Mountain Biking - Disc Break Problems

I have a Kona Blast, i use it quite often around the city and doing so off roading, i also use it to do small drops and jumps etc. I have had it since march this year. I could feel my disc breaks (mech) were getting abit lose, so i chose to tighten them myself. They were great for the 1st day afterwards, but after doing some small lips and off road on wet grass they wernt working very well, i had to really pull on the lever to make them break and i could no longer pull skids (not that i do very often but i was just testing them). i thought that it was just because they were wet, and therefor not working to the full. But when taking the bike out the next day the breaks were the same.
I want to know what i can do about this, should i try tightening my brakes again? Or is it posible that my break pads have gone? i didnt think pad could wear away so quick and in such a short amount of time.
i am going to do some cross country and downhilling this weekend and they ned to be working properly by then.
Cheers for any help
Aidan

on the oppisite side of the calipur theres a little allen head screw tighten it untill just before the pad rubs. i prety sure thats what you problem is.

i have tried just tightening my brakes (by pulling the cable through more). this works a little bit, but when i brake it does not stop instantly as it did before, the bike jus comes to a gradual stop.
Does this mean my pads have worn away?

if you lay your bike on its side with the disk side down and look through the wheel at your brake there is a little allen head bolt tighten it a few clicks. spin the wheel, if it doesnt rub then tighten it a few more untill just before it rubs.

ill give it a go but i tried that and it bubbed on the wheel straight away

rubbed*

ok then maybe you pads are contaminated.

so if i need new pads, do they cost a lot and will i be able to fit them my self (im not the most experienced work man but i know some stuff)

How about try and clean the rotors first if you havn't already. Use denatured alchol (metho spirits) and give them a good clean. If braking still sucks then your pads are most likely the problem. Pads, depending on quality, depend on price obviously. I'd say you would be able to fit them yourself, just gotta be carefull removing/installing. Take the wheel off, un-tension the brake, and there should be a pin thing you un-bend or slide-out that will allow you to release the pad. This might change depending on brake models, not really sure.

But just make sure that everything is tight and the pads are well cleaned before going out and buying new pads.

im going to the bike shop now, ill tell you how it went in a hour or so

guy at the shop told me that the pads were prob contaminated, so i bought some new pads and will try to fit them tonight... can anybody give me any suggestions to help me stop these new pads from becoming contaminated.

guy at the shop told me that the pads were prob contaminated, so i bought some new pads and will try to fit them tonight... can anybody give me any suggestions to help me stop these new pads from becoming contaminated.
Watch out when handling oil near the rotor or pads as I think that can really contaminate them.

ahhhh, that could be it... ive got a vfeeling my friend sprayed some WD40 on the breaks just before they started not working, could this of contaminated them

More likely. Like what Drunken Chicken said, any type of oil that gets on the rotors or pads make the worst sound ever. In other words you would need to get new pads. Just always remember to rub Dentured Alochol (Methylated Spirits) on your rotors. Works well :)

it also says on the the brake pad packaging that there will be a burn in period - how long will this be?

it also says on the the brake pad packaging that there will be a burn in period - how long will this be?
The break-in period? Whew, try searching, there's no real set amount of time, everyone has their own opinion on how much time it takes/how you can break them in fastest. :)

ahhhh, that could be it... ive got a vfeeling my friend sprayed some WD40 on the breaks just before they started not working, could this of contaminated them
You'd better believe it. You need to plant your foot squarely up your former friend's ass for that one.

so if i need new pads, do they cost a lot and will i be able to fit them my self (im not the most experienced work man but i know some stuff)

Most pads have wear marks to show you when they are worn through. If thats the case, you should see some metal inside the pad surface.

Otherwise, I would suggest that you sumberse your pads in denatured alcohol overnight. Clean them with a paper towel. Re-install them. They should be better at first but not "great" until you wear them in once again.

The alternative is to buy a blow torch and simply burn the contaminats off. But this will leave a glaze on the pad surfaces which you'll have to sand off.


Finally, keep any SPRAY LUBES well away from your discs and rotors. No more spray lubing for you. That crap really doesn't work well anyway.

