars were regularly within the door swing. Not looking got very expensive very fast. My two door encounters were in the suburbs and on the west coast.

52telecaster

When I was a teenager we would take the lane and occasionally get told to get off the street by the cops. It was a beautiful time. My town ain't perfect but it's way better 40 years later.

bikingshearer 

I once came very close to being doored on Mass Ave in Arlington in the mid-80s. As you describe, between the car lanes and the parked cars, there was virtually no room for bikes. Drivers acted as if cyclists were wearing invisibility cloaks. I got very good at looking in rear windows or rear-view mirrors to see if anyone was in the driver's seat. One day, I'm riding along in the omnipresent traffic with me plastered up against the parked cars. As I got up to the rear quarter panel of one car, the door started to open. I am blessed/cursed with a very loud voice, and I used it to tell the driver to cease and desist from further door opening right now. It turned out to be a 70 or so year old man and l scared the beejeezus out of him. I think he got a whiplash from turning his head so fast and he looked like he was about to have a heart attack from fright. But he stopped opening the door, which was the desired outcome.

Yes, Boston area drivers are terrible, or at least were in the mid-1980s. They were quite consistent in some ways, however, such as: (1) if you have a choice of two lanes, take the middle one; (2) lines painted on the road are purely for decoration and can be ignored at will; (3) never use your turn signal as it only gives the other guy an unfair advantage; and (4) if you are going to do something stupid, do it as sloooooooowly as possible in order to inconvenience as many people as possible (except on Storrow Drive, where no cyclists dare go - the normal flow of traffic there forces you drive fast enough so that the laws of physics make it impossible to stay in your lane). The infrastructure does not help the situation, to talk of a Boston road "system" is to stretch the meaning of the word beyond all recognition. And don't get me started on the rotaries ("traffic circles" everywhere else in the USA), which were scientifically designed to maim and kill. Between the drivers and the infrastructure, driving/riding in Boston made driving/riding in the Bay Area, including San Francisco, feel like a walk in the park by comparison. I enjoyed my time in the Boston area, but there are two things I do not miss: the weather (snow in a big city? No, thank you.) and the drivers.

bulgie 

An oxy/acetylene torch can also be used with LP/propane or MAP gas — sometimes. You may need a different regulator and maybe hoses, since some of the stuff for acetylene won't work with petroleum-based gasses like propane or MAP. The petro gases attack the kind of rubber the acetylene-only hoses and regulators use. Some regs and hoses work fine with both/either, and that makes switching to propane super easy if you have those. Like if you'd rather get your fuel gas at the Safeway or Ace Hardware down the street, rather than have to go to the local welding supply, not so local for a lot of people.

Which regs and hoses, which torches and tips to use, is getting too off-topic for here. But I can link you to a few other sources if interested.

By the way, maybe it's quibbling but MAPP hasn't been produced in the USA since 2008. What you can get now are "MAPP substitutes" like MAP-Pro (the "Pro" is for Propane, which it contains). Just call it MAP for short (one "P")
MAP does burn a little hotter than propane, but not as hot as the old MAPP, which was not as hot as acetylene. But the main reason (by far) that a "MAP torch" is not as hot as O/A (oxyacetylene) is that what we call a MAP torch almost always burns the MAP with ambient air, not supplied oxygen. Giving the flame pure O2 really takes it to the next level, so even a "cooler" fuel like propane, with O2, is much hotter than MAP or MAPP burning with only air.

I say this just to point out that acetylene is not necessary for brass* brazing. Propane with O2 is plenty hot enough. I'm pretty sure it's always been used in more medium-to-large scale bike manufacturing than acetylene ever was. Especially if you include the gas previously made from coal, called "town gas" in England.
(*I say brass here though many others say bronze. We're talking about the same thing. Some people say I am flat wrong, but I have my reasons. Let's not argue, just subsititue bronze in your head whenever I say brass.)

So what you need for brass is oxygen. Which fuel gas to use is of secondary importance. They all work, if you give 'em the O2.

I still have both acetylene and propane. I will probably not refill my acetylene bottle when it runs out, because propane works for everything I do. Neither propane nor MAP (or any petroleum-based fuel) can be used for gas-welding of steel, you need acetylene for that, but I never need to gas-weld steel. The ease of picking up a propane bottle practically anywhere sure beats schlepping my heavy acetylene bottle to a distant LWS (local welding shop). Oh and I got an oxygen concentrator, so I won't need to get the oxy bottle refilled either. It's an old medical device, too clapped-out to use on human patients, but it makes my propane burn like crazy. It pulls near-pure O2 out of thin air, using household AC electric power, which is a kind of magic.

I don't hate the welding store, but I'll be glad to not have to go there anymore.

Mark B

JohnDThompson 

When Trek moved out of the "old red barn" in downtown Waterloo to the "new" factory on the edge of town, oxyacetylene at individual work stations was replaced by oxy-propane delivered through a manifold system. Literally tens of thousands of brass-brazed frames came out of that system.

AngryScientist 

Mark, I dont want to derail this thread, but just wanted to say thank you for all of this and gugie too for the info.

gugie 

I'd really like to switch to Propane/Oxygen and get a refurb oxygen concentrator setup like @bulgie has someday for the reasons he states above. When I do I'll be sure to contact Mark for hose/regulator/tip recommmendations.

I also feel the potential scorn of the bronze police when I use the term brass brazing. Even though it's technically incorrect, common usage and decades of using the term and the fact that everyone knows what you're talking about when you say brass brazing reminds me of the grade school teacher that told me ain't isn't a word. Y'all ain't a word either, but it's extremely useful, and no one confuses the meaning.

Velo Mule

Doug Fattic is also uses a propane O2 set-up. I've used MAP gas to do braze-on cable guides. I'm keeping an eye out for a O2 concentrator.

There are several discussions of propane-O2 on the framebuilders forum @AngryScientist . Here is one to start out with: Propane Torch Setup