Post by ryanqzqz on Sept 23, 2019 20:18:08 GMT -5
I know, a question about another vibration... but I'm VERY familiar with tires in the automotive world, not necessarily the two-wheel world. So I don't want to assume all is the same in love and war here. Fair warning, this issue DID NOT occur, until I layed the scoot down after pulling the front wheel off the ground at a stop light. (Don't ask. Broke a CVT belt, replaced it, first stop light, pulled a small wheelie... was not expecting that. Was expecting, pull throttle, wait for go; still not sure I wasn't hallucinating.) It broke the shield off the exhaust, broke off a passenger peg, and scuffed some plastics up and moved a few edges around.
Scoot has about 1k miles, tires still in great shape, few upgrades. Runs well. At EXACTLY 40-41mph (these are all speedo indicated speeds). I get a vibration felt, and heard. Felt through the frame and entire scoot like a motor buzz, or one of those chintzy massage chairs at the mall. Heard like someone put a coffee can on top of a phone, placed a coke can inside, and made the phone vibrate nonstop. It buzzes up the front fork and shakes the plastic on the speedo pretty bad too.
The noise is louder than my exhaust.
The vibration can be felt building from 35mph up to the 40mph threshold, as soon as the scoot is over 41mph, it fades VERY quickly.
The noise is ONLY at 40-41mph. I can hold speed there on a flat, and it all stays steady. I can let off the throttle and it goes away and vibration slowly fades to 35mph. If I'm doing 45mph downhill, and brake, as soon as the scoot passes through those speeds, it makes the noise and vibrates, even when I'm off the throttle. I can coast down from 45, so I know RPMS are already lower than normal, tap the brakes at 43, and WHAMMO, right at 41mph, coffee can noises.
For those reasons, it doesn't seem RPM related (also because on acceleration, when RPMS jump up off the line, I don't feel or hear it)
Because of THAT, I think it's a wheel balance problem. I HAVE NOT BALANCED THE WHEELS (I know, you're gonna tell me to. I really should anyways, just for reasons) My concern is overlooking other, less familiar to me issues.
I pulled the front wheel, and checked the bearing for any funny feeling, and re-greased it, checked the speedo cable/fitting, and greased it. Greased the speedo cable, and checked where the speedo cable plugs into the speedometer. No issues I could see. Re-torqued and drove, still there. Took apart front pads and put all back together. Same thing.
Found loose baffles etc inside the exhaust, cut the hotdog apart, pulled the offending pieces out, re-welded with a 1" diameter hole in middle of hotdog rear end, and welded a 2 inch turndown end on. No more exhaust rattle, vibration/noise still there.
New clutch, new belt, net variator, same noise. I've even pulled every tool and item out of the scoot to make sure it wasn't just something rattling. Same noise.
This Thursday when I'm off work, I plan to balance wheels. What else should I check?
Scoot has about 1k miles, tires still in great shape, few upgrades. Runs well. At EXACTLY 40-41mph (these are all speedo indicated speeds). I get a vibration felt, and heard. Felt through the frame and entire scoot like a motor buzz, or one of those chintzy massage chairs at the mall. Heard like someone put a coffee can on top of a phone, placed a coke can inside, and made the phone vibrate nonstop. It buzzes up the front fork and shakes the plastic on the speedo pretty bad too.
The noise is louder than my exhaust.
The vibration can be felt building from 35mph up to the 40mph threshold, as soon as the scoot is over 41mph, it fades VERY quickly.
The noise is ONLY at 40-41mph. I can hold speed there on a flat, and it all stays steady. I can let off the throttle and it goes away and vibration slowly fades to 35mph. If I'm doing 45mph downhill, and brake, as soon as the scoot passes through those speeds, it makes the noise and vibrates, even when I'm off the throttle. I can coast down from 45, so I know RPMS are already lower than normal, tap the brakes at 43, and WHAMMO, right at 41mph, coffee can noises.
For those reasons, it doesn't seem RPM related (also because on acceleration, when RPMS jump up off the line, I don't feel or hear it)
Because of THAT, I think it's a wheel balance problem. I HAVE NOT BALANCED THE WHEELS (I know, you're gonna tell me to. I really should anyways, just for reasons) My concern is overlooking other, less familiar to me issues.
I pulled the front wheel, and checked the bearing for any funny feeling, and re-greased it, checked the speedo cable/fitting, and greased it. Greased the speedo cable, and checked where the speedo cable plugs into the speedometer. No issues I could see. Re-torqued and drove, still there. Took apart front pads and put all back together. Same thing.
Found loose baffles etc inside the exhaust, cut the hotdog apart, pulled the offending pieces out, re-welded with a 1" diameter hole in middle of hotdog rear end, and welded a 2 inch turndown end on. No more exhaust rattle, vibration/noise still there.
New clutch, new belt, net variator, same noise. I've even pulled every tool and item out of the scoot to make sure it wasn't just something rattling. Same noise.
This Thursday when I'm off work, I plan to balance wheels. What else should I check?
