Trek Allant+ 7S: Slight Vibration Emitting from Bosch Performance Speed motor

Dallant

Well-Known Member
Region
USA
More data- downhill in top gear & touring mode going full tit around 45-50kpm. Vibrations through pedalS bigtime.
Then on the flat in Sport going full tilt pedalling at around 45kpm bad vibration, then head wind hit and slowEd me to 35. This increase of torque immediately stopped vibration. Spent rest of commute tested gears, modes & turning motor off while riding.
Summary, the increase of resistance seems to decrease or remove the vibration, but on a bike that is designed to go fast and you have good air & road conditions you will get major vibrations at speed.
So if you ride like an old nana then no problem, buy one. Unfortunately after 46 motorcycling I feel the need for speed 🙃
Completely opposite of my experience and I would never describe the very infrequent vibrations as anything other than minor. I don’t know who set your bike up but I’d take it back for an adjustment.
 

Alaskan

Well-Known Member
First, if you feel the need for speed why are you pedaling "like an old Nana" at 45 RPMs, way below the efficiency point? Both the Bosch system and you produce more torque with less wattage at higher RPMs. Even on a acoustic bike, one needs to maintain a minimum cadence of 60 while the optimal is closer to 80 RPMs. The Bosch system does its best work assisting you based on these same numbers.

That said, I am not at all convinced that there is not a problem with the bike's setup, perhaps a chainline issue with a slight offset at one of the dropouts or some kind of tweaking at the crank. It is not unusual to get a little vibration at some harmonic point in the cadence continuum but the kind of dramatic vibration you are describing is not right. Your Trek shop should be eager to help in identifying the source and providing a durable remedy.
 

JonP

New Member
Region
New Zealand
First, if you feel the need for speed why are you pedaling "like an old Nana" at 45 RPMs, way below the efficiency point? Both the Bosch system and you produce more torque with less wattage at higher RPMs. Even on a acoustic bike, one needs to maintain a minimum cadence of 60 while the optimal is closer to 80 RPMs. The Bosch system does its best work assisting you based on these same numbers.

That said, I am not at all convinced that there is not a problem with the bike's setup, perhaps a chainline issue with a slight offset at one of the dropouts or some kind of tweaking at the crank. It is not unusual to get a little vibration at some harmonic point in the cadence continuum but the kind of dramatic vibration you are describing is not right. Your Trek shop should be eager to help in identifying the source and providing a durable remedy.
Sorry “kilometres per hour” is the measurement I’m talking about, as in 45 kilometres per hour.
I see no indicator on my unit to tell me my Revs Per Minute.
My screen tells me the speed.
 

webcurl

Well-Known Member
Sorry “kilometres per hour” is the measurement I’m talking about, as in 45 kilometres per hour.
I see no indicator on my unit to tell me my Revs Per Minute.
My screen tells me the speed.
After Motorcycling for so long at speed & then getting on a Bosch ebike it's more like 45 bpm :)
 

JonP

New Member
Region
New Zealand
Completely opposite of my experience and I would never describe the very infrequent vibrations as anything other than minor. I don’t know who set your bike up but I’d take it back for an adjustment.
So it seems going by your & other comments this vibration that is intense and regular on some Trek Allant7 bikes and irregular and less noticeable on others is a failing on either setup or part.
Hopefully it is then something easily adjusted as opposed to poor quality control by the manufacturerS. ( see the capital S, that’s a bug in the forum software. Forum platforms seem infested with such things. )
 

Dallant

Well-Known Member
Region
USA
So it seems going by your & other comments this vibration that is intense and regular on some Trek Allant7 bikes and irregular and less noticeable on others is a failing on either setup or part.
Hopefully it is then something easily adjusted as opposed to poor quality control by the manufacturerS. ( see the capital S, that’s a bug in the forum software. Forum platforms seem infested with such things. )
As far as I’m concerned, it’s just the way it works. It’s never affected the operation of my Allant+7 in any negative way and I only ever noticed it because others here have complained about it. Every vehicle I’ve ever owned has had its idiosyncrasies and that’s all it is to me. Kinda like how the Bosch makes more noise than some other motors. If it bothered me, I’d take it in for testing.
 

JonP

New Member
Region
New Zealand
Well taken bike into store, the mechanics feel the vibrations and are going to ask Bosch about it. But I have just had the chance to test ride the same bike in another store and it is as horrible as mine with the pedal vibration at speed and reduced torque. When I mentioned this to the guy there they said “oh that’s the Bosch motor for you”. So I’m going for a refund as every other electric bike I’ve ridden is sans pedal vibration and a different motor manufacturer.
 

