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New bike, disc brake question

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New bike, disc brake question


Old 03-22-15, 06:17 PM
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New bike, disc brake question

I just picked up a Trek Dual Sport with disc brakes. I was told I need to break them in by hard braking to scrape off the coating used for storage. Anyway the rotors rub a bit but not for the entire rotation. Also the wheels seem to drag a bit.

So is this something that will "wear in" or should I bring in for service?
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Old 03-22-15, 11:45 PM
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New pads need to be bedded in an burnished.

Burnish – Brake power is generated by the friction material on the pads embedding into the surface of the rotor, re-bonding to the friction material still on the pads and then breaking apart or shearing. In order for this bonding/shearing to occur, the friction material must first be displaced onto the surface of the rotor. This typically happens during the first 10 – 50 stops of a brake system and is referred to as “burnishing” the rotor and pads. When a rotor is cleaned, it will need to be re-burnished again to re-deposit the friction material onto the surface.

Rotor Truing: https://www.youtube.com/watch?v=0fosSuyiCDE
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Old 03-23-15, 07:36 AM
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You should not have any "drag" on a new disc brake system. The shop should adjust that out.
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Old 03-24-15, 06:47 AM
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Indeed ... I wouldn't expect drag on a new bike. Maybe take it back and get it looked at. Spin the wheel and look at the discs - check they are not bent.
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Old 03-24-15, 06:59 AM
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are they mechanical or hydro?
they shouldn't rub regardless, have the shop check them out
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