^ Take a look at that picture and tell me if anything is missing. Never worked on U-brakes before. I believe this part is missing on one side:



When i mounted them on the bosses, the side missing it did not have any spring tension. when in my hand I can move the spring by sticking a hex key in there while with the other side I cannot, leading me to believe I need that part.

With a little research, I think I can replace that with one of these: Shimano Shark Tooth U Brake Accessory | eBay or am I way off base?

Thanks for any help! r e d d i t and the vintage MTB facebook group was no help

:/

Would ask on on teh classic forums, or on Retrobike, as this is a really old/unusual (as in short life no longer used part)

Thinking it would probably be easiest to go on ebay an just buy a new one, as yours looks to have other issues than just the missing part

As far as the Shimano Shark Tooth goes, it's a device to prevent the chain from jamming between the brake arm and the chainstay (chain suck). I don't think it will have any effect on the spring tension problem. It's been awhile since I've worked with U-brakes, but I do remember them being a pain in general. My wife's bike came with one and I replaced it with a WTB roller cam and never looked back.

Yeah :/ I know the easiest thing would be to scrap it and buy a another one, but I was really trying to get this one going as I was trying to get the bike rolling with minimal money(though new stuff where it counts like housing/cables and chain)

Didn't think of CV or Retrobike, thanks.

I assumed it could replace that cap looking at this:





I had thought of rollercams, but didn't think I'd find any on ebay, checking now I see there are a few. If I did replace the u-brake with a rollercam, would it work on my under-the-chainstay mounts?

Yeah, I know what you're getting at but, without having the brake in my hand, I just don't know if it would solve the spring issue. As far as mounting a roller cam under the stays, absolutely! That's where my wife's resides.

I'd just replace it with one of these:
https://www.amazon.com/Tektro-FX570-R...ywords=U+brake

read the instructions carefully, and follow them. You can find them on Tektro's website, if you want to read them before purchase. These brakes work well and are inexpensive.

That looks like a great solution!

I was under the impression that bmx u-brakes would not work, but now I can't find anything to back that up.

I have put a Tektro FX570 on a GT MTB, and on a BMX - I did not see any difference in the mounting or reach.

I agree, especially because that Exage unit looks like plastic coated steel...

I don't even know why I thought that. I don't see any reason they wouldn't work.

That doesn't affect the function of them one bit, if I had a shark tooth or that cap they would work just fine

U brakes Seem to still be offered in the BMX world to just get a whole new caliper .

rather than seek out a part that is 20+ years past its making ..

Oh, I didn't notice your avatar before.

Yes, you are right, they are perfectly good brakes; by all means do what you can to salvage them...

What does my avatar have to do with anything?