Bicycle Mechanics - Any cheap way to upgrade these brakes?

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Jerseysbest
11-19-05, 01:40 PM
I have a mtn bike with real nice roads tires, but I also have an old road bike thats great to ride, but the brakes are terrible. I'd prefer to have the road bike to ride to my 30 or so miles a week on, but at 250lbs and riding in a congested areas, these brakes don't cut it...
I've been looking around the internet for ideas but I have no clue. I have tools and am very mechanically inclined, I just never wrench on my bikes.
Here's pics of the brakes that are on it now:
http://img.photobucket.com/albums/v191/jerseysbest/bikefront.jpg http://img.photobucket.com/albums/v191/jerseysbest/bikerear.jpg
Anything I can do for cheap? The pads a old and dry, and probably could be replaced, but I've been putting it off figuring I'd replace the whole thing sometime soon, but I dunno I what I'm doin here. Thanks for any help or pointers, or whatever.
Mike
Autokat
11-19-05, 02:15 PM
I have the same brakes on my bike , I changed the pads and adjusted the toe in so the front of the pad hit the wheel first and they work great . By adjusting the toe in when you apply the brakes and the front hits it pulls the rear of the pad on and as the wheel tries to turn it grabs harder , like this but not as extreme as this.. \l l/ ,.. then they do this when applied... ll ll ...
I'd suggest new pads and toe-in as well. You want the part of the pad toward the front of the bike to contact first. I like about a dime's thickness worth difference, which can be done with a dime. A rubber band works nice too. This also will eleminate squealing too most of the time, in case anyone is reading that is sqeaking!
Jerseysbest
11-19-05, 04:27 PM
Thanks for the replies, stop by the bike store monday morning and see what they got and hopefully be able to ride it this week.
spider-man
11-19-05, 04:44 PM
While you're changing the pads, clean the braking surface of the rim.
Kool Stop continental brake pads. They won't cost more than 8 bucks a pair, or so, and they will be dramatically better than the old pads. They are always my first upgrade upon picking up an old bike like that.
caotropheus
11-20-05, 12:38 AM
you can use a simple strap of steel and drop closer to the wheel your caliper brakes. Take a look at Sheldon Brown's article
http://sheldonbrown.com/home-drop.html
The closer the pads are to the bolt of the caliper, the strongest the breaking power.
MichaelW
11-20-05, 05:05 AM
Diacomp are fairly good brakes. I had a really low end set of Weinnman calipers that were so bendy. I swapped them for a modern pair of Shimano dual-pivbot style calipers and the diifference was amazinng. Modern brakes may be a bit heavier in some cases but are much more solid and powerful.
Decent brake blocks can make a difference.
HillRider
11-20-05, 06:19 AM
These appear to be "long reach" (47 to 57 mm from the pivot bolt to the rim center) brakes. Tektro makes a decent set of double pivot long reach brakes at very attractive prices. Harris Cyclery has them and they will be major upgrade in both power and adjustability.
king koeller
11-20-05, 06:46 AM
Those Dia-Compe are great brakes. Remember brakes can only work to full advantage if the wheels are true,... I mean perfectly true.
The calipers need to be oiled at the pivit bolt and checked for smoothness. Center the caliper's with a centering tool, usually a cone wrench and spray some wd-40 in the cable housing, check for old rusty cable that can be replaced. The toe-in suggetion is right on the money, eliminates squeels, and improves performance, and lastly get some cool stop pads, the best in the business. remember cables stretch, adjust pads 1/16th off of rim, making sure the pads are in line with the rim and not too high(rubbing the tire) or low (off the rim) . set the adjustment barrels at 50% to allow for future cable stretch,(unscrewing the barrel to reset proper spacing) or wheel out of true(screwing in the barral to move pads out away from rim. These DIA-COMPE brakes can be the best brakes out there for the money if you set them up correctly. they last forever, are light, easy to adjust, and stop on a dime. try out those cool stops, ( like old Matthauser pads) good luck!
Those are some classic Dia-Compe sidepull calipers, long reach. They're really good, so keep them. (Just don't toss them). Try some new pads, since the pads on those may have deteriorated. Kool-stop pads are worthwhile, and toe-in is a good installation technique.