AFTER you ride, put the chain through a cleaner an THAN LUBE. Use drops and put a single one on each chain roller. Let it settle overnight. This will keep the lube for splattering onto your breaking surfaces.

guy at the shop told me that the pads were prob contaminated, so i bought some new pads and will try to fit them tonight... can anybody give me any suggestions to help me stop these new pads from becoming contaminated.

Well, I hope you cleaned your rotors first (with denatured alcohol (isopropyl doesn't work)). Otherwise, you'll contaminate your new pads as well.

it also says on the the brake pad packaging that there will be a burn in period - how long will this be?

Find a long hill you can pedal down. Pedal HARD down it while you apply the brakes. When you can easily lock up the wheels, the pads are bedded in. The harder you pedal, the quicker this will go.

so ive cleaned the disc and rotors and installed the new pads, i did the front wheel 1st... when i put the wheel back on i could not have the brakes as tight as i liked them because they were rubbing against the disc. is there anywhere other than the cable you pull through and the allen key slot on the back of the caliper that i can loosen the pads so that i can tighten the lever.

when i put the rear wheel on, after installing new pads, the same problem occured again but much worst. i have totaly losened the allen key slot on the back and let the cable go very lose, but the disc still rubs also as the cable is so loose when i pul the lever the break does not react. Therefore is there somewhere i can losen the pads to stop them rubbing.

there are 2 other allen key slots near the one i losened on the back of the caliper, do these losen the pads

sorry if this is hard to understand but i found it difficult to explain
cheers for any help

so ive cleaned the disc and rotors and installed the new pads, i did the front wheel 1st... when i put the wheel back on i could not have the brakes as tight as i liked them because they were rubbing against the disc. is there anywhere other than the cable you pull through and the allen key slot on the back of the caliper that i can loosen the pads so that i can tighten the lever.

when i put the rear wheel on, after installing new pads, the same problem occured again but much worst. i have totaly losened the allen key slot on the back and let the cable go very lose, but the disc still rubs also as the cable is so loose when i pul the lever the break does not react. Therefore is there somewhere i can losen the pads to stop them rubbing.

there are 2 other allen key slots near the one i losened on the back of the caliper, do these losen the pads

sorry if this is hard to understand but i found it difficult to explain
cheers for any help


1. Depending on your brakes you CANNOT adjust the 'toe' of the pads unlike normal 'v-brakes'. Although you CAN tighten the cable tension at the brake levers if you dont want to use the allen key hole. Where the rubber housing comes out of the lever there will be a notch. Screw it out, you will tension the cable, tightening the brake (screwing it back in will loosen it back).

2. V-Brakes are a lot better to adjust, you have 3 options and you can get a perfect non-rubbing wheel with perfect tension, thats what I LOVE about them. Lower end disk brakes dont have the 'toe' features (like V's) to my knowlegde that can move the location of the pads. You really only have one adjustment, and that is the cable tension. Although I must add different models of disks have different features so you might be able to adjust the positioning of the pads but that would depend on brake model, so i couldn't really help you there.

im going to the bike shop in about an hour i'll see what they say

on the subject of 'toe' ing, ive noticed that my rotor is at a bit of an angle to the pads and cant seem to fix it. Whats up with that?

so back from the bike shop, the guy says: i have to take the wheel off, put a small screwdriver between the pads to open them out a little bit, as they sometimes stick together when installing them...
has anybody else had this problem, and does it sound like a reasonable explanation

on the subject of 'toe' ing, ive noticed that my rotor is at a bit of an angle to the pads and cant seem to fix it. Whats up with that?
Incorrect setup. What brand and model brake?

On mine, the entire assembly was too far to one side, and the hard application of brakes was actually pushing the rotor into the caliper housing itself. (The pad adjustment on that side was completely backed off) I had to loosen the two allen head bolts on the backside and slide the whole mechanism over about a millimetre or two to centre the disc in the opening again. Since then, no worries.

When I have replaced pads, the interior of that mechanism seemed pretty simple to me; caliper, pad, spring, pad, caliper. Would never presume to second-guess the mechanic, but I can't fathom how or why he would need to pry the pads apart.

Unless your brakes are substantially different than mine. ('05 Fire Mountain)

Hope this may be helpful.

i have fixed the problem... i took the pads out and steched the springy metal bit between the pads, then put the pads back in... thi sseemed to work
now all i have to do is wait for the break in period is over and ill have some nice brakes onece me :-)