I just noticed that the rear rotor on my son's 90 ETON Viper is loose. Can't find anything on the web or in the manual on what to do to tighten it. Anyone have any insight? If I grab the rotor I can move it forward and back maybe 1/8" each way. When he rides you can hear it "ping". Want to get it straightened out before it gets any worse. Any help would be appreciated.

Edited to add - The actual rear rotor mount that the rotor attaches to is what is moving.

 

Is it the axel hub wore or the axel splines?

 

I guess that's the real question to ask. I didn't realize that the rotor mount plate had grooves to fit like a gear. The play in the rotor is forward and back, not side to side so seems like something is for sure wearing out. I guess I need to take it off to see what the real deal is.

 

Not sure if that is a wheel hub Jack, justcallmejoe refers to brake rotor?, Some bikes (Honda Rincon for example) have sliding discs instead of sliding calipers on the brakes, if it is that type, the disc hub is supposed to slide, but the brake piston is supposed to only move about 1mm back when the brakes are off, which keeps it from moving far.

 

Pictures below. The rotor (or disc) bolts up to the rotor mount. The rotor mount and rotor both move forward and back a little bit. 1/8" at most. There is no movement side to side (or left wheel to right wheel). So I know that the rotor is tight to the rotor mount but the rotor mount itself seems to be loose. If you look at my original post about I added a photos of a rotor mount and you can see it has splines. This makes me think either the rotor mount splines are getting worn or whatever part the rotor mount mates up to is getting worn.

 

OOOPSIE. lol

 

Well, it is sliding caliper, so that disc hub is supposed to be held tight by the big narrow nuts in the picture. One thing about brakes is they take all the thrust one way (except if you are reversing) so worn brake splines are less likely than hubs to come loose again once you get those nuts tight.

 

I'm going to dig into this today and see what I can find. Haven't had the chance to take it apart yet. I do know those narrow nuts that look to hold the rotor mount in place seem tight but again, maybe not. I haven't really gotten into it yet. I'll post back what I find. That's for the help so far.

 

The rotor mount fix was simple. Just tightened the 2 nuts to the left of the rotor mount and problem solved. This didn't clear up the noise that i'm hearing though. I found that if I rock the ATV left and right I get this creaking noise. As in I push down on the left handlebar then on the right. Sounds like the frame is moving around a little. Started pouring out so we stopped messing with it for the day.

Any ideas on why the frame is making noises? I did a quick look over and didn't see any noticeable cracks in the frame. .

 

dry/worn bushings