BaseGuy

I've got this great, garage-sale Cannondale from 1987. I'm in the process of replacing the brake levers and cables, but would like to replace the old DiaCompe calipers, too, because they are tough to adjust and keep centered.

I've done some searching and reading here, but can't figure out what my options are. Does anybody make a direct, bolt-on replacement for these old calipers?

pcb 

Kinda hard to tell without photos or a description of the calipers. Sidepull? Centerpull? Cantliver? V-brakes? U-brakes? Is it a road bike, touring bike or ATB? Dia-Compe made every type of caliper available on the market in '87, so if the calipers are original they could be anything that was available in '87. And maybe they're not even original. Pix, brake model name/number and bike model name/number should get you some helpful suggestions.

Cache

I just dumped a Dia-Compe rear brake for a minty older Campy Record Ti in black on my 1990 Cannondale. Works great! Still looking for a front brake replacement, sadly a set wasn't available. A bit spendy but I sold some stuff on ebay to fund my upgrades. What's your budget?

RobbieTunes

Look on the back of the DC's and see if there are any numbers like 39, 47, 59, or something like that. That would give you the reach. After that, for that bike, I think I'd go straight to Cane Creek or Tektro.

rccardr 

Best bet is Shimano 105, first generation, 1050 series. Excellent brakes, widely available, will work with any brake lever from that era. Polished, too. Next best would be Tektro R536, dual pivot, more pricey (around $55), but also widely available and a great set of stoppers. Cannondale also sold a series of house branded brakes that are out there on eBay from Wheel and Sprocket, they go for around $30 a pair. You can also use second ten 105 (1055 series) but they aren't polished and won't look as correct.

BaseGuy

My apologies for being too brief - my newbie status is showing:

It's a 1987 Cannondale SR400 "Team Comp" road bike. The previous owner upgraded the drive train to Shimano 600 SIS, so it now looks more like an SR600. The brakes in question are DiaCompe side-pull calipers, mounted to the front of the fork via a bolt from behind, with a nut and an acorn-style jam nut on top.

It is forever uncentered. It's a two piece caliper, so tightening the mounting bolt also puts too much friction on the fulcrum point of the two caliper halves and it binds them together. Loosening the bolt allows the whole caliper to swivel too much to one side, resulting in brake pad drag when off the brakes.

If I replace the whole fork with a more modern one (the original is a lugged-up steel thing), does that allow me to mount a modern brake more easily?

Thanks for the help, folks.

RaleighSport

I would have said the 105 1055 series, as they're plentiful cheap and dual pivot.

pcb 

No worries, thanks for the info. So we know it's a road bike, we know it's not original spec, some of the components have been changed/upgraded, and it sounds like you have recessed-mount DiaCompe sidepulls.

Properly setup your sidepull calipers should pivot smoothly and stay centered. Sounds like you have caliper setup/adjustment issues, not hardware problems.

The way sidepulls work is the caliper arm adjustment is separate from the mounting function, meaning tightening the mounting nut doesn't change the caliper arm pivot tension adjustment. It may look like that's what happening, but it's not. There's a shoulder on the pivot bolt, the rear of the shoulder contacts the fork crown, the front seats the caliper tension spring and rear arm. No torque is transferred from the mounting side to the caliper tension side. The pivot bolt will rotate when you torque the mounting bolt, though, so that will change the centering, and if one arm is hitting the rim it can seem like the pivot it now tighter, but it isn't. It's just badly centered and need re-centering.

Better calipers have a slot in the pivot bolt to accept a thin wrench used to center the caliper after installation. A lot of D-C brakes needed a 10mm wrench, other mfrs typically use a 13mm wrench. You can buy a vintage DC brake wrench if it's 10mm, or use a 13mm cone wrench for a 13mm. The cheapest brakes had no slots for a centering wrench, and are a bigger pain to center.

Can't go into a full sidepull setup tutorial here, plenty of guides online. The basic procedure is you pop out one side of the tension spring, adjust the arms to pivot smoothly without slop, reset the tension spring, install the caliper in the frame, torque down the mounting nut, then center the calipers with a wrench. Overall a simple procedure, but getting the caliper arm tension correct is trial-and-error, and if you don't correctly tighten the caliper tension bolt/nut, the arms will work loose and get sloppy and ineffective. There's always the possibility a previous owner/wrench mis-assembled the calipers, so you have to make sure all the proper pivot bushings are present.

If the brakes are cheap enough that there is no centering slot, they're not worth keeping IMO. Entry-level brakes like that have more arm flex and crappier pivots, cable attaching hardware, etc.

You can replace them with vintage Shimano 105 or 600 sidepulls if you want to keep the spec relatively period-correct and brand-consistent. Most folks like dual-pivot calipers better than sidepull, better stopping power with less effort at the levers. If you don't care about period-correct, anything folks recommend here will work well, ranging from vintage early Shimano 105/600 dual-pivots to current Shimano or Tektro.

Sounds like the fork is already setup for recessed-mount brakes, so there's no upgrade necessary to use better/newer brakes. Some of us like "lugged-up steel thing" forks better than aluminum or crabon, so unless you need to lose weight from the front end there's no need to touch the fork.

Photos would still help, a closeup of the calipers would tell us quickly whether they're worth keeping or not. The mid-/upper-level DC sidepulls were well-designed stoppers, most everybody's entry-level calipers were pretty crappy by comparison.