Alaskan

Well-Known Member
Barking up the wrong tree. Clearly a hasty and faulty conclusion. I have the Allant 9.9S with the 12 speed Shimano drive train and have never had that problem, nor have I seen it on any of the other 6 Bosch powered bikes that I have owned.


Just curious is the clutch on the XT derailleur engaged or disengaged? Has the chain line been carefully inspected for any misalignment? What chain lube is being used?
 
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JonP

New Member
Region
New Zealand
Barking up the wrong tree. Clearly a hasty and faulty conclusion. I have the Allant 9.9S with the 12 speed Shimano drive train and have never had that problem, not have I seen it on any of the other 6 Bosch powered bikes that I have owned.

Just curious is the clutch on the XT derailleur engaged or disengaged? Has the chain line been carefully inspected for any misalignment? What chain lube is being used?
Brand new bikes. It’s a vibration coming from the engines change of torque. Maybe it’s a Allant 7 motor issue. Don’t know, don’t care. Two of the same brand new bikes that have the exact same vibration under the same conditions and other riders have felt the same, so pretty safe to say it’s the motor functioning in a way to create an uncomfortable vibration. If your bikes don’t have that problem then that’s good for you. None of the other eBikes I own or have ridden do this. It is uncomfortable and unacceptable in an expensive bike.
 

Akrotiri

Well-Known Member
Region
Europe
Brand new bikes. It’s a vibration coming from the engines change of torque. Maybe it’s a Allant 7 motor issue. Don’t know, don’t care. Two of the same brand new bikes that have the exact same vibration under the same conditions and other riders have felt the same, so pretty safe to say it’s the motor functioning in a way to create an uncomfortable vibration. If your bikes don’t have that problem then that’s good for you. None of the other eBikes I own or have ridden do this. It is uncomfortable and unacceptable in an expensive bike.
Can you post some pictures of the drivetrain side of your allant at different angles?

This way we can visually inspect and confirm if anything like the derailleur needs a simple adjustment or if your chain is perhaps too short or not well maintained.
 

JonP

New Member
Region
New Zealand
Can you post some pictures of the drivetrain side of your allant at different angles?

This way we can visually inspect and confirm if anything like the derailleur needs a simple adjustment or if your chain is perhaps too short or not well maintained.

BRAND NEW BIKES. Are you imagining new bikes set up from different technicians in different countries bizarrely have the same issue with their chains and gears. If you read carefully the description of what triggers the vibration what stands out is the motor and how it delivers the power. What is actually vibrating is an answer that Bosch & Trek knows but if they will pass the knowledge on is a bigger mystery. Probably not as then they’ll have to offer a worldwide fix and not enough people can be arsed to complain about it.
Go into a store and take one for a hard test ride, if you enjoy a foot massage then it’s a good buy.
 

JonP

New Member
Region
New Zealand
I stand corrected further research shows Bosch has acknowledged this noise/vibration issue to their new motor -
This explains why the Trek Allant 7 could be unfortunately particularly sensitive to picking up and amplifying this motor noise. So really a design flaw from Trek to not make allowances for this Bosch feature.
Excerpt from :

The 4 Best 2020 eMTB Motor Systems Reviewed - Bosch vs Brose vs Shimano vs Fazua Ridden & Rated​


Talking about noise, the absolutely biggest downside of Bosch’s latest design is a metallic clacking noise when the engine is unloaded and rolling over uneven ground, not unlike that of bad chain slap, coming from the motor itself – something I’ve never experienced with any competitor’s product. On some bikes equipped with the new Performance CX it’s more noticeable than on others. We checked in with Bosch and got the following explanation:

When encountering technical terrain on an eBike or eMTB, a vibration of the chain/chainring can occur. Those vibrations can be transferred to the frame, the drive unit and to the inner gear wheel (inside the drive unit). How much vibration is transferred depends on the type of bike (for example hardtail vs full suspension and aluminum vs carbon). In some cases, when freewheeling a metallic sound can be generated when the inner gear wheel is not under the stress of pedaling.

We have been able to recreate this occurrence with different drive units – both from Bosch and competitors of Bosch. The new Performance Line CX is possibly a little more sensitive and the noise is slightly louder than the noise of the other drive units. The CX has a high power density, a highly efficient gearing mechanism and incredibly smooth-running gears. Paired with reduced weight, lower wall thickness and improved heat release it is easier for mechanical noises to be omitted. But performance, efficiency, heat removal and heat-resistance are more important to us.

Usually this noise is drowned out by the sounds of the bike on the trail when descending. Knowing the occurrence, it is easy to reproduce the noise, but the noise does not have any influence on the performance, functionality or reliability of the motor.


