Bicycle Mechanics - Upgrading brakes

Hi all,

This past spring I bought a new road bike, cyclocross bike actually. It was on sale because it was last years model (2001). It's a LeMond Poprad. It came with Shimano Sora components. Since they had it on sale so much, I told them to rip all those off and upgrade them to all 105 with a triple chainring in the front. I was going to upgrade the brakes too, but they said the one's on there were fine. It came with Avid Shorty 4 brakes. They also said if I upgrade to road brakes, then I would limit myself to the different wheels I could put on it. Well, I've basically decided not to put anything but road wheels on it for the future since I have an old beat-around mountain bike for riding off-road or trail riding. I am not really happy with the Avid brakes at all. They are very weak, and the front brakes tend to shudder if I apply them hard. In fact, they can shudder to the point that I have almost been thrown over the handle bars on 2 occasions. I would really like to upgrade the brakes to something stronger.

Would changing to Shimano 105 or Ultegra brakes be better? Are those brakes better? Suggestions for brakes are greatly appreciated. I'm a big guy (6'2", 250+).

Thanks,

PBW

Is the fork crown and seatstay bridge drilled for road calipers?If not,you have a problem.The other problem may like be with the way your present brakes are setup.Avid shortys are often recommended. If you are spending the money,may as well go for ultegras.If the Avids are almost throwing you over the handlebars waen't they TOO STRONG.I don't get it.

Sometimes cantelevers misbehave because the straddle cable is not the correct length. You can change the modulation with more stradle cable and less brake cable.

http://www.sheldonbrown.com/cantilever-geometry.html

Caliper brakes come with different amounts of drop (clearance for tyres). You need the right size for your forks.
If your fork is drilled, and has clearance for CX tyres, it may be the correct length to fit a long drop caliper.
Short drop calipers (standard Shimano/campy racing ones) have room for 25mm, sometimes with a fender (at the very most a narrow 28 without fender).
Longer drop ones (Shimano 105 long drops) can take a 32mm tyre with fender. That is more than enough for any road riding.
You cant fit a long drop brake to a close clearance fork, or visa versa.

Drop does not necessarily relate to clearane for tires as much as it does the ability of the pads to reach the braking surface on the rims.shimano is now also marketing long reach or drop dual pivots.

Originally posted by pokey
Is the fork crown and seatstay bridge drilled for road calipers?If not,you have a problem.The other problem may like be with the way your present brakes are setup.Avid shortys are often recommended. If you are spending the money,may as well go for ultegras.If the Avids are almost throwing you over the handlebars waen't they TOO STRONG.I don't get it.


Well, they aren't really too strong because they don't really help me stop. It's hard to describe what they do, but I'll try. They start to catch as the pad hits the rim and then it's like the pad jams and the front wheel is jammed back at me. It actually feels like the wheel and fork are both moving into me at the same time. Then something releases and it pushes back forward. It does that back and forth really fast, but I don't feel much stopping power, but it's enough to shift the weight forward. It actually feels like a very strong shudder.


I talked with another cyclist here at my office and he mentioned that since I replaced the components with Shimano 105, including the shifters and brake levers with the STI shifters/brake levers, I should have also changed the brakes. He said the brake levers I have are not meant to be used with these types of brakes (Avid). He was actually surprised that the LBS didn't say something when they were replacing all the components.


He also recommended just going to Ultregra. He also said my brakes were badly aligned and adjusted. He showed me how to properly center them and adjust the cable tension. I tinkered with it for about an hour last night and I think I have them properly aligned and adjusted now. I haven't had a chance to ride it unforunately.

I'm still going to take it into the LBS and ask them about upgrading to Ultegra.

PBW

Well,

As you have found out when discussing with your collegue, adjustment is one key issue with cantilevers.

Geometry is one factor, as seen in Sheldon Brown's web page -- adjusting the height of the straddle bridge may help.

Another issue is brakepad distance : they should be set so they hit the wheel when the brake levers are vertical or slightly slanted outboard. If they are slanted inboard, brakes will tend to be less efficient when you brake hard.

A third important issue is the quality of brake pads. Standard issue Shimano brake pads are cheap, but they wear relatively quickly, wear out the rims quickly, and aren't that effective. Try a set of Kool Stop Salmon pads (better in all types of weather, but a little bit too "grippy" under a nice sun), or a set of Koop Stop Dual pads (rear half salmon, front half black -- smooth under the sun, yet powerful in rain or snow). As an added bonus, Kool Stop pads are also more gentle to your rims.

If you aren't sure about your brakes, only buy a set of pads for the front wheel and try them.

