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Braking problems are breaking me :(

Clockworkmark31Clockworkmark31 Posts: 1,053
edited January 2014 in MTB workshop & tech
Hello everyone.

I'm new to these forums having just got back in to mountain biking, after a 3 year gap when my old love got stole.

Things seem to have moved on quite abit.

Anyway just got a new bike after noticing the weight creeping up, so after 6 weeks Ive lost 10kg now 98kg.

My problems are my brakes driving me mad.

First they worked perfect, then needed bleeding. Then after a good cleaning of the bike I accidentally got MUC OFFs PTFE spray on the discs lesson learn t when I grabbed the lever I got nothing.

So cleaned the disc 160mm Avid rotor light sanded the pads, braking didnt seem good until they bedded in again, seemed fine until I thought I want a bit more bite.

Being abit heavier I replaced the front rotor with a hope 183mm floating disc, and left the 160mm avid rear. New pads all round. Bedded them in again and good performance.

Now here is my problem, with it being winter I have to clean my bike after every ride. (see pics after todays ride)
Use water first get rid of most of the muck, then use MUC OFF then rinse and dry. dont touch the discs now as I understand I would be removing pad material from the rotor.

But then when I use the brakes again performance is rubbish for a few miles then they bed in again.

Surely I am doing something wrong or the brakes are, this cant be normal after every ride.

Forgot brakes are Avid Elixir 1s, Yes I know they are not the best and I will be upgrading to XTs within a month or 2.

Cant understand why after I clean the bike brake performance is gone until they bed in again.

Thank you for the help and reading :)

Mark

When I understand how to attach a picture I will :)

Posts

  • kajjalkajjal Posts: 3,380
    With disc brakes contaminating the rotors or pads means the braking gets severely impacted. Best to take both wheels off when cleaning and just use water to clean very dirty discs if you need to. I have the same brakes and they have been fine for me since in first adjusted them to my needs. Sometimes you just need to go down a steep hill and pull the brakes on hard all the way down to clean them up again.
  • micedenmiceden Posts: 225
    There are "disc friendly" bike cleaners, Hope's censored Shifter is good.

    Do you have this problem after cleaning on both the front and rear, or just one? Spraying anything on the bike, after cleaning,that could be contaminating the pads?
  • I know MUC Off is disc friendly. This is what is confusing me.

    The rear break only sounds noisy but still has bite, the front brake looses all bite.

    I don't spray anything on after, only water followed by muc off followed by water.

    The problem only happens after cleaning the bike. I try not to let anything contaminate the rotors, don't touch them etc.

    After a few miles the bite is back.

    Would say the problem is related to front only. I don't have any leaking fluids.

    Best way to describe it is, cleaning the bike removes the brakes surface, I don't scrub the brakes only spray water and muc off on to them.
  • cooldadcooldad Posts: 32,599
    Stop faffing with them. Hose them down if muddy and just leave them.
    Water (and Muc off) won't do any harm, so you are doing something else.

    Do you take the wheel off, perhaps open the pads in the process?
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  • Chunkers1980Chunkers1980 Posts: 8,035
    Put new pads in and don't clean them at all
  • Literally I spray the bike with water, then with muc off including the brakes then rinse off nothing more.

    Not faffing about, but when you grab the front at speed and feel next to nothing its worrying. No confidence etc, I dont scrub the brakes only spray.

    Could this be enough to take the bite off?

    Like I said after a few miles its good again.

    Eg, I clean on Friday, then ride on Monday and it takes a few miles for the front to bite, so they are dry etc.

    My new pads are 2 weeks old. Could it be worth giving them a light sand again?
  • [img][/img]DSC_0266_zps3d352d72.jpg
    [img][/img]DSC_0265_zps7c119137.jpg

    After one ride to show how dirty it gets. I have no choice but to clean, don't remove wheels etc, like I said only water muc off water. Nothing more.
  • oxocube1oxocube1 Posts: 651
    By the sounds of it you are getting build up of grime on your pads from the previous ride and the wash, then having to remove it via braking in the next ride, which in turn is the reason for the poor performance until that build up has gone a few miles in.

