Hello Everyone! I recently picked up a 1985 Trek 410 have been using it as way to test the waters of steel and C/V bikes. Unfortunately the return springs on the Dia Compe G500 brake calipers are worn out. As such, I am looking for suitable replacements, but it turns out that there isn't a big selection of nutted brakes available. I have had my eye on the nutted version of the Tektro R539. Do you have any other suggestions? I don't care much about keeping the bike original as some previous owner converted the bike to 700C. Thanks!

I'm in the same process - the only other option that I have found readily available is the Tektro R559 - although I am having a bit of a hard time finding either in the nutted variants.

If you have no concerns for period-correct appearances, just do it. Those 539s will give you a HUGE improvement in braking performance, to the point where you will want to be careful until used to how powerful they are compared with the old DC sidepulls.

You could put up a WTB in the C&V for sale forum. Someone has brakes that will work that they would be happy to sell.

I have a set of G500 brakes in nice condition I'm willing to part with. Feel free to PM me if you're interested.

I am interested, but I can't DM you until I have 10 posts. I will work on that today and get with you tomorrow. Thank you!!

How do springs wear out?
Try wd 40 on the pivots and cables. Free them up and then add oil.

There is no way to say if this will be true or not.
What levers does the op have?
How strong is the o.p?
What size hands?

fair points all, but experience with these has taught me that just a straight swap of the calipers - without changing anything else of the existing setup - will result in significantly stronger braking.

That is true for you but you can't say it will be true for the o.p.

Fully agree! I’d take the brakes completely apart then clean and polish (especially in the area of the pivot points). When reassembling and mounting, be aware that there is a fine line between too tight and too loose .

agree that 9 times out of 10 it's gummed up pivoting that is the cause. However I have found that the springs on cheaper calipers - especially abused ones - sometimes take on a deformation/bend where they pass through the central bolt, and thus weaken in their action.

I'm no metallurgist, but I have seen some improvement by gently straightening the spring's center section back to its original shape while getting it good and hot over a flame, then quenching it into water. This has worked to "rescue" crappy calipers several times, but who knows, i might be shortening the springs' life considerably.

Well if the spring is goosed and you are getting a bit more out of it by doing that I don't see the harm. What's the worst that can happen?

suspect the heat/quench may stiffen the metal but make it more brittle, so maybe spring snaps sooner? certainly not catastrophic when it fails, so it's a hack i've been happy with.