Rail (750Wh) Rail - Normal Bosch rattle?

[Oupy]

I see a lot of confusion and conjecture about the bosch rattle, what it sounds like, how loud it is, what conditions cause it etc.

I think I've found a way to recreate the rattle noise on demand, by agitating the chain ring quickly back and forward?

Bosch Rattle

Bosch rattle demonstration

youtube.com

I've tried this on a rail 9.8 and 7, both 2022 models and they both can create this sound, albeit with slightly different frequencies of carbon vs alloy.

You need to roll the bike around and move the cranks if you try this and feel no play at the chaining and subsequently no noise. Also lifting and dropping the rear end also can exhibit the noise.

• So is this the standard Bosch gen 4 rattle? Or is there possibly another issue at play?
• Can anyone else recreate this on their rails?

Hoping if this is a definitive way of recreating this sound it will save people time diagnosing bike noise if they know what the normal rattle sounds like. It sounds more like cables tapping/clicking to my ear and it travels up the frame towards the top tube.

 

[Stihldog]

That can sound like cables rattling.

 

[Mikerb]

The Bosch rattle...as you have identified is caused by pedal pob. That agitates the chainwheel which in turn causes meshed gears in the motor to chatter. How much or how little chatter you get depends on how well the shock deals with the terrain and the kinematic design of the rear triangle and shock linkage. My Whyte e180 rs with super plush 170mm rear travel but low anti dive/ pedal efficiency does not rattle. .My e160 RSX has a very different kinematic and does rattle on the roughest gravity runs but not noticeable otherwise. My wife's hardtail does not rattle at all!

 

[slomtbr]

It's the ratchet inside the motor - nothing to worry about.

bosch gen 4 rattle, reply