Event though this noise is not at a level that would cause me to not ride a Bosch equipped bike anymore, you simply cannot unhear it. With every development from derailleur to chain protector over the past few years to keep a bike as quiet as possible, hearing the clacking noise when rolling over uneven terrain without the motor being engaged is simply annoying.
 

Akrotiri

Well-Known Member
Region
Europe
I stand corrected further research shows Bosch has acknowledged this noise/vibration issue to their new motor -
This explains why the Trek Allant 7 could be unfortunately particularly sensitive to picking up and amplifying this motor noise. So really a design flaw from Trek to not make allowances for this Bosch feature.
Excerpt from :

The 4 Best 2020 eMTB Motor Systems Reviewed - Bosch vs Brose vs Shimano vs Fazua Ridden & Rated​


Talking about noise, the absolutely biggest downside of Bosch’s latest design is a metallic clacking noise when the engine is unloaded and rolling over uneven ground, not unlike that of bad chain slap, coming from the motor itself – something I’ve never experienced with any competitor’s product. On some bikes equipped with the new Performance CX it’s more noticeable than on others. We checked in with Bosch and got the following explanation:

When encountering technical terrain on an eBike or eMTB, a vibration of the chain/chainring can occur. Those vibrations can be transferred to the frame, the drive unit and to the inner gear wheel (inside the drive unit). How much vibration is transferred depends on the type of bike (for example hardtail vs full suspension and aluminum vs carbon). In some cases, when freewheeling a metallic sound can be generated when the inner gear wheel is not under the stress of pedaling.

We have been able to recreate this occurrence with different drive units – both from Bosch and competitors of Bosch. The new Performance Line CX is possibly a little more sensitive and the noise is slightly louder than the noise of the other drive units. The CX has a high power density, a highly efficient gearing mechanism and incredibly smooth-running gears. Paired with reduced weight, lower wall thickness and improved heat release it is easier for mechanical noises to be omitted. But performance, efficiency, heat removal and heat-resistance are more important to us.

Usually this noise is drowned out by the sounds of the bike on the trail when descending. Knowing the occurrence, it is easy to reproduce the noise, but the noise does not have any influence on the performance, functionality or reliability of the motor.


Event though this noise is not at a level that would cause me to not ride a Bosch equipped bike anymore, you simply cannot unhear it. With every development from derailleur to chain protector over the past few years to keep a bike as quiet as possible, hearing the clacking noise when rolling over uneven terrain without the motor being engaged is simply annoying.
No offence but I’m starting to think you have an agenda and also I don’t believe you own a trek allant.

Unless you can prove me wrong with pics of your allant with a Bosch Gen 4 motor.
 

Dallant

Well-Known Member
Region
USA
Well taken bike into store, the mechanics feel the vibrations and are going to ask Bosch about it. But I have just had the chance to test ride the same bike in another store and it is as horrible as mine with the pedal vibration at speed and reduced torque. When I mentioned this to the guy there they said “oh that’s the Bosch motor for you”. So I’m going for a refund as every other electric bike I’ve ridden is sans pedal vibration and a different motor manufacturer.
😂Reduced torque? Never.
 

JonP

New Member
Region
New Zealand
No offence but I’m starting to think you have an agenda and also I don’t believe you own a trek allant.

Unless you can prove me wrong with pics of your allant with a Bosch Gen 4 motor.
No offence but read the review article that explains what causes issues with the new Bosch motor.
BAD11851-9070-493F-9238-D96B983523F0.jpeg
 

Akrotiri

Well-Known Member
Region
Europe
No offence but read the review article that explains what causes issues with the new Bosch motor.
View attachment 87621
There’s nothing wrong with the motors. If there was there would have been recalls.

If you’re not happy with your purchase return it and get your full refund then purchase a specialized with the bullet proof Brose motors. I heard those are very reliable.

You made your point but you’re starting to come off as having an agenda and trying to take down or hurt Bosch’s ebike division sales.

I’m sure you realize how large of a company Bosch is and how long they have been around. A couple of negative threads on EBR that may or may not be searchable on Google cache searches won’t hurt them. Their not a fast casual neighborhood restaurant so they are impervious to that sort of thing.

You’re unhappy with your purchase and you think your motor is defective. Got it, understood. You’re returning it for a full refund and then purchasing a reliable ebike that is not a Bosch.

Good.

You should get your money back if the product you purchased isn’t working as intended.

If you have any cars sell those too because it uses Bosch technology also and you shouldn’t support Bosch and their defective products.

