Bicycle Mechanics - Help choosing brakes?

I'm converting a Univega Viva Sport to 700cc and the old Dia Compe brake pads rub on the tires (35s). I lowered the pads as much as possible but there's still rubbing on the front tire. I got some Campy Veloce side pull brakes to replace the Dia Compes with but the mounting bolt is too short. :-( Is there a different brake I should be looking for or an adapter for the Campys.

Old style nuts securing the brake or a recessed allen key sleeve? I looked at improving the brakes on my 70s style roadie myself and met the same issue. Bolts too short because they are designed to work with a recessed sleeve whic requires a larger diameter hole on one side. I did find that you can fit a front caliperr to the back even with the mismatch as the bt is just long enough.

your old calibers, how much metal is there below the slots that the pads adjust in? on my son's 27->700c conversion (very early Trek TX series), I was able to use a small rat tail file to extend the slots in the brake arms so the pads would go 2mm or so lower, and that was just enough that they nicely rode on the rims, there was still plenty of metal left. I also used a minimal washer between the pad and the brake arm, as that meant the arm was at a lower angle, which reached just a bit farther down. instead of spherical washers for adjusting the toe-in, we reverted to the old fashion crescent wrench and twist the arm slightly method. I also trimmed a bevel on the top edge of the pad.

I think the Veloce are also too short reach, for what, I have to guess, since it is not stated
Nor can I see..
is another 700c wheel in a 27" frame (622 is less than 630)..
you need a longer reach brake, or just buy a different Frame for the wheel size you want.

Tektro now is a source of various reach brake calipers .. External nut type most likely, required.

Sounds like you are in too far to go back, but for others considering the move, sometimes the problems going from 27" to 700c outweigh the benefits. There are a lot fewer choices in tires and prebuilt wheels for 27", but there are still some out there. There are additional choices in wheels if you're willing to build them or have them built. If it's just a matter of keeping an older bike on the road it might make sense to stick with 27". That's what I did a couple years back when the rear hub on my 1980's sport touring bike went bad.

You need what are now known as "long reach" brakes. These typically have an adjustment range from 47-57 mm compared to "short reach" with a range of 37-47 mm. Shimano and Tektro both make this style brake and Tektro offers them in the older nutted type also.

I'd like to keep all of the original parts on this bike as clean and original as possible because when I got it everything was pretty much immaculate, in case I decide to sell it later I can put everything thing back original. So, filing down the original brakes is definitely not a route I am going to take. Thanks for the suggestion, though.

I do have the funds to have a proper set of brakes so any new suggestions is gladly welcome. Below are some photos of the frame and what I have to work with.

Front:
http://farm9.staticflickr.com/8470/8383537715_c509ea3767_z.jpg

http://farm9.staticflickr.com/8469/8384622116_9078f32906_z.jpg

Rear:
http://farm9.staticflickr.com/8502/8383538873_5703690da5_z.jpg



http://farm9.staticflickr.com/8075/8383539327_130eab81a1_z.jpg

I don't want to get the wrong brakes again, though...

+1 on the Tektro long reach brakes, worked great on my 27" to 700c frame conversion.

Tektro's R730 (BR7308) Long Reach Road Calipers (47-57mm) work great on my track bike framed build. However, I (of course) have the pads set nearly as high in the arms as they'll go (which is no big surprise with the 700c wheels).

These brake calipers offer strong, yet predictable, stopping power and are very well made imo. I'm a huge fan of the Avid BB5 F disk on my wifes hybridized mtb bike, but these Tektros are really very good for the price imo.

Ok, so I am looking at either getting the R737 or R539

http://www.tektro.com/_english/01_products/01_prodetail.php?pid=64&sortname=Brake&sort=1&fid=2

http://www.tektro.com/_english/01_products/01_prodetail.php?pid=65&sortname=Brake&sort=1&fid=2

Regardless, what I need is a 47-57mm reach caliper with old style exposed nut mounting?

Regardless, what I need is a 47-57mm reach caliper with old style exposed nut mounting?
If you want to keep the frame exactly original, yes, you need a pair of nutted brakes. If you are willing to compromise you can use a 5/16" drill bit (aka 8 mm) to enlarge the existing hole in the rear (only the rear) face of the fork crown to accept a recessed nut and use "modern" style brake calipers. The problem is with the rear brake as you can't easily enlarge just the front of the brake bridge hole so you will need a second front brake to allow using a conventional nut there.

Yes, enlarging just the front of the brake bridge can be a problem. I was able to do this by using a short 8mm (5/16) drill bit (a "cast-off" from a bit I broke earlier) and doing it by "hand" with a pair of needle-nose vise grips. Took a little extra time and effort, but I ended up with nice proper sized hole nonetheless.

You can also use a Dremel tool with a 6-8mm grinding stone (the trick is to feed the Dremel stone shaft in from the front of the brake bridge followed by inserting and tightening the Dremel tool from the back side). You can then grind the front bridge hole out to the desired size. In some cases, there's enough room between the front of the bridge and the seat post to allow you to just grind the hole out to size while using the Dremel in a normal way without all the "threading the stone shaft through the bridge" stuff (a long shaft Dremel stone can help with this).

But hey, I fully understand your desire to leave the frame in its original form.

Yes, enlarging just the front of the brake bridge can be a problem. I was able to do this by using a short 8mm (5/16) drill bit (a "cast-off" from a bit I broke earlier) and doing it by "hand" with a pair of needle-nose vise grips. Took a little extra time and effort, but I ended up with nice proper sized hole nonetheless.

You can also use a Dremel tool with a 6-8mm grinding stone (the trick is to feed the Dremel stone shaft in from the front of the brake bridge followed by inserting and tightening the Dremel tool from the back side). You can then grind the front bridge hole out to the desired size. In some cases, there's enough room between the front of the bridge and the seat post to allow you to just grind the hole out to size while using the Dremel in a normal way without all the "threading the stone shaft through the bridge" stuff (a long shaft Dremel stone can help with this).

But hey, I fully understand your desire to leave the frame in its original form.
Great ideas. I've done the first method to enlarge the front of the brake bridge also using a short 5/16" bit and turning it a fraction of a turn at a time with a Vise Grip. Slow but it eventually works.

The tapered stone in the Dremel is new to me and sounds like a good approach.

If you have an older bike that you don't really want to put newer parts on, look for brakes made for 27" wheels, that have a lot of adjustment room. I just put some old Shimano Tourney calipers on my old Italian 10 speed, and it looks like it'll work out great. The only thing there is, you'll need to make sure you get the cablehangers, or cable stops, whatever you want to call them. BTW, Tourney calipers are exactly the same as early Dura-Ace, just labeled differently, so they're pretty good quality center-pulls. ;)