    I tend to remove and clean the pads from my brakes every 4-5 rides and twice as often as that, if not every ride in the winter. Here's what I do to prevent excessive pad wear and keep my brakes (XT M785) running as best as possible:

    - Clean the bike as normal with water and Muc off and then remove the pads from the calipers
    - Spray the calipers with disc brake cleaner and wipe down the outside, along with the pistons on the inside
    - I then spray db cleaner on the pads and wipe any mud/grime off them
    - Then use some mid grade wet/dry paper to lightly sand them so that they show a shine on the braking surface.
    - Clean them off with db cleaner once more to remove any dust/resin from the sanding
    - Finally put the pads back in the bike.

    I will usually clean the rotors with some db cleaner as well if they are particularly dirty.

    It will take a little longer to clean the bike but is definitely worth it for keeping your brakes in shape. The original pads that came with my brakes lasted 14 months and the rear and are still going on the front! Using this cleaning method definitely helped my pads last this long also helps maintain the quality of the brakes themselves.
  • JBAJBA Posts: 2,850
    Avid Elixir 1 brakes are denied for 160, 180 and 200 mm discs. It could be that be fitting a 183mm disc the front pads aren't contacting enough of the braking surface and aren't biting until they have warmed up a bit.
    Try fitting a 180mm disc and see if that improves things.
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  • JBA thanks :)

    Think you might have hit the nail. I just went on what my local bike shop passed me. Didn't really think about double checking size.

    Went out today without cleaning the bike and it was the same, a few miles before the front started biting.

    Im not in a very hilly area so I can't warm them up quicker.

    Might stick the 160 back on and see what happens. Then keep the new hope rotor for when I get XTs if the XT is compatible with a 183mm.
  • 02gf7402gf74 Posts: 1,168
    why are you wasting money with muc off? a tub of hot/warm water with a squirt of washing up liquid applied with a toilet brush or toothbrush for the crevices works for me - never had probles with brakes.
  • 02GF74 wrote:
    why are you wasting money with muc off? a tub of hot/warm water with a squirt of washing up liquid applied with a toilet brush or toothbrush for the crevices works for me - never had probles with brakes.

    Came free with a buy 3 things and get the cheapest free, also used it before with no problems and good results.
  • change the pads, re-clean the disc and they'll be fine! the PTFE has soaked into the pad material, no amount of sanding down etc will help that i'm afraid. They still have traces of PTFE on them. Get on uberbike, pay the £7ish for a new set and take it on the chin.
  • Ok tomorrow I will do a test.

    Will swap the rear pads for the fronts and clean the rotor then go for a short ride and see if its the pads.

    If still the same, will swap to the old rotor and ride again.

    Should clear up if the rotor is the wrong size or if the pads are contaminated.
  • you'll contaminate the rear then.....
  • Didn't think that far ahead.

    Will clean front rotor and put new pads in then try and see how I get on, hoping when I get new XTs within a month or 2 it should be trouble free.
  • This will solve your problem i'm 99% sure
  • JBA wrote:
    Avid Elixir 1 brakes are denied for 160, 180 and 200 mm discs. It could be that be fitting a 183mm disc the front pads aren't contacting enough of the braking surface and aren't biting until they have warmed up a bit.
    Try fitting a 180mm disc and see if that improves things.


    Avid calipers will work with whichever correct adapter you buy to suit the disc. The only issue that may occur is the caliper hitting the rivets on the hope disc. However this isn't the case
  • I will clean both the hope 183mm rotor and the avid 160mm rotor tomorrow then try the hope first then switch to the 160mm.

    Luckily I am on a trans pennine route. So this will eliminate rotor problems or should identify the pads being the problem.

    I only need a temp fix until upgrade time. But it takes the fun away not having confidence to go fast.
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