End of story and thread. Have a good one and ride on when you get your new reliable e-bike.
 
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JonP

New Member
Region
New Zealand
There’s nothing wrong with the motors. If there was there would have been recalls.

If you’re not happy with your purchase return it and get your full refund then purchase a specialized with the bullet proof Brose motors. I heard those are very reliable.

You made your point but you’re starting to come off as having an agenda and trying to take down or hurt Bosch’s ebike division sales.

I’m sure you realize how large of a company Bosch is and how long they have been around. A couple of negative threads on EBR that may or may not be searchable on Google cache searches won’t hurt them. Their not a fast casual neighborhood restaurant so they are impervious to that sort of thing.

You’re unhappy with your purchase and you think your motor is defective. Got it, understood. You’re returning it for a full refund and then purchasing a reliable ebike that is not a Bosch.

Good.

You should get your money back if the product you purchased isn’t working as intended.

If you have any cars sell those too because it uses Bosch technology also and you shouldn’t support Bosch and their defective products.

End of story and thread. Have a good one and ride on when you get your new reliable e-bike.
You seem to have difficulty with English comprehension and apology accepted for accusing me of lying about ownership, would you like a copy of the receipt or was the picture sufficient?
If you read the posts and understood them you would see I clearly stated, after getting the technical data available to anyone else here, that I posted-
“I stand corrected further research shows Bosch has acknowledged this noise/vibration issue to their new motor -
This explains why the Trek Allant 7 could be unfortunately particularly sensitive to picking up and amplifying this motor noise. So really a design flaw from Trek to not make allowances for this Bosch feature.”

I now know the motors are sound, very good in fact, as I bothered to investigate instead of pontificate. I just don’t like the clacking motor noise and I feel Trek should have done a better job in toning this down.

I have provided an answer to the threads initial question that is backed up by research, personal experience and manufacturers own data. As far as I’m concerned that ends it for me. I certainly hope anyone buying a bike with this motor does a test ride to see if it falls within their comfort zone & when they get one without a test ride and wonder WTF is going on they’ll appreciate what they learn here.
 

Akrotiri

Well-Known Member
Region
Europe
You seem to have difficulty with English comprehension and apology accepted for accusing me of lying about ownership, would you like a copy of the receipt or was the picture sufficient?
If you read the posts and understood them you would see I clearly stated, after getting the technical data available to anyone else here, that I posted-
“I stand corrected further research shows Bosch has acknowledged this noise/vibration issue to their new motor -
This explains why the Trek Allant 7 could be unfortunately particularly sensitive to picking up and amplifying this motor noise. So really a design flaw from Trek to not make allowances for this Bosch feature.”

I now know the motors are sound, very good in fact, as I bothered to investigate instead of pontificate. I just don’t like the clacking motor noise and I feel Trek should have done a better job in toning this down.

I have provided an answer to the threads initial question that is backed up by research, personal experience and manufacturers own data. As far as I’m concerned that ends it for me. I certainly hope anyone buying a bike with this motor does a test ride to see if it falls within their comfort zone & when they get one without a test ride and wonder WTF is going on they’ll appreciate what they learn here.
You posted pics of your allant so I believe that you have one now.

Noises coming from the aluminium frame because of the motor isn’t a design flaw, it’s physics. Noise notoriously travels on bicycles and e-bikes. It’s always been that way and e-bikes amplify those noises with the added power/torque.

So Bosch acknowledged the noise just like Shimano acknowledged their new EP8 motor knocking on technical trails, so what. There’s nothing to fix. That’s why Bosch didn’t mention any fix or recall.

Don’t like it?

Return the bike because you don’t like the noise and the vibration at your sensitive feet and purchase a e-bike that is as silent as a mouse in a barn. Good luck with that.

I never apologized to you so there is no apology for you to accept.
 

Alaskan

Well-Known Member
@JonP There have been several people like myself who have been trying to help you with possible remote diagnosis. We have asked specific questions which you have chosen not to answer. The way you are handling this tells me you are just here to gripe and go off on all the evil companies that are cheating you, rather than working with people here that have a year or more experience with the bike you are here to whine about. Good luck with that.

It is not unusual to have to work out a few bugs on any new bike, some caused by the component maker, some by the OEM, some by the Lbs that set it ip

A bit of patience is often rewarded with a great bike with the no ongoing issues.
 
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Dallant

Well-Known Member
Region
USA
I’ve never heard clacking. You are the very first I’ve ever heard with clacking and torque loss.
A little vibration and the normal motor noise but never any clack or loss of torque. You musta got a bad one which happens with any manufactured product. Best of luck.