Regards,

i've got avid shorties on my jamis cyclocross bike. they are not my favorites but i have learned to live with them.

your problem is almost certainly related to how the pads are adjusted in the calipers. they should be adjusted so that they are "toed in" slightly ... the leading edge of the brake pad should touch the rim first, but only a bit. this solves some (but not all) of the squealing problems. prior to toeing my pads in, my brakes yelped like a stuck pig. now they only squeal a little bit.

here are a few things to keep in mind in considering converting to caliper (ultegra) brakes:

1) caliper brakes do not provide much clearance for fenders.
2) your forks and frame likely have brazed-on bosses for cantilever brakes. if you take off your cantilevers and use calipers instead, you will have big ugly bosses exposed that are no longer concealed by brakes.

I can attest to what Bandit says. I have a Lemond Poprad with Avid Shorty cantis and ran into this problem. It was resolved by "toeing-in" the brake pads as Bandit suggested. When properly adjusted the brakes should work just fine.

Yes, I had to do the same thing... toe in the brake pads. For the most part, they don't squeal too much. If they get wet, they squeal a bit more, but that is to be expected. Generally, they will squeal once or twice per ride, depending on how long and how far I go.

I'm not really concerned about the squealing. That I can handle. It's the fact that I don't really feel like I have good strong braking power that I'm worried about. I've had some close calls and I'd really like to have stronger brakes.

I might just ask the LBS what my options are and what they suggest in terms of getting more braking power. See what they say.

PBW

Road brakes simply aren't very powerful, it sounds to me like you need to learn to move your body when you brake (in addition to the aforementioned adjustment issues). As in, move your toosh back and apply more front brake when you need to stop fast. You could put v-brakes on your bike but you would need to find one of those little pulleys that allows your road levers to pull enough cable. One other idea ... you could try top mount brake levers (we use them in cyclocross racing) they give you slightly better modulation and power. http://shop.store.yahoo.com/cyclocrossworld/topmounbrakl.html

UPDATE:

I chatted with the service manager at my LBS. Changing to caliper brakes is pretty much a no-go. The regular caliper brakes (shimano dura-ace, ultegra, etc) will not fit because the distance between the hole in the fork to the wheel rims is too great. They do make calipers that allow for more distance, but according to him, they do not work very well and they have had many problems with them.

The other option is to try going to linear brakes. But that entails using some kinda gizmo that is also iffy. He also said these will not be very strong. Plus... they don't lend themselves to feathering the brakes very well. He said they are either "on" or "off". So, not good for pacelines.

So, we basically tossed out those two ideas. What we are going to try is:

1st... try a new brake pad. See if that solves the problem.

2nd... upgrade to a better different cantilever brake. He showed me some Shimano Altus brakes (which I happen to have on my old mountain bike). He said they've been around for a long time and he thinks they work great. If they are anything like the one's I have on my mountain bike, I think they work great too. In fact, the reason I'm trying to upgrade is because I think my brakes on my road bike should be as strong as the brakes on my mountain bike, maybe I'm wrong to think that.

3rd ... if neither of those two options work.. then we'll try going to a V-brake, something like a Shimano XTR or Shimano Deore Xt.


So... he's ordering the brake pads... I'll keep ya updated. Also, I'm wasn't the first person to come to them and complain about the Avid brakes on this type of bike. Apparently they just don't work well. Plus the squealing is a problem on almost every biek they sell.

PBW

i, for one, would be most grateful for posts on your progress.

The long drop caliper brakes from Shimano work very well and are comparable in performance to good cantelevers (I use both ). Calipers are only weak if you use cheapo 1970s Weinman ones.
You may have too much clearance for the longer drop ones to work, but it is worth measuring up.
Your bike shop may not realise that they are avialable, since they are not part of any groupset but they are still made. Have a look at Rivendell.com for more info.

Originally posted by MichaelW
The long drop caliper brakes from Shimano work very well and are comparable in performance to good cantelevers (I use both ). Calipers are only weak if you use cheapo 1970s Weinman ones.
You may have too much clearance for the longer drop ones to work, but it is worth measuring up.
Your bike shop may not realise that they are avialable, since they are not part of any groupset but they are still made. Have a look at Rivendell.com for more info.


Yeah, the guy at the LBS mentioned them... I did too in my post. I just forgot they were called "long drop" caliper brakes. Those are the brakes *he* thought did not work very good and have had problems with in the past. He thought they would probably work on my bike (he knows the bike I have), but he said they weren't a good solution.

He also said caliper brakes are very good. He actually preferred them. I think he actually mentioned the fact that in the beginning they sucked, but now they were as strong, if not stronger than any of the other brakes out there. But the fact that I need long drop calipers was not good.

I have a feeling I will be going with the Shimano Altus Cantilever brakes. But I'm going to at least try new brake pads first since that is the cheapest solution.

But I will report back and let ya'll know how it goes.

