$pecial

I have a Specialized Sirrus from 1991 that I want to upgrade the brakes. Long story short, I have the original pads and the brakes were horribly noisy since brand new. I road the bike for a few years and dealt with it and then stopped biking for about 11 years, due to history of accidents, and the fact that i never got excited about this bike. Well I dusted it off this summer and tuned it up found out the rear hub wasn't put together tightly, the BB was not put together completely and put new tape on and now I'm loving it. Although it is to big (one other reason i disliked it) and now I'm probably selling it. I had two different mechanics attempt to adjust the brakes to remove the noise, but we've concluded it may just be crappy pads. well, i found a set of calipers from a 2010 Trek 1.5 for the same price as new pads. They are Promax

My current Dia Compe calipers

the new dual pivot calipers


My question is about the mounting stem. The front stem of the new one is longer than i need since the trek has a nice thick carbon fork. I assume i could simply replace it with a similar, shorter bolt. The main question is about disassembly, Is it ok to remove that bolt on the pivot arm blocking the stem (I also have to remove the small adjustment screw that holds the arms together)? Then, once that is removed is there any concern with the spring when i go to replace the mounting stem?

tomio

You can use spacers to make it work.

Homebrew01

I would try to find a solution that does not involve replacing the bolt. Use spacers as suggested, or grind down the bolt a bit, or use a nut & washer instead of the recessed nut.

sonatageek

Why not just move the pads from the Promax over to the DiaCompe calipers and be done with it? Easy and it sounds like you just want to quiet the brakes down so the noise does not kill the sale.

dfischer1

Just use new pads that are toe-ed in correctly.

Brakes are brakes. No need to replace the calipers.

$pecial

actually, I didn't realize until tonight that the pads were compatible with the older style caliper.

wouldn't there be any advantage to the dual pivot caliper? Not enough to be worth it?

dedhed

Buy a die and thread the mounting bolt further down if needed, cut it off to the length you need. The new dual pivot calipers will work much better than the old brakes, stopping power wise. Those edge should have aero levers and lever pull "shouldn't" be a problem. IMO Usually a good upgrade on an older road bike. I have a number of 25 mph bikes with 15 mph brakes, even with Kool Stops.

$pecial

Duh, didn't even think of that. I even have a die already. thank you

Kimmo 

Definitely, but there's no point upgrading the rear.

fietsbob

note: top range Campag brakes are dual pivot only in the front.. single pivot is fine.

Fit new kool stop pads ,their salmon colored compound is my favorite .
Long front mounting bolt is for nut fixing , a star washer between the brake and frame keeps the brake centered solidly.

dedhed

He's already got the new calipers, might as well install them instead of having 2 sets of mismatched stuff.

Kimmo 

I'd rather have brands mismatched and the design of my components matched to their job than the reverse.

Sounds to me like you're saying, might as well throw useless metal on my bike to satisfy my OCD. The single-pivot front can be used for a rear and the dual-pivot rear can be used for a front, with a bit of stuffing about. Proper braking for two bikes.

The rear brakes are likely to match the rest of the bike's gruppo anyway.

I definitely wouldn't bother with the star washer; it doesn't take much tension on the mounting bolt to hold the brake in place without one.

Retro Grouch 

That's what I think too.

You have a 19 year old run-o-the-mill road bike that doesn't fit you. Frankly, it's not going to be very much fun to ride because it doesn't fit and it isn't going to bring very much when you sell it. It's a mistake to put very much time or effort into this bike. Just stick a new set of pads on your brakes to kill the squeal.

$pecial

Well I finally got some time to play with the brakes last night. I totally over-reacted about the front brake stem being too long. At the time i only eyed it up and it seemed too long, took things apart and the stem was the exact same length. I am so glad I wasted the time exchanging both calipers. Not only did I learn a lot, I enjoyed the time spent with my bike. I certainly could have just replaced the pads, but that wouldn't take very long and I like to tinker and tweak.

The modern calipers look nicer to me (only affects me, i know) but holy cow do they perform better too. I admit the dual pivot is overkill on the rear, however the matching parts (since it's not a downgrade) matters to me. Plus I imagine when selling this run-o-the-mill bicycle the matching parts (along with the included original parts) may sell better than a mismatched setup (even if poorly designed). I had both brake assemblies swapped in about 30 minutes, now to go read up on adjusting dual pivot brakes.

The more work I do on this bike the more I want to just keep it. BTW, the noise is gone and as an added bonus the person I purchased them from replaced the front pads with kool stop pads.

brockd15 

Good move changing both. Only upgrading the front would make no sense at all when you have the rear dual-pivot available.

And I'd take a run-o-the-mill Specialized Sirrus any day of the week.

$pecial

Thanks Brock, I like the bike too.

fietsbob

Kool Stop Salmon compound brake shoes alone are a brake upgrade, I fit them on my 90's Brompton's single pivot CLB calipers .

they help a lot . I live in a steep hilly often wet town, and It's become my bike of choice..

For heavier loads ,I have a Trekking bike, with hydraulic rim brakes .. already good braking got better still
with red/salmon compound brake shoes.

brockd15 

Hard to tell from the pictures, but are the tires rubbing the calipers?

$pecial

no they are not, it's the angle of the photo. They are however extremely close (about 2.5mm clearance) and even the original brakes were very close maybe 4mm clearance. I was actually a little disappointed at first when i put the new brakes on (without the cables attached) because the rear wheel wouldn't turn, then i gave the caliper a squeeze and all was good.

My next bike will definitely have Kool stop Salmon, I've heard only wonderful things about them and I have a lot of mass to stop these days (less each ride though, fortunately)