Radrover 2018 Peculiar Issue

S

SteveC

New Member
This is my first post as a very proud owner of my first e-bike...Radrover.

Here's a peculiar issue that, if anyone can help diagnose, I'd be much obliged.

The Issue: When pedaling or coasting in any gear at any PAS, I hear a vibration coming mid-bike ONLY WHEN THE MPH IS 14.8 TO 15.7. When the MPH is BELOW 14.8 OR HIGHER THAN 15.7....NO Vibration noise. The vibration noise sounds like something rubbing on chain ring....but nothing looks out of alignment and no sign of a rub.

Few more clues:

When bike is suspended, the vibration noise can't be reproduced.
All fasteners and bolts have been checked-all solid....pedals too. Nothing appears loose.
Definitely not coming from rear hub.
Breaks and gears work excellent too (alignment & spacing looks great)
RadpowerBikes is requesting a video...which I'll try to produce.

Any thoughts would be greatly appreciated.

Thanks!!

SteveC
 
Hey, Steve! Congrats on your Rad purchase! This sounds like a similar issue but unsure if it was solved. Hopefully Rad Bikes can help you once they see your video.
 
SteveC said:
This is my first post as a very proud owner of my first e-bike...Radrover.

Here's a peculiar issue that, if anyone can help diagnose, I'd be much obliged.

The Issue: When pedaling or coasting in any gear at any PAS, I hear a vibration coming mid-bike ONLY WHEN THE MPH IS 14.8 TO 15.7. When the MPH is BELOW 14.8 OR HIGHER THAN 15.7....NO Vibration noise. The vibration noise sounds like something rubbing on chain ring....but nothing looks out of alignment and no sign of a rub.

Few more clues:

When bike is suspended, the vibration noise can't be reproduced.
All fasteners and bolts have been checked-all solid....pedals too. Nothing appears loose.
Definitely not coming from rear hub.
Breaks and gears work excellent too (alignment & spacing looks great)
RadpowerBikes is requesting a video...which I'll try to produce.

Any thoughts would be greatly appreciated.

Thanks!!

SteveC
Click to expand...

Sounds like the issue I've been experiencing.

I noticed this noise the first day I had the bike and took it back to Rad in Seattle and they said it was motor noise and it was normal that some of the motors were noisier than others however it still sounds like the brake rotor or something similar is vibrating/ringing around 15mph, not the motor, and it's annoying. (Our Step Thru is quiet by comparison)

I've been riding with a trailer lately, going under 15mph, and I've almost forgot about it.
Seems to be rear brake related or perhaps loose spokes as this is the area the noise seems to come from.
Also, it seems to happen while coasting and goes away with rear brake application however since the brake quickly slows down the bike (below 15mph) and with the wind noise at 15mph, it's difficult to diagnose.
My best guess so far is tire tread vibration around 15mph is causing the rear brake rotor to resonate...perhaps changing tire pressure will give more clues? (currently at ~20psi and ~250 miles). Then again, maybe it's a motor bearing? and in that case I'd like it replaced.
 
I traced a noise issue, that would occur only with my (rather significant) weight on it, to loose spokes. Afraid I would pull the rim out of alignment, I very carefully tightened every spoke 1 turn, going around the rim twice turning 1/2 turn each time. Noise disappeared, rim still straight, life goes on......
 
Rover1701 said:
Sounds like the issue I've been experiencing.

I noticed this noise the first day I had the bike and took it back to Rad in Seattle and they said it was motor noise and it was normal that some of the motors were noisier than others however it still sounds like the brake rotor or something similar is vibrating/ringing around 15mph, not the motor, and it's annoying. (Our Step Thru is quiet by comparison)

I've been riding with a trailer lately, going under 15mph, and I've almost forgot about it.
Seems to be rear brake related or perhaps loose spokes as this is the area the noise seems to come from.
Also, it seems to happen while coasting and goes away with rear brake application however since the brake quickly slows down the bike (below 15mph) and with the wind noise at 15mph, it's difficult to diagnose.
My best guess so far is tire tread vibration around 15mph is causing the rear brake rotor to resonate...perhaps changing tire pressure will give more clues? (currently at ~20psi and ~250 miles). Then again, maybe it's a motor bearing? and in that case I'd like it replaced.
Click to expand...
Rover1701....great suggestions. I’ll follow up and let you know. Thanks. Given vibration noise happens with motor off...think that eliminates Hub/bearing issue?
 
