scozim 

I'm finally getting some time to categorize my myriad of parts and have this long reach mystery Dia Compe brake caliper. It looks like the spring might be sprung but the caliper itself is in pretty good shape and doesn't look like it was used much.

The first photo shows how it sits normally and then moving it to the position my other calipers are at. Could it be it just needs a cable to hold the tension - this caliper is quite large.

Amani576

Better it over spring than under spring, I say. You won't have to worry about it not releasing.
-Gene-

cudak888 

That is entirely correct and normal. You ought to see a Weinmann 1080 sidepull.

-Kurt

cinco

Looks fine to me and you appear to still have plenty of spring tension. I think what's making it appear so different is, in fact, the size. Y'see how the outer arm hits the inner arm's pad area when it's relaxed? Well look at your second pic and imagine where the inner arm's pad area would be on a human-sized brake - much closer and at rest the brake would look more normal. By the way, that's gotta be the longest reach brake I've ever seen.

scozim 

It's about as long as I've seen also - wish I could figure out what model it is. I didn't see anything that looked close on Velobase.

cudak888 

Weinmann 1080. Look for the rear brake on a stock Raleigh Twenty. Massive reach.

-Kurt

scozim 

That does look like it. I know Dia Compe and Weinmann 610 center pulls were essentially the same brake. Probably not too far a reach then to surmise Dia Compe also sold the Weinmann 1080 and just stamped it with their name.