Thanks for all the help.

PBW

Hey Bandit,congradulations!
I think you may have solved the mystery of the squealing brake pads. I've putting up with this(noise) for way too long. now maybe some of us of the non-technical crowd can ride in peace and without the embarrassment.
Thanks,guy!
P.S. If this works I'll mail you a beer! :beer:

only ONE beer? i'm german, y'know.

UPDATE:

Tried new brake pads. They are much better. Feels like they have more power and grab. They are Aztec 2 brake pads.

Still didn't stop the shuddering and squeaking. Took it into the shop today. After he gave me a free trueing in both wheels, we decided to upgrade the front brakes to Shimano Alivio cantilever brakes. The squealing has totally stopped. And for the most part, the shuddering has stopped.

He thinks it's the fork that is giving under the strain. The only way to fix that is to upgrade the fork. I'll hold off on doing that until I've put some more miles on it and see how I like this. I think this setup just might be ok for me.

PBW

P. B. Walker;

I have been counseled by both a professional road racer and a master mechanic that Kool Stop offer pads that are significantly more versatile in the amount of actual stopping power experienced under the various conditions which they are designed to accommodate.

Also be advised that Avid strongly cautions against using the Shorty 4 with brake levers that are not designed for center-pull cantilevers. Avid's instruction sheet is available at

http://www.avidbike.com/7_techinfo/Shorty4-0202.pdf

I hope that you might find merit and benefit from Avid's guidance on the aforementioned. Experience has taught me to always at least examine the vendor’s data/instruction sheets and test their methodologies before experimenting with variations. I can cite only a handful of cases where this wasn’t valid. Note: Avid advises to do a "Pad Cartridge" upgrade for more stopping power in their data sheet.

Trust the pad replacement proves the performance you desire. I would greatly appreciate an update to this post with your findings. Thank you for your diligence..

faith, you bring up a good point about the brake levers not matching with the avid cantilever brakes. A guy I work with who is big into working on bikes and building them suggested the same thing. The mechanics at the bike shop didn't say anything about this. Plus, when I had them change the whole drivetrain to Shimano 105, they said the STI shifters/brake levers would be fine. I would have thought they'd have said I needed new brakes too if they would have been a problem... I mean.. hell, more money for them.

I will say.. when I switched out to these new brakes on the front (from Avid shorty 4 to Shimano Alivio) he didn't charge me for the new brakes. He said he would send them back since I've been having problems with them since the beginning.

I think these new brakes are going to work out well. In fact.... I took it around the parking lot.... and did alot of high powered braking... I can actually see the fork moving as I brake. I think the fork is bending as I slam on the brakes.

I'll keep ya'll posted if something new comes up...

PBW

i also had avid shorty-4's and no matter what they just were never that good. i actually replaced my bars with flat carbon bars and then switched to xt v-brakes and xt shifter/brake levers and i just couldn't believe how strong and powerful they were! my lbs said to be careful because people have actually crushed their rim with too much brake pressure,i can see that happening, if a grab a hand full of front brake i stop NOW and with out care would definately go over the bars.i have never used the roller thing on these brakes so i can't comment on those but i would never use any other brakes than v-brakes.with the shorty's on the rear if a braked hard they would feel mushy and slip but now i grab rear brake and skid like a little kid with coaster brakes.i actually like the flat bars much better than the drops anyways so the switch didn't bother me, people say you can't ride long without drop bars but i have never hada problem doing centuries and all day riding. a lot of it has to do with seat and stem height too, if you have a low seat height and a high stem where yoyur arms are higher than your shoulders then you're going to be uncomfortable,but with a high seat and level or low stem and bars you'll be fine.

PBW, I have had the EXACT same troubles that you had (in fact I think they're re-occuring, more on that later) I had Avid Shorty 4s on my 2004 Kona Jake. They SQUEALED and CHATTERED really hard. Under hard braking, the front would chatter/shudder so hard that it could send me over the bars! When I looked down, while brkaing, the fork was vibrating fore and aft about 2-3 inches!! :eek:

After some research I found that Avids are notorious for squealing. They squeal because they're machined so thin that they are actually flexing under braking, and thats wat causes the squeal. With the brakes actually flexing, and vibrating, I believe it was throwing the harmonics (does that make any sense?) of the fork out of tune.

So I got the new Shimano Cantis (I did try diffrent pads, with the Avids: The stronger the pad, the more severe the chatter!) At first they were squeal, and chatter, free.

But lately, now that the weather is getting colder, they've developed a squeal and a chatter :mad:
I now think it's my fork thats the cause of the chatter! After a bit of consultation at my LBS, I'm going to go look around for a new fork.

So, PBW, I'm curious as to what solutions you may have found for our common problem. If anyone out there has any suggestions...

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