New 700 Series ST has "massive" vibration between 14-17 mph and then goes away

[doeweb]

My wife (has 700 ST) and I (Limited) took our new bikes out for our first long journey. She didn't say anything but when I was on hers going back and forth, I could feel a great deal of vibration that could be felt pretty bad on the seat. I feel like it's coming from the rear hub but I'm not sure. Pedal or Throttle and it only appears at around speeds between 14-17 mph. Then it goes away. Has anyone experienced this? I don't feel that all on my limited.

 

[Limeybastard]

I feel a somewhat constant rumble noise, when applying throttle , in lay terms I would say it doesnt sound smooth perhaps?

 

[Marrduk24]

I have the same issue.

 

[theemartymac]

If it's truly a significant vibration, first I'd check the exterior for physical problems or assembly issues. Loose/broken spokes, cracked/bent/warped rims, warped/loose brake rotors, reasonable tire pressure, etc. Suspend the bike and see if the wheel has a reasonable balance (turn 45 degrees, see if it settles quickly to fixed point - try again and again from different starting points to see if there is a common and obvious heavy spot.) If you can't find anything obvious, some other troubleshooting to determine if you can tie it specifically to throttle input, pedal input, PAS levels, specific gears, etc. It's under warranty, so once you have some better details, contact your dealer or Ride1up.

I've read several references to hall sensors or shorted/broken 3-phase wires being a potential cause of hub vibration, as well as pinched harnesses, but it really could be a bunch of things. If it's still on warranty, don't mess too deep. A cheap hub motor tester off amazon would let you test the internals without removing it, but you shouldn't have to go buying diagnostic tools for a new bike just yet. Use your warranty before it's too late.

 

[Marrduk24]

If it's truly a significant vibration, first I'd check the exterior for physical problems or assembly issues. Loose/broken spokes, cracked/bent/warped rims, warped/loose brake rotors, reasonable tire pressure, etc. Suspend the bike and see if the wheel has a reasonable balance (turn 45 degrees, see if it settles quickly to fixed point - try again and again from different starting points to see if there is a common and obvious heavy spot.) If you can't find anything obvious, some other troubleshooting to determine if you can tie it specifically to throttle input, pedal input, PAS levels, specific gears, etc. It's under warranty, so once you have some better details, contact your dealer or Ride1up.

I've read several references to hall sensors or shorted/broken 3-phase wires being a potential cause of hub vibration, as well as pinched harnesses, but it really could be a bunch of things. If it's still on warranty, don't mess too deep. A cheap hub motor tester off amazon would let you test the internals without removing it, but you shouldn't have to go buying diagnostic tools for a new bike just yet. Use your warranty before it's too late.

Well it is unlikely to be anything exterior. I got the bike only this week and had a trusted LBS build it.
Also the issue happens only when the motor is kicking on and trying to thrust the bike to speed (roughly between 10-18 mph) and disappears once the bike is above 18 mph or so. So I am 99% sure it is motor vibration.

 

[GenXrider]

I've seen a feedback from various users reporting vibration on the 700.

I haven't noticed much vibration on my 700 XR. I don't normally use much PAS or throttle, but I did do some throttle-only riding today for test purposes going from low speed to 28 mph riding several miles up and down small hills and never noticed any unusual sound or vibration. There might be a little at times, but that's to be expected with these motors.

 

[PedalUma]

Confirm that the back wheel is aligned. A back wheel that is not straight in the dropouts or a slightly misaligned rear triangle will do this. If it is the frame that is warrantee.

 

[ki11a]

It sounds like the motor is reverberating with the frame at that specific RPM, because of the symptoms described, if avoiding those power ranges of 10-18mph it will alleviate itself.

My XP does the same thing around those speeds, the motor/spokes/rim/frame will make sort of a humming noise.