Center Pull vs Side Pull
 

If I swap my old Shimano side pull brakes with a set of Dia Compe or Weinmann Center Pulls will it give me more tire clearance?

Tim

Maybe. Depends on the model of Shimano and the model of centerpull, but the tire to crown or bridge dimension will not change, one can change the rear slightly if the bike has horizontal dropouts and the wheel is adjusted back. Mafacs are more "open" then the Weinmann and Dia Compe which are almost identical model for model.

Depending on your brake pads and rim, you might need to put a spacer on your pads to bring them closer to the braking surface when using centerpulls.

More often then not, I've found that most pads of the traditional design will hit the rim at a considerably incorrect angle (and provide terrible braking power) if not equipped with a 1/8" spacer.

Take care,

-Kurt

This is the bike. http://69.16.211.161/showthread.php?t=197356 After looking real close, I can see that the rear brake bridge is the limiting factor. I was hoping to put taller tires on the Schwinn like the Waterford in the photo.

Tim

Related question:

I've got some old Dia-Compe cantilevers ('83) on my Centurion, and I was thinking of trying to swap out the 27" wheels for 26" or 700cs so I could add fenders and winter studded tires. Since one can't adjust pads up and down with cantilevers, is this impossible?

Use KoolStop pads. They come with versatile spacers and long bolts, making them easy to adapt to any brake caliper.

These are KoolStop "Continental" pads on my Weinmanns. The bike originally had 27" wheels and now has 700c wheels. You can see that the pads are adjusted close to the lower limit of the mounting slot, but they work just fine.

There were a couple of different models of the standard old Weinmann "999 Vainqueur" center-pulls. The 610 had shorter reach arms (49-61mm) and the 750 had longer arms (57-75mm) - Those are the measurements from the middle of the central pivot bolt to the centers of the brake pads. Dia-Compes are basically identical. Perhaps that will help you calculate where the pads will hit your rims.

Remember, 700c rims are smaller than 27" rims. If you are using 700c rims, the brake pads will need to reach down 4mm lower than they would for a 27" rim. This also means you will "gain" 4mm of potential tire height when using a 700c wheel in the same frame, so it may help you with fender clearance... but just a tiny bit.

There was one problem people have had when fitting older Weinmann brake pads. One style was cut at an angle for use with rims with sloping sides - typically 1970s 27" chrome rims or smaller BMX rims had a slanted braking surface. There were also pads which were cut with a normal flat edge, and these will fit most moderate width flat sided rims. Dia-Compe still made the slant-cut pads (as of 2005) which were designated their "#76" style.

Weinmann actually still made their last flat-cut pads until just a few years ago. They were known as the "WX" pads. I believe they simply let their patent go on these, and subsequently a Taiwan company called Jagwire began producing their own identical copies of these which they call their "X-caliper" pads. Nothing fancy, but they fit perfectly and seem to work well. I've also seen "similar looking" pads made by another budget company (possibly "Pyramid"?) recently. But these are smaller overall and are really to be avoided. The better stuff measure around 40 x 14mm (around the metal holders) and will reach down around 18mm measuring from inside the caliper arm to the braking surface of the pad.

As for braking efficiency; I believe you will get more mechanical assist by using aero-style levers. I haven't had any problem stopping one of my Weinmann equipped commuter bikes in the crappiest of snow/rain weather conditions even using cheap-o pads. However, as John E suggested, the Kool Stop "Continental" pads with their grippy red compound are really superior to anything else.

Have you thought about V-brakes? VERY adjustable, and fit on canti bosses (mostly, anyway). Might need new levers, though, depending on who you believe.
Top

Excellent information, I am thinking seriously about trying a 650B conversion on that bike. It would probably need some long pull brakes. The 999 are plentiful on ebay. the 610 less so. I can't ever recall seeing any of the 750 though. Did DiaCompe make an equivalent version?

Tim

If you mean an equivalent of the longer-reach 750 version, not only did they, they still do. You can get them from Rivendell. Check out Riv's website. I have a set, and they are a good option for old frames that have what was then considered long reach, which be today's standards is super-duper long reach for which decent sidepulls haven't been made in decades (Universal 51's would do it, but those are ancient and not the easiest things in the world to find) - just be sure to replace the pads with Matthausers or KoolStops if you intend to use the brakes for more than just decoration. The original pads just don't get it done, stopping power-wise. One :eek: episode with the original pads was one too many for my taste.

