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Where Has My Friction Gone?


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I've recently found a problem with lack of braking power on the front of my Electric Motion. First, a little bit of background: I've had the bike for three years and this problem has just started. The front brake is a braktec monobloc. My normal procedure between trials is to abrade both pads and disc with wet'n'dry and clean with brake cleaner.

Three trials ago I fitted new Galfer red pads. For the first trial they worked fine. At both of the next two I found that the braking power was very weak. Although it was something I had never done before, and was a bit sceptical about, I rode up and down a bit with the front brake on to heat it up, then sprayed it with water. It was hot enough to hiss and generate quite a lot of steam. Thankfully this procedure seemed to get the brake working adequately but it's going to be a bit of a pain if I have to do that every trial.

Does anyone have any thoughts? Just to confirm, the hydraulics have not been disturbed and the lever feels just as firm as ever. If I don't find any other solution I think I will put back the old pads for the next trial and see if they are any better.

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Possibilities:

Most Trials riders use Galfer Red pads:  GALFER RED TRIALS BIKE FRONT BRAKE PADS. BETA, GAS GAS, SHERCO, MONTESA, SCORPA. | eBay

3 year old bike?  I assume the brake fluid has been replaced recently?

1.  Weeping brake piston seals.  Have you lost any brake fluid from the brake reservoir?

2.  Weeping fork seals.  The oil will run down the fork leg and contaminate the brake disc. It may be hard to see without close inspection. 

a: Try cleaning the fork seal using a Seal Mate tool.

b: New fork seals.

3.  You have somehow contaminated the disc with WD40, polish, grease etc.

 

 

Edited by stpauls
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hi IMHO could be two things as you say fluid is good /  lever feel is solid 

 1  id be looking towards a replace the  front disk/rota  (on a 3yr old bike) the disc always gets over looked but it wears as well  the disc will have wear limit printed on it  but take a good look at the surface of disc  

2 are the pads binding in the calliper  

just a thought.. whats front wheel bearings like and is disc straight  both could push pads away from disc 

 

 

 

 

 

 

 

 

 

 

 

Edited by on it
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I fitted Galfer pads to the missus' Evo (having read on here how good they are).  I did not notice any improvement.  I fitted a Galfer disc and the brakes worked (unusual for a Beta 😁)   I also replaced the M/C with a Braktec (as per the factory bike).  The bike was improved by a huge amount and once the pads bedded in it was as good as my TRS.

Sadly the missus wanted an EM so the Evo got sold off for the E-Pure.  I have wondered if the Galfer pads are really all they are cracked up to be?

My TRS took a while to bed in and the brakes at first were not as good as the old 2017 I traded in for it (new one is '23).  Couple of mates had a go on the new bike and also commented that the brakes were not as good as they expected.  Now it locks up with little effort on a single finger pull.  I assume they are the OE pads.  Like you I am uncofortable with the 'heat them up and boil them' idea....

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Between every trial you do that?! Usually after a power wash and dry my brake is as good as it was at the start of the trial, and if it isnt i go straight to the dousing with cold water.

I would almost certainly say its the brake cleaner you are using. Is it general automotive stuff? Ive never cleaned a brake with that and it hasnt been crap after. I think its grand for car use where theres loads of oil and brake fluid around and then followed up with lots of heat to burn whatever residue it leaves behind off, but its never left a good sharp brake on my motorbike or mountainbike. Even rubbing your fingers across it afterwards it feels slightly slippery. You would probably be better just using pure IPA

Edited by faussy
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7 hours ago, faussy said:

Between every trial you do that?! Usually after a power wash and dry my brake is as good as it was at the start of the trial, and if it isnt i go straight to the dousing with cold water.

I would almost certainly say its the brake cleaner you are using. Is it general automotive stuff? Ive never cleaned a brake with that and it hasnt been crap after. I think its grand for car use where theres loads of oil and brake fluid around and then followed up with lots of heat to burn whatever residue it leaves behind off, but its never left a good sharp brake on my motorbike or mountainbike. Even rubbing your fingers across it afterwards it feels slightly slippery. You would probably be better just using pure IPA

Yes, every trial. It's something I've done ever since I raced cars and karts as they were very prone to glazing when burbling back to the paddock with hot brakes. I've continued the procedure with the trials bike because I always find a film of dried mud on the face of the pads.

It's interesting that you would point your finger at the brake cleaner. The can is nearly empty so it has been used successfully quite a few times and the problem has only appeared at the last two trials. I've just re-prepped the bike and put the old pads back in so I'll see what they are like. Before the weekend I'll also have a sneaky ride down the road to check the brake beforehand.

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I just sand them dry and put them on dry to break them in.  One thing I did run across recently was wedge shaped pads, one end contacted before the other.  I had to keep sanding the high side until the pad face was parallel to the steel backing plate.  Might want to watch for that, they performed poorly out of the package.

Bought a set of pads with lots of brass flakes in them, those were garbage and I went back to Galfer reds.

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I guess you have never used the water trick. Which is the best way to get your brakes working in just a few minutes. Just over heat your rotors and hit them with a bucket of water. Instant sharp brakes.

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10 hours ago, lineaway said:

I guess you have never used the water trick. Which is the best way to get your brakes working in just a few minutes. Just over heat your rotors and hit them with a bucket of water. Instant sharp brakes.

Blow torch or do you do this on pavement?

Edited by lemur
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You just ride around a few minutes with that brake locked on almost skidding. Almost ends up like a steam clean.

 First time I ever say it done was Tommi Avala came to do a trials school/demo. Pulled a new bike out of a crate and FIXED the brakes in a few minutes.

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The first time I used the steam cleaning trick was with the bike running on a stand while strapped to the trailer.  It was the rear, and I just applied brake pressure while the wheel was turning.  I could easily monitor the rotor temperature with an IR thermometer (which is totally unnecessary).  Get the rotor so hot you can smell the pads cooking.  More than one application may be helpful.

Edited by konrad
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Easy to cook a rear brake by dragging it against the engine power, front brake not so much if you don't have pavement.  Last time I had a trials bike front brake steaming hot on trials terrain was never.

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