Deore brakes currently with Uberbike sintered pads.

Where I live is relatively flat, I only weigh 12stone.

Pads don’t seem to have much ‘bite’ and I’m wondering if they are glazing over because they don’t get hot enough?

I have tried sanding the pads, cleaning the discs, bleeding with new fluid.

The pads have little initial bite and then become very noisy/sqwuarky the harder I squeeze the lever.

I had the same with some sintered pads from Superstar (but TBH they probably come from the same factory as Uberbike)

These are Deore brakes that are nearly 4 years old, and ever since a Dartmoor trip last year where I did get them hot – I know this because I burnt my leg on a disc – they haven’t been the same since.

They have been bled twice since I got them hot.

Try some shimano pads, maybe resin ones

I know it sounds daft, but just find a vaguely slopey bit, pedal yer ass off and brake hard, one brake at a time.
Do it a good few times ’till you can feel the difference.

You don’t need a huge hill or to be going really fast, it just saves time.
🙂

Try some shimano pads, maybe resin ones

+1

If you are using larger rotors try going down to 160s

To be honest I tend to use sintered in the winter where they are more wear resistant. When its drier I use organic pads as they provide pretty good power.

They are Shimano brakes. The seals have gone and they are spraying atomised brake oil on the discs every time you pull the levers. They are not serviceable, so you need to buy new calipers at the least. Or get a new set of brakes (Hope are good) that don’t exhibit this problem and are serviceable as well.

Uberbike are noisier than Shims.

Nikk that’s an interesting hypothesis head anyone else had that problem?

Nick – I have wondered that. I have two sets of Shimano brakes, one of which got overcooked, which after a couple of rides loose most of thier bite and power. They are resurrected by popping rotor and pads in oven – but give up again a couple of rides later.
I have given up with the, and bought new brakes.

While nikks suggestion is a possibility, there are other reasons this might be happening. I used to experience the same problem commuting around Edinburgh, and that was with cable brakes.

Can a bad bleed cause this? Mine were mostly fine till I bled them and have been terrible since. Removed pads and wheels prior to bleeding so defo no contamination during bleed. Very possible I bled them badly as had never attempted previously.

I am competent at bleeding brakes – and both sets have been really fussy and done full replacement fluid bleed, twice. Still no power. Mine are really firm to squeeze.

As scotroutes suggests, it could be road contaminants, or as I think I have also had, car exhaust on rear tow bar rack.

Having said that, I chucked new brakes on in a hurry last night on ‘old’ rotor – and they are mega powerful and bite sharply.

Thanks all. The theory of some contamination may be valid, as they seem OK for half a ride after cleaning the discs, then lose bite.

Given their age I may bite the bullet and get some new Deores

If the lever is spongy and it becomes firmer when you pump the lever then there is air in the system and they need a bleed. If the lever is firm then a bleed won’t help, it’s purely lack of friction between the pads and the rotor.

If you put new pads in and they are better but deteriorate quickly then chances are the caliper seals have gone and you need a new caliper. If new pads achieves nothing then the contamination is on the rotor.

My money is on caliper seal failure.

I’ve had the same problem with Deore’s on a flat commute, pads would glaze after a week or so. Found it took longer with some lightweight rotors and organic (Superstar) pads as they worked the surface of the pads harder. Still got glazing after a while but nowhere near as bad as before.

Now using a v-braked bike on the same commute after the old one got accosted by a taxi, more than powerful enough for general duties in the wet. Discs aren’t always best.

Given my recent experiences with 2 sets of 4 year old XTs. My money is on the failed calliper seal theory. It can be infuriating.

So tiny, it was virtually impossible to spot. The only way I did see it was to leave one of the bikes standing with a film of dry dust whilst I used the other one, and there was a small tideline of discoloured oil on the calliper.

These days if I get your symptoms and it remains after a couple of disk cleans and a pad swap, I just change the calliper.

take pads off and give them a little sanding,then give the discs a clean in fairy and then sand the disc. rinse with water and dry. refit it all then bed the pads in again (properly?)

I am telling you, it is the seals 😀

Exactly this.

Shimano brakes are no good once they are past their 1 / 2 year new threshold. Literately throw them out and buy a new set time.

Me and a load of other people have spent months chasing our tails sanding pads / cleaning rotors / changing pads / bleeding systems. There are a bunch of threads about it on here.

IMO the brakes are not fit for purpose, but I am kinda evangelical about it. They are ok if you change bikes every couple of years 😆

IMO the brakes are not fit for purpose, but I am kinda evangelical about it.

You’re being evangelical about something as it’s a matter of belief rather than evidence?

It’ll be your pads. Chuck away the silly sintered ones and stick in some resin pads and bed them in properly you don’t need a hill, just accelerate hard and brake hard 10-15 times. Get the brakes bled properly, and then leave them alone, Brakes don’t need to be bled every couple of years.

Never needed to bed in rahox pads.

I never got on with the Uberbike sintered pads in my slx brakes. They squeeled really badly and I had a worrying amount of rotor wear. Sticking to the Shimano pads now.

I can believe the caliper seal theory as i’ve had similar experiences with shimano m615 deores. I’ve changed pads and rotors but not at the same time, blow torched pads, sanded discs etc and nothing seems to work.

If I ride down the steepest hill in the area with the brakes jammed on and still pedalling hard they will start working again but the next time I go to the bike its terrible again. Theres also black contamination on the discs.

I never got on with the Uberbike sintered pads in my slx brakes. They squeeled really badly and I had a worrying amount of rotor wear.

should have sanded your discs to remove any previous pad residue first – what rotors did you have, some shimano discs are resin only so wear a lot quicker with sintered pads

Brakes don’t need to be bled every couple of years

AFAIK, that’s the total opposite of what should be done for shimano. Madison said some stuff about this somewhere a couple of years ago. Might even have been on here.

Given the utter shiite that comes out of a shimano lever after six months, I think they DO need regular bleeding.

Old advice used to be to squirt water over new brake pads while riding along applying them – is that still a thing?

It can certainly help clean the old residue off the discs / pads.