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daoswald 05-01-20 09:06 AM

Resolving bothersome brakes (disk)
 
I have a 2014 Cannondale Quick CX 3 with hydraulic disk brakes. The brake rotors have perforations along the surface. The pads make a ths-ths-ths-ths-ths-ths-ths-ths-ths-ths-ths sound as they clasp the perforated rotors while I'm braking. It's a little annoying, and I do wonder if those sharp perforations are biting into the pads such that they'll wear early.

I also find it really difficult to align the calipers so that they don't rub at all when I'm not braking, and so that they're not even noisier when I am braking.

I had a mechanic check the brakes over. He re-aligned them, but the next day I noticed that telltale squeak at low speeds indicative of the calipers rubbing the rotors. He also checked the condition of the rotors, and they appear to not be warped, and not wearing thin. The pads seem to have a lot of life left in them too.

Surely on a sub-$1000 bike with disk brakes, Cannondale probably is not using top-shelf components. I'm wondering if an upgraded set of rotors and hydraulic brake calipers would improve my experience.

This is a bike that I ride about 1200 miles a year for commuting, winter rides (because it accepts fenders), grocery-getting, and rides to the park with my kids. So it gets enough use for me to justify an upgrade to components that annoy me if doing so will improve the situation.

Would a brake upgrade help here?

bikeme 05-01-20 01:20 PM

It's not the perforations making the noise--all rotors have perfs. Upgrading the brakes would get you better braking (lighter weight, crisper action/modulation) but is not the cost-effective solution to your issue. I think it could be two things. The caliper pistons are not retracting or are sticky, placing the pads too close to the rotor--they need to be cleaned. When actually braking, if you get squeal, that means you have grazing or contamination on the rotors and/or contamination on the pads. Rotors can be wiped with 91% rubbing alcohol or stronger acetone or even be lightly sanded. Brake pads are hard to clean as they are porous and soak up gunk. You can try brake cleaner or acetone, sanding them or heating them with heat gun to burn off the gunk but I've found these are all weak answers at best and I buy new pads most times. Road spray, oil, bike lube, cleaners, etc are all possible contaminants. BTW, you can align the pads yourself. Get an allen key and slightly loosen the two screws on the caliper so it can move. Squeeze and hold the brake lever, (this allows the caliper to self-center) while retightening the screws (8-10nM torque, hand firm is good) then release the lever. Hope this helps.

dabac 05-01-20 02:49 PM

I’ve never had much luck with the self-alignment method. For me it has worked better to loosen the screws so that it’s just possible to nudge the caliper around by tapping at it with a screwdriver handle or comparable amount of force. Using that, I set the gaps by sight before tightening the screws again, little by little.

daoswald 05-01-20 04:15 PM


Originally Posted by dabac (Post 21449566)
I’ve never had much luck with the self-alignment method. For me it has worked better to loosen the screws so that it’s just possible to nudge the caliper around by tapping at it with a screwdriver handle or comparable amount of force. Using that, I set the gaps by sight before tightening the screws again, little by little.

Yes, this is the only approach that works for me. I have to visually verify that there's light coming through on both sides of the rotors.

daoswald 05-01-20 04:17 PM


Originally Posted by bikeme (Post 21449413)
It's not the perforations making the noise--all rotors have perfs. Upgrading the brakes would get you better braking (lighter weight, crisper action/modulation) but is not the cost-effective solution to your issue. I think it could be two things. The caliper pistons are not retracting or are sticky, placing the pads too close to the rotor--they need to be cleaned. When actually braking, if you get squeal, that means you have grazing or contamination on the rotors and/or contamination on the pads. Rotors can be wiped with 91% rubbing alcohol or stronger acetone or even be lightly sanded. Brake pads are hard to clean as they are porous and soak up gunk. You can try brake cleaner or acetone, sanding them or heating them with heat gun to burn off the gunk but I've found these are all weak answers at best and I buy new pads most times. Road spray, oil, bike lube, cleaners, etc are all possible contaminants. BTW, you can align the pads yourself. Get an allen key and slightly loosen the two screws on the caliper so it can move. Squeeze and hold the brake lever, (this allows the caliper to self-center) while retightening the screws (8-10nM torque, hand firm is good) then release the lever. Hope this helps.

I appreciate the suggestions. I'll clean the rotors, and may try replacing the pads. I imagine pads are not one-size-fits-all. How would I know what to replace them with? With rim brakes at least I can see the pads and verify I'm ordering the same thing.

bikeme 05-01-20 05:20 PM


Originally Posted by daoswald (Post 21449702)
I appreciate the suggestions. I'll clean the rotors, and may try replacing the pads. I imagine pads are not one-size-fits-all. How would I know what to replace them with? With rim brakes at least I can see the pads and verify I'm ordering the same thing.

You're welcome. Pads do come in different styles. The easiest thing to do is remove your old ones and match the part number on the back of the pad as well as visually match at your LBS or online. There are some third party pads but I buy the OEM ones. You also may have a choice between resin (aka organic) pad material or metal, match what you currently have. BTW, to clean your pistons, wipe around them with some rubbing alcohol before pressing them back into the calipers (I use a wide plastic tire lever like a Pedro's--don't use metal like a screwdriver).

cyccommute 05-01-20 06:51 PM


Originally Posted by daoswald (Post 21448900)
I have a 2014 Cannondale Quick CX 3 with hydraulic disk brakes. The brake rotors have perforations along the surface. The pads make a ths-ths-ths-ths-ths-ths-ths-ths-ths-ths-ths sound as they clasp the perforated rotors while I'm braking. It's a little annoying, and I do wonder if those sharp perforations are biting into the pads such that they'll wear early.