You will also have to have either brake levers or cable hangers with built-in "quick release" devices because the Dia-Compes (like Weinmanns and unlike Mafacs, which may also work) have no way built into the caliper unit itself to widen the calipers for removing the wheel. Riv has a couple of possible brake lever options for that too. One is a Dia-Compe standard lever (i.e., non-aero, cable-out-the-top) and the other is a Campy Ergo copy, except without the brifter gear-shifting capability. Shimano and Dia-Compe aero levers I have owned or seen do not have quick releases built in, so they are likely not an option for you, unless there is one or more models out there I haven't seen. As for cable hangers with quick releases, ask your LBS - odds are they have some knocking about.

BTW, Universal 61's would likely also work (but double check the reach measurements) and also show up on eBay reasonably often. (The 61's are center-pulls, the 51's mentioned above are sidepulls.) I am almost, but not quite, positive that all of the above info concerning lack of quick releases on the calipers themselves applies to the Universals, too. If I'm wrong on that, or anything else, I'm sure somebody will correct me.;)

Yeah, you're right. It was always a real pain to try to jigggle the straddle cable ends out of the caliper arms. By at least as early as 1970, Weinmann had offered cable hangers/stops with (optional) quick release devices attached, and Universal quickly did the same for their Model 61... but, they were both rather bulky extensions and difficult to use for the rear wheel - especially if you had a small bike frame, since it did not allow much room between the hanger and the straddle wire yoke. And, forget about it if you had a Raleigh with a brazed-on cable-stop arch!

Weinmann also offered some models of their levers with an integrated QR. This was a simple "push-in" tab, inserted just above the lever arms. Not as nice as or effective as what Dia-Compe had came up with on their levers by the mid-1970s, but it helped.

Universal's "Super 67" (pre-Campy) side-pulls had a really funky QR lever - sort of a long parallel bar - incorporated into the calipers. Funny how long it took the Italians to come up with something simple which actually worked... and, basically the same as what ALL side-pulls STILL use. [Thank You, Tulio!].

I guess the decades long fondness of the French for cyclo-touring really gave Mafac an edge when it came to realizing an utterly simple way disengage their straddle cables on both their cantilevers and centerpulls calipers... not to mention the simple tilt feature for aligning the pads with the rims - just like on all MTB brakes today.

Gee, ain't simple technological advances grand?

Sorry to digress (again), but since I just mentioned it in my last posting... Check out these swell auction photos showing Universal's early sidepull QR mechanism. ~ Really not something I'd want on my calipers, but...

http://cgi.ebay.com/ws/eBayISAPI.dll...ADME:B:SS:US:1

Only the Italians could complicate as simple a device as that. No wonder my wife says "your family makes everything so complicated." LOL :D

Tim

Well, Not just the Italians... Weinmann was "stubbornly" Swiss. The seemed determined to come up with their own unique solutions - in spite of what other companies (ie: Campagnolo) had already perfected. In their "605" calipers from the late '70s the made their first attempt at a QR for their sidepulls - here's an example of them:

http://cgi.ebay.com/NOS-WEINMANN-605...QQcmdZViewItem

Although this was nearly a decade after Campy's flawlessly designed brakes, Weinmann tried to build their own "better mousetrap". What they came up with on these (not real clear in the photos) was a steel cage clamped around the "upper" caliper arm which, when released, dropped the threaded cable adjuster AND the threaded sleeve which it hung inside. Worked fine, but why do it this way? ~ Otherwise, these are great calipers. Note those clever, smooth operating, white nylon bushings. These fitted inside the bores for the center pivot bolts - and simultaneously isolated the caliper arms from each other, minimizing any friction between them, as well.


They eventually just made fine quality copies of the Campy calipers which they called the "Carrera" model... But, not until the '80s did they re-locate the QR on those to the customary lower caliper arm!

[As you can tell, I'm fascinated with the evolution of all the bike technology which we take for granted today.]

Another excellent answer. I wish there was some main bike technology source available. I know, this is it. Not really but it is close.

Tim

If anyone is considering an Aero lever conversion on one of their bikes you should check out the thread I just posted under "Best Aero Brake Levers?"... a real bargain clearance deal I came across when salvaging (again) for another of my own current projects.

If anyone is considering an Aero lever conversion on one of their bikes you should check out the thread I just posted under "Best Aero Brake Levers?"... a real bargain clearance deal I came across when salvaging (again) for another of my own current projects.