Chinertown

Chinese Carbon MTB => 29er => Topic started by: blueducati on June 23, 2015, 08:23:19 AM

Title: 256 Brake Post Facing
Post by: blueducati on June 23, 2015, 08:23:19 AM

Has anyone had to have their 256 rear brake posts re-faced? I've been struggling with a weak and dragging rear brake since the beginning. I always thought it had to do with the fact that I had to cut the rear hose and re-bleed. After a dozen rear-bleed attempts and a month at a LBS (not my usual one, I tried to save the hour drive), it's still happening. I finally got a hold of someone at Magura and without hesitation, he said I probably need to have my rear brake tabs re-faced. The bike shop opens in a half hour, so I will call to see if they can do it, I just figured I'd ask here to see if anyone had to do the same.

Title: Re: 256 Brake Post Facing
Post by: carbonazza on June 23, 2015, 09:41:25 AM

You should see this on the wear of the brake pad.
If the wear is regular and parallel to the metal part, it is correctly faced.

Title: Re: 256 Brake Post Facing
Post by: blueducati on June 23, 2015, 11:12:44 AM

My calipers are 4 piston, and I noticed the the front two pads (one on either side) don't even touch the rotor.

Title: Re: 256 Brake Post Facing
Post by: carbonazza on June 23, 2015, 03:01:30 PM

Isn't it a problem with the two front pistons not going out as far as they should?
You can check the wear on the disc too.

Title: Re: 256 Brake Post Facing
Post by: blueducati on July 05, 2015, 04:33:09 PM

Just to follow up on this. I got my bike back from the shop a few days ago, they re-faced the caliper mount posts. That was definitely the issue I've been having since the very beginning. The rear brakes are now as strong as the fronts. So if you have a 256 and are having weak or dragging rear brakes, might want to check that out.

Title: Re: 256 Brake Post Facing
Post by: Vipassana on July 06, 2015, 04:58:39 PM

Good to hear about the resolution.  How did they face them?

Title: Re: 256 Brake Post Facing
Post by: blueducati on July 07, 2015, 02:37:59 PM

There is a specific facing tool (by Park). I think it's a $300 tool. Anyway, from what I can tell, the tool mounts in place of your rear axle, and then the cutting portion of the tool is held parallel to that, so you know you are cutting parallel to the axle, and thus perpendicular to the rotor.

Title: Re: 256 Brake Post Facing
Post by: RS VR6 on July 07, 2015, 02:50:45 PM

Pretty cool! I had no idea a tool like that existed...and I worked at a bike shop.

Title: Re: 256 Brake Post Facing
Post by: blueducati on July 07, 2015, 03:02:02 PM

I think this is the tool.

http://www.jensonusa.com/!EQd8z3bmNIWiPWV8ZmXAgQ!/Park-Tool-Disc-Brake-Mount-Facing-Tool?utm_source=FRGL&utm_medium=organic&gclid=CJfHxevnycYCFYIXHwodqZ0I3w

Title: Re: 256 Brake Post Facing
Post by: RS VR6 on July 07, 2015, 07:08:27 PM

Very handy tool for a shop to have around.  :)