What shape are your cables in? If they are stretched or corroded, you might want to change those first.
In any case, I doubt the problem is the calipers.
Thanks for the replies, stop by the bike store monday morning and see what they got and hopefully be able to ride it this week.While you are at it get some new cables and inexpensive bulk casing. Do the whole job and do it right.
Sheldon Brown
11-20-05, 09:35 AM
I have a mtn bike with real nice roads tires, but I also have an old road bike thats great to ride, but the brakes are terrible. I'd prefer to have the road bike to ride to my 30 or so miles a week on, but at 250lbs and riding in a congested areas, these brakes don't cut it...
I've been looking around the internet for ideas but I have no clue. I have tools and am very mechanically inclined, I just never wrench on my bikes.
Anything I can do for cheap? The pads a old and dry, and probably could be replaced, but I've been putting it off figuring I'd replace the whole thing sometime soon, but I dunno I what I'm doin here. Thanks for any help or pointers, or whatever.
I get basically this question by email all the time, so frequently that I have a canned response ready to send with a couple of mouse clicks. Here it is:
A caliper brake system consists of 4 parts:
•The levers
•The cables
•The calipers
•The brake shoes
All of these parts are upgradable. Many people think first of replacing the calipers, but, in fact, this is the least likely part to make any real difference. A caliper is a simple leverage unit, and there's not all that much to one.
In the case of older bikes, it can be difficult to find a new caliper that will even fit.
The other 3 parts are much more likely to yield real improvement.
•The levers
Older designs had the cables exit up from the front of the brake levers, arching over the
handlebars. The newer style, where the cable exits out the back of the lever and runs under the handlebar tape is referred to as "aero" because it eliminates the wind drag of the exposed cables.
Aero levers are generally a major improvement over the older type. The pivots are located differently, making it possible to get fairly serious braking from the position where the rider's hand is on top of the lever hood. Traditional levers would permit the use of this position for gentle deceleration only.
Additionally, the better aero levers have better internal cable routing, so there's less cable friction. I particularly recommend the Shimano Tiagra units we sell for $39.95, including cables. See: http://sheldonbrown.com/harris/brakes.html#leversdrop
•The cables
Older cables used metal-to-metal contact as the inner cable slid through the spiral-wound steel housing. Lubricant was by grease, if the mechanic was conscientious.
Modern cable housings have a Teflon or similar lining. The better inner cables are stainless steel, and are "die drawn" to make them smoother. The result is greatly reduced cable friction, so more of your finger strength is transmitted to the caliper, rather than wasted overcoming cable friction.
•The brake shoes
Modern high-performance brake shoes also make a considerable difference. The very best is the ugly salmon-colored material originated by Scott-Mathauser, and now sold under the Kool Stop name. See: http://sheldonbrown.com/harris/brakeshoes.html
All the best,
Sheldon "Stop!" Brown
+-----------------------------------------------------+
| If a little knowledge is dangerous, where is |
| the man who has so much as to be out of danger? |
| --T.H. Huxley |
+-----------------------------------------------------+
Oh, and get rid of that big reflector. Use one of the small blinkie battery-powered rear LED lights instead. Much more effective and better looking.
Jerseysbest
11-21-05, 05:15 PM
Thanks for all the suggestions and tips, I really appreciate them. I stopped by the local bike store but all they had were the cheap generic type pads you'd find at Kmart, so I ordered some Koolstop pads online as well as some 27" tires and tubes.
I was hoping to get some road riding time this holiday weekend but I guess I'll just stick to the mountain bike trails again.
And, yeah, I've been looking into getting some front and rear LED lights to replace those big reflectors, but I'm rarely out past sundown.
Regarding the toe-in on those brakes, can that even be set? Looks like there are no hemi-spherical washers in that assembly.
The really old-school way to set toe-in, or so I hear, is by using pliers to bend the calipers a bit. I generally just don't bother to do it with old bikes that I've set up, but perhaps I should. Old brake pads (even the old-style Kool Stop continentals) don't have hemi-spherical washers.
Bikewer
11-21-05, 07:55 PM
Hehe- I have bent a few of those old calipers; a small crescent wrench works well. Nashbar has a set of their-brand dual-pivot long-reach brakes at attractive prices.
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