ElectricMotorcycleForum.com

Makes And Models => Zero Motorcycles Forum | 2013+ => Topic started by: heroto on December 08, 2018, 10:52:47 AM

Title: Zero S front rotor warp
Post by: heroto on December 08, 2018, 10:52:47 AM
2018 S 7.2, purchased last Feb. When brand new, the front brake had a bit of tick tick tick when braking hard but tolerable. It got worse during the first 2k, clearly a warped rotor after 1 k and progressed to plus minus unsafe at 2k. Zero to their credit just replaced it under warrantee.

First ride after the warrantee replacement: The brand new rotor has the same tick tick tick that the bike had when brand new. I will give it some time, but for sure I've heard this music before.

I know how to ride without damaging and warping rotors. It's not the pilot this time.

And maybe it's not the rotor. Perhaps a small flaw in the front wheel rotor mounts that deform the front rotor, which causes subtle uneven braking when new (tolerable, like now), and leads to warping over time? Front brake rotors are cheap, and if I had to mount a new every year I could live with that. But the wheels, not so much.

Thanks, any advice appreciated.

Title: Re: Zero S front rotor warp
Post by: Richard230 on December 08, 2018, 08:43:51 PM
I would try replacing the brake pads with an aftermarket brand and see if that helps.  I have had a number of "pulsing" front brake systems over the years and none of them seem to have been the result of actual, measurable, warping of the rotor.  Instead it appears to be the result of uneven transfer of material from the pad to the surface of the rotor.  I have tried sanding the surface of the disc and then cleaning it thoroughly with denatured alcohol, and that will help for a while, but the problem always seemed to return until I replaced the rotor with a new one.  Doing that and changing brake pad manufacturers at the same time will usually permanently solve the "pulsing", at least it has for me.

However, a "tick, tick, tick" noise when braking could be caused by loose steering bearings, so be sure to check those.  In my experience, Zero does not always set up the tension of their steering bearings correctly at the factory, although most of the time they seem to be too tight.
Title: Re: Zero S front rotor warp
Post by: ESokoloff on December 09, 2018, 07:59:11 AM
Per chance do you have/have access to a dial indicator?

If your interested in checking rotor runout & don't have one, you can pick them up (along with a base) fairly cheep.

I found the rear sheave/sprocket on my 16 DSR to have substantial runout that caused a 5-10nm difference in belt tension. Hollywood Electric replaced via warranty :D
Title: Re: Zero S front rotor warp
Post by: heroto on December 09, 2018, 08:16:20 AM
Hi Richard, sorry I wasn't clear. The "tick tick tick" is feedback from the brake lever. Feel, but not like an obviously warped rotor. At least with the earplugs in, it's not a sound that I can perceive.
Title: Re: Zero S front rotor warp
Post by: Richard230 on December 09, 2018, 07:42:26 PM
Hi Richard, sorry I wasn't clear. The "tick tick tick" is feedback from the brake lever. Feel, but not like an obviously warped rotor. At least with the earplugs in, it's not a sound that I can perceive.

I am not sure what to make of that.  You will need to have an experienced mechanic ride your bike to listen and feel the "tick".  I don't think the internet is going to be of much help.   :(