I also find it really difficult to align the calipers so that they don't rub at all when I'm not braking, and so that they're not even noisier when I am braking.

I had a mechanic check the brakes over. He re-aligned them, but the next day I noticed that telltale squeak at low speeds indicative of the calipers rubbing the rotors. He also checked the condition of the rotors, and they appear to not be warped, and not wearing thin. The pads seem to have a lot of life left in them too.

Surely on a sub-$1000 bike with disk brakes, Cannondale probably is not using top-shelf components. I'm wondering if an upgraded set of rotors and hydraulic brake calipers would improve my experience.

This is a bike that I ride about 1200 miles a year for commuting, winter rides (because it accepts fenders), grocery-getting, and rides to the park with my kids. So it gets enough use for me to justify an upgrade to components that annoy me if doing so will improve the situation.

Would a brake upgrade help here?

A new rotor might help. Rotors can make all kinds of weird noises under the pressure of braking. Avid Paragon rotors that came standard with Juicy 7s sounded like a turkey at mating season whenever the brakes were applied. It could also sound like the brakes were boiling. I never got used to them and wasn’t satisfied until I replaced them. I’ve used Magura Storm SL and they are fairly quiet. I currently use Ashima Ai2 rotors which also seem very quiet.

For centering the brakes, pulling the lever is going to center the brake better than any other methods. Tapping it with a screwdriver is a coarse adjustment at best. There are a couple of things that can help. First...and probably foremost...make sure the wheel is in the fork tips. It’s easy to get the wheel cocked just a little to one side or the other and even a very slight misalignment can result in the rotor being slammed up against one pad or the other. The amount of space you have between perfect alignment of the rotor and rubbing is tiny.

When you do pull the lever to clamp down on the rotor, pull it hard and use a toe strap to hold it while you tighten the bolts on the caliper. Make sure the caliper bolts are very loose before you start.

Finally, I’d suggest using a Birzman rotor gap tool on hydraulic brakes. It really helps to set the gap....and it gives you a good idea how much gap there is between the pads and the rotor.

DrIsotope 05-01-20 08:31 PM

If I've searched correctly, that bike has the Cannondale Helix 6 brakes, which are rebadged Bengals. Typical inexpensive OEM stuff-- you can buy the F+R Helix 6 levers +calipers with rotors for about $65 on eBay.

I'd start with new pads-- the pads for Bengal/Hayes/Helix are inexpensive.

If you'd rather go the route of replacement, your options are limited only by your budget-- there are a ton of options out there in the ~$100 area.

cpach 05-01-20 11:01 PM

Normally I might recommend to not worry so much about it, or check for contamination, but those OEM brakes are legit not super great. For really basic use Shimano MT200 are fine, the MT400 are pretty much the same but with shorter brake levers which is nice. Shimano Deore level is legitimately quite nice and all I'd recommend for your needs. New matching rotors wouldn't be a terrible idea if you went this route.

GamblerGORD53 05-02-20 12:28 AM

Looks like yet another LAME over complicated technology. Pffft. Can't get oil on the rotor using a cable. LOL Looks like a silly lot of holes in that rotor too.
Anyway, I haven't broken a cable since my 1974 Raleigh.
I have 3,000 miles with my TRP Spyre on a 203 mm Rohloff disc. I installed it on a tour, on a 120 lb bike. Didn't clean nothing and the disc was on there 1,500 miles before. Went to a hill and it locked easily first time and every time since. ZERO squeals. It has compressionless housing.
I have long pull SA levers and the gaps are almost a dime. LOL My setup has slots for a horizontal dropout.
My SA drum brakes never made a peep either.

Before this I had POOR one-sided BB5s that also squealed like a pig when wet. Semi metalic pads are a dumb idea, IMO.

daoswald 05-02-20 07:54 AM


Originally Posted by GamblerGORD53 (Post 21450393)
Looks like yet another LAME over complicated technology. Pffft. Can't get oil on the rotor using a cable. LOL Looks like a silly lot of holes in that rotor too.
Anyway, I haven't broken a cable since my 1974 Raleigh.
I have 3,000 miles with my TRP Spyre on a 203 mm Rohloff disc. I installed it on a tour, on a 120 lb bike. Didn't clean nothing and the disc was on there 1,500 miles before. Went to a hill and it locked easily first time and every time since. ZERO squeals. It has compressionless housing.
I have long pull SA levers and the gaps are almost a dime. LOL My setup has slots for a horizontal dropout.
My SA drum brakes never made a peep either.

Before this I had POOR one-sided BB5s that also squealed like a pig when wet. Semi metalic pads are a dumb idea, IMO.

I wouldn't go so far as to say I really dislike disk brakes. But they are more work than rim, for sure. And noisier. They grip better, though, and I live in hilly terrain. But my Synapse has rim brakes, and I never really felt they were inadequate in any way. The Quick came with disk, and while they are better in some ways, they're worse in others.

GamblerGORD53 05-02-20 08:19 AM

I was ranting about HYDRAULIC brakes actually. I HATE rim scratch brakes that are also bothersome to take the wheel off.
My cable TRP caliper is working perfect. But my front drum brake will outlast a bunch of disc pads.


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