AHicks said:
I traced a noise issue, that would occur only with my (rather significant) weight on it, to loose spokes. Afraid I would pull the rim out of alignment, I very carefully tightened every spoke 1 turn, going around the rim twice turning 1/2 turn each time. Noise disappeared, rim still straight, life goes on......
Click to expand...
AHicks...spokes appear tight, but I’ll do as you suggest. Thanks.
 
SteveC said:
Rover1701....great suggestions. I’ll follow up and let you know. Thanks. Given vibration noise happens with motor off...think that eliminates Hub/bearing issue?
Click to expand...
I originally thought so too however I believe the main motor hub bearings are still turning while coasting, since the hub motor is an integral part of the wheel, so perhaps they are the cause. Having the same speed relationship to the noise is also interesting; if it's the same for both our bikes, perhaps the cause is the same like a hub motor manufacturing defect the shows up in a small percentage of bikes? Loose spokes could also be the cause however I see a lot of reports of loose spokes causing different sounds like snapping or creaking usually when weight is present on the wheel however bad bearings can also act differently under a load...
 
Last edited:
Yes, there's a sympathetic vibration going on. Get aPark spoke wrench...the blue one if your spokes are 12 ga put a small drop of a licht oil on each nipple where it goes into the spoke and try 1/2 turn all around...it won't take much to move the vibration into unusable territory outside your usage range. Tire pressure might figure in, but only try one thing at a time.

@Rover1701 thanks for the noise info.. I have a little bit, and have thought it might be motor noise.

Only 100 mi. so far...will wait, then tighten spokes. Remember to check main crank screws too.
 
larry-new said:
Yes, there's a sympathetic vibration going on. Get aPark spoke wrench...the blue one if your spokes are 12 ga put a small drop of a licht oil on each nipple where it goes into the spoke and try 1/2 turn all around...it won't take much to move the vibration into unusable territory outside your usage range. Tire pressure might figure in, but only try one thing at a time.

@Rover1701 thanks for the noise info.. I have a little bit, and have thought it might be motor noise.

Only 100 mi. so far...will wait, then tighten spokes. Remember to check main crank screws too.
Click to expand...

Great feedback. My new Radrover already had the motor replaced. There was a knocking noise from rear hub that stopped when motor was off. That was easily diagnosed by Radpower and they quickly sent a new rear wheel/motor. First few weeks...all silent with new hub; then the current peculiar noise started. Not from rear hub, but sounds mid-bike. I’ll tweak spokes and test tire air pressure (separately) to see if it has an effect. I’m working on a Safeway to record a video for Radpower as this sound only occurs when riding. Keep you posted...Also, as I’m not an expert, I’m working with Velofix in my area....authorized Radpower Tech.
 
Peculiar Issue Solved!! Rover1701's suggestion that tire pressure may be the culprit was right on. Though tires felt same upon squeezing...the tire pressure on the rear versus the front was considerably different. Once I filled both tires to equal pressure.....that peculiar noticeably noise vibration disappeared. Thanks to all for sharing your expertise!!
 
and happy endings!
 
It never ceases to amaze me how the simplest of things like loose spokes or pedals can cause the strangest of noises and drive us nuts. I now have to add low air pressure to that list. Hopefully you can relax and fully enjoy your RadRover now. I love mine.
 
SteveC said:
Peculiar Issue Solved!! Rover1701's suggestion that tire pressure may be the culprit was right on. Though tires felt same upon squeezing...the tire pressure on the rear versus the front was considerably different. Once I filled both tires to equal pressure.....that peculiar noticeably noise vibration disappeared. Thanks to all for sharing your expertise!!
Click to expand...
Great!!!
Glad I could help in some small way.
Guess I should to take my own advice and check my tire pressure too...
 
I'm having the same issue on my RadRover, with this sound appearing between 14.5 - 15.5 mph. I'll try leveling tire pressure and check if it would solve an issue in my case.
 
I had a similar condition on my Sondors. Seemed like a harmonic frequency kind of thing to me. Just took the slightest change to make it stop. Tires, rotors, something would get in a vibration. I either slowed a bit, or sped up. Went away.
 
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