Active Line Plus clicking noise

[JDH3rd]

I have a Bosch Active Line Plus motor on a 2019 Trek Dual Sport +. At about 400 miles I started getting a clicking noise that starts after 6-9 miles of riding (recording attached). My wife has the same bike and hers does not make any noise.

It's a tick…tick…tick sound when pedaling. It can start immediately, but usually after 6-9 miles. It might be heat related as the noise starts sooner on a hot day. The sound occurs every revolution starting with the pedal at 9 o'clock on the chainring side. It happens when motor is on and off. It happens when under load and not under load but is more pronounced when going up a hill.

Bosch told me to take it to a certified bike shop, but they are backed up for weeks because of COVID 19 bike demand. I am convinced it is the motor, which is still under warranty, but am concerned it will be had to reproduce by a shop since it usually only happens after miles of riding.

I found a Bosch tech bulletin that describes the problem perfectly, but it was for a much earlier Bosch motor design. At this point I am going to wait until winter when I don't ride my bike and have it looked at then.

Any other thoughts as to what the problem could be? The drivetrain, pedals, etc. are in excellent shape.

 

[J.R.]

I have had that tick... tick... and it has always been a bearing. Happened on many of my bikes over the years. I ride mostly off road and the fine dust works it's way into bearings. Most often it's a pedal bearing, which is easy to take apart, clean and relube or replace the cartridge bearing. Next could be the bottom bracket. In your case that's inside the drive. There have been reports of bearings needing service inside the Bosch drive unit. That's not a fault with Bosch, it can happen on any bike's bottom bracket. I've also had to service the hub bearings, freewheel on my bikes, but from your description it doesn't sound like the problem is with the wheels.

I would do a process of elimination and start by servicing or replacing the pedals. Maybe you could put the pedals from your wife's bike on and see if that tick goes away. Some pedals use 2 cartridge bearings, some use 1 bearing and 1 bushing. Some really inexpensive pedals use bushings only. Try to find a diagram of your pedals and tear them down and do a complete clean and lube. Or buy a set you always wanted

 

[William - Bosch Team]

Hello!

A few things for a bicycle dealer to check would be:

- Crank arm bolt torque.

- Drive train adjustment, which is just as important on a brand-new unit as it is a well-used one. Cables will stretch, allowing minor misalignment. Derailleurs/ derailleur hangers can get slightly bent due to light contact while in storage or transport. A brand-new bike can also arrive with a slightly misaligned hanger, whether from factory error or transportation damage.

- Seatpost head bolt tightness. These can creak intermittently, as can the seat rails themselves. Same for stem bolts, but less common. (This is my second place theory, first is at the bottom of this post.)

- As J.R. mentioned, it can be the pedals... even if they are brand new.

The noise in the video does not sound like a bearing to me, but there are some other sounds in there too, so I'm not 100% sure.

I would suggest that you ask your shop to check all of your Drive Unit mounting bolts for proper torque (5 of them), and the mounting surfaces for cleanliness. This is a more common source of clicking/creaking. Sometimes, these bolts are not properly torqued from the OEM's assembler. Based on your description and your video, this is what it seems like to me.

 

[JDH3rd]

Thank you for your suggestions. I am going to swap the pedals as A.R. suggested. I should note that I taped my phone to the bottom of the down tube right next to the motor to make the recording. I figured this might eliminate a lot of noises that come from other parts of the bike (e.g. the seat post). I expect the dealer will check all the things you suggested anyway. Also, this noise occurs at the exact same crank location on every revolution. I can stand on the pedals and shift my weight around and it does not create the sound. I was mostly asking to see if anyone out there has had a similar problem. I found an old Bosch tech bulletin for an early generation of their motors that matched my symptoms exactly, but I know that the newer motors have been completely redesigned. In that case "The cause of the noise is that the chainring-side, right floating bearing makes jerky movements (due to soiling or lack of lubrication) when moving in the sliding seat, resulting in a sound."

 

[BlackHand]

I have had that tick... tick... and it has always been a bearing. Happened on many of my bikes over the years. I ride mostly off road and the fine dust works it's way into bearings. Most often it's a pedal bearing, which is easy to take apart, clean and relube or replace the cartridge bearing. Next could be the bottom bracket. In your case that's inside the drive. There have been reports of bearings needing service inside the Bosch drive unit. That's not a fault with Bosch, it can happen on any bike's bottom bracket. I've also had to service the hub bearings, freewheel on my bikes, but from your description it doesn't sound like the problem is with the wheels.

I would do a process of elimination and start by servicing or replacing the pedals. Maybe you could put the pedals from your wife's bike on and see if that tick goes away. Some pedals use 2 cartridge bearings, some use 1 bearing and 1 bushing. Some really inexpensive pedals use bushings only. Try to find a diagram of your pedals and tear them down and do a complete clean and lube. Or buy a set you always wanted

Thanks for this. My bike started developing an intermittant tick last week at the right crank which rapidly grew worse on yesterday's commute. I pulled off the old set of AtomLabs AirCorp pedals that I had on the bike for a cheap reject set of pedals that I had lying around. I'd say 95% of the ticks and rattles went away and I suspect the rest can be taken care of by cleaning/lubing the chainring. Saved me a trip to the LBS, I appreciate it.

JDH3rd, I hope your noises turned out to be as easily dealt with.

 

[JDH3rd]

Thanks for this. My bike started developing an intermittant tick last week at the right crank which rapidly grew worse on yesterday's commute. I pulled off the old set of AtomLabs AirCorp pedals that I had on the bike for a cheap reject set of pedals that I had lying around. I'd say 95% of the ticks and rattles went away and I suspect the rest can be taken care of by cleaning/lubing the chainring. Saved me a trip to the LBS, I appreciate it.

JDH3rd, I hope your noises turned out to be as easily dealt with.

Thanks for the support. My last two rides at > 20 miles made no noises at all. Go figure. The one before that started making a faint noise after 18 miles, which is better than before. It's as if this problem started slowly and is going away slowly. I am still convinced it came/is coming from the motor itself, but since I don't want to give up my only exercise during this "pandemic," I am just going to wait until winter when I don't ride my bike. The LBS near me want two weeks to even look at it. If the problem does not resurface before the warranty runs out in March, I guess I will just take my chances and assume it was just some anomaly.

I did swap the pedals (after the noise stopped) and the drivetrain is clean and lubed. My wife has the same bike, so I have something to compare it with.

 

[William - Bosch Team]

Sorry to hear you are still experiencing this issue. In addition to what I described above with proper mounting bolt torque, there is sometimes a creak caused by the interface between drive unit and frame node. When properly executed by the shop... removal of DU, cleaning of contact surfaces, and light greasing of bolts (followed by proper torque) has solved this creak. Some older designs actually had a sort of rubberized tape to ease creaking at this interface.

 

[JDH3rd]

I

Sorry to hear you are still experiencing this issue. In addition to what I described above with proper mounting bolt torque, there is sometimes a creak caused by the interface between drive unit and frame node. When properly executed by the shop... removal of DU, cleaning of contact surfaces, and light greasing of bolts (followed by proper torque) has solved this creak. Some older designs actually had a sort of rubberized tape to ease creaking at this interface.

Thanks. I will be taking it to a shop in winter because they are too busy now. (see my reply above). It seems to me it would be odd for a mounting noise to happen exactly at the same point in the crank rotation every time. Plus, it is definitely a clicking sound, like something catching, rather than a creaking sound. As I said in my reply above, the sound started slowly, became more frequent and louder, and now has all but disappeared the last 3 rides. Thanks again for your insights.

 

[JDH3rd]

Well, I posted in late July that the clicking sound was going away. It went away and has been quiet ever since. I have no idea why. In fact, the motor could not be any smoother or quieter for an ebike. My wife and I both have the 2019 Dual Sport + and I could not be more happy with them. It is more of a gravel bike that other ebikes with the wider tires. Too bad it was discontinued.