Bandera

When I went through the Chicago factory school for Schwinn Approved mechanic certification in the '70's we were shown the proper technique using the two 10mm Weinmann open/closed brake wrenches to reliably center Varsity brakes: No violence required.

That being said I have the choice on my town bike to use a variety of C&V calipers from my stock and go w/ Weinmann 610 center-pulls: simple, reliable and effective enough.
Brakes will only slow you down, I've never gotten obsessed w/ something that I use as little as possible.

-Bandera

HTupolev

Not just a matter of MA. The long distance from pivot to pad on single-pivot brakes results in lots of flex if the arms aren't made heavy and stiff (or very short, severely limiting clearance). Oftentimes the modulation is spongy and regressive as a result.

verktyg 

I've used an 8" x 3/4" brass drift for years to center side pulls that don't have adjusting flats. I place the end on top of the spring at the center pivot and give it a gentle tap or two. Works every time. I also recheck the tightness of the rear mounting nut before and after minor surgery. I've seen the nut loosen a little after the operation.

In the past year I've had the pleasure of overhauling Weinmann 605 brake calipers plus DiaCompe levers and DiaCompe 610 calipers. I wasn't aware of the differences in the springs but just about every thing else between the 2 brands interchange.

I took the suicide levers off of a set of DiaCompe levers and replaced the red pivot pins with Weinmann ones, also the nylon bushings. Those bushing wear quickly especially with the angular torque applied by the suicide levers. Replacing the bushings makes a big difference in the levers.

The later version DiaCompe center pulls came with decent pads that have a lot of stopping power. Again, I sand down the faces of all of my brake pads whether new or replacements or during servicing.

3M makes a product called Drywall Sanding Screen. It's inexpensive and you can get it at hardware and paint stores. Medium grit works well for sanding down the braking surfaces of pads.

I put a sheet of paper on a flat surface and put the screen on top of it (the paper makes it easy to collect and dispose of the dust). A few minutes per pad making sure the faces are square to the holders and it's done. taking 1mm of old hard pad face takes a little longer.


Screen Cloth looks like this:



I have Weinmann 999 brakes on my 1965 Tigra. The caliper arms are beefier than on later 610/750 brakes.




Old Weinmann 500 style side pulls on a 1960 Schwinn Paramount




Notice both style brakes have short 3 Dot brake pads.

verktyg

cudak888 

This is where the Kool-Stop compound comes into play. The extra grip afforded by the compound compensates for the lack of rigidity of the Weinmann arms - making a "meh" brakeset into one that performs well.

Of course, some (myself included) may not accept flexy brake arms on their machines, so this is where it boils down to personal preference.

I'm surprised nobody has mentioned rim width in regards to centerpulls either. The Weinmann 999/610/750 and the Dia-Compe copies are made for wide rims. The brake arms are placed well apart from each other; enough so that factory Weinmann pads and similar copies are usually not wide enough to be used in conjunction with many popular road rims of the era (Super Champions, Rigida AL1320's, etc).

However - with that said - this does not seem to prevent many people (or mechanics) from trying to use them improperly with narrow rims and C&V-style brake pads. The gap results in pads that get swung upwards at a 10 degree angle to meet the rim surface as the caliper arms are overextended.

I don't consider such a setup correct, nor a valid metric to critique the performance of the 999/610/750 upon. It is possible to compensate by running a modern pad with enough thread to allow for some inboard shimming, but most C&V pads don't have enough threads to allow someone to put a washer between the pad and the caliper on the inside.

-Kurt

ThermionicScott 

How wide are we talking? I'm running 750's with Kool-Stop Continentals on 24mm rims, and now I'm curious whether I'm over or under the intended use.

Salamandrine 

FWIW I've been riding the Gran Compe 610 reissues with Velocity A23 rims for the last several years, and they work just fine. As one might guess, A23 rims are 23mm wide. That's basically the same as old Super champ 58, and Weinmann concaves, IIRC.

Rigida 1320 were more like 19mm I think. Didn't stop Motobecane (et al) from spec'ing them with Weinmanns on many different bikes BITD. Didn't 1320 have slightly angled sides? That probably helped a bit.