Front brake rotor warped By couchman420 (Read 1,723 times)

[couchman420]

I noticed my front brake rotor on my scooter is warped; not severely, but enough that the rotor scrapes against the brake pad(s) when the brake is not applied. The rotor has begun to discolor (is that the right term?) from the constant scraping, the way a piece of metal would if you held a flame to it.

I would like to know if there is a way to adjust the front brakes or possibly (but unlikely) un-warp the brake rotor?

Many thanks in advance.

[sprocket]

The pads on these scooters 'float'.. You might try shimming the rotor or the caliper, but it probably best just to replace it.. they are fairly cheap...

[Bashan]

The rotors on my Bashans warped almost immediately after we first rode them but haven't got any worse over three years. The rotors on my CF Motos are perfect as is the one on my Motorino (Znen). I'm assuming it has to do with the metal quality so possibly you could replace them with better made rotors. The allen bolts that hold them on are supposed to come out easily but several guys on the forum have had a time with them. You can't straighten them out once they warp. The banner vendors at the top of the site that sell parts are all great guys and I'm sure they could direct you to high quality rotors. Rich

[couchman420]

Mar 18, 2012 13:54:06 GMT -6 Bashan said:

...The allen bolts that hold them on are supposed to come out easily but several guys on the forum have had a time with them...

If worst comes to worst and I can't get the bolts out, how should I go about replacing the rotor?

[sprocket]

I have used an Allen key in an impact wrench...on the stubborn ones...it is like an Allen key in a socket...I think I bought them at Loews

[roketafan]

Be sure to get the mm ones or they will strip if u use standerd ones

[silverfox96]

I've always been under the impression that with all disk brakes, the pads are in contact the rotor at all times. Not true of shoe brakes, though.

[couchman420]

Mar 20, 2012 7:41:51 GMT -6 silverfox96 said:

I've always been under the impression that with all disk brakes, the pads are in contact the rotor at all times. Not true of shoe brakes, though.

Going back to my days in HS automotive service class (my favorite class!) I remember that the piston inside of the caliper has a rubber ring attached to the outside of the piston. There is a groove in the caliper that the rubber ring fits into and holds the piston in place, not touching the rotor until you apply the brakes, then when you release them, the rubber ring pulls the piston back into the caliper.

I'm not sure if this is true on scooter calipers, though.

[roketafan]

Works the same

[couchman420]

Well, I finally got around to taking the front brake caliper off to see if there was anything I could do to remedy the situation.

It looks as if the rotor wasn't just warped and rubbing against the pads, the side of the rotor was rubbing against the pins that were holding the brake pads in place.




Here's a little video showing warping and out-of-round:


And to top it off, one of the pins the caliper slides on was barely in place. There was a good 4-6mm of threads showing.



I got it all tightened up and threadlocked. Hopefully that will help once I get my new rotor.

[roketafan]

nice pics looks like your on the right track

[jct842]

Looks to me the rotor mounts are wrong. it is running out of round and it might not be warped but might be the mounting it self. Before your buy a rotor do some more checking. I would check the centers of the mounting bolts first and the surface of the wheel where it flats up against. also the wheel bearings.

[couchman420]

Mar 22, 2012 20:44:48 GMT -6 jct842 said:

Looks to me the rotor mounts are wrong. it is running out of round and it might not be warped but might be the mounting it self. Before your buy a rotor do some more checking. I would check the centers of the mounting bolts first and the surface of the wheel where it flats up against. also the wheel bearings.

It looks that way because I took the pic with the caliper slide not threaded in all the way to show how bad it was. I could move it about 5mm side-to-side. Once I tightened it up, everything lined right up. I also checked the wheel bearing - all good.

I did notice an unfortunate problem not unrelated to this; somehow my brake line has been rubbing against my wheel and now I have to buy a new line. What I need to know is are the banjo fittings on these scooters the same as on cars? In other words; can I take my brake line into an auto-parts store and buy a new one the same (or close to the same) length?

[roketafan]

just have to take your line to the auto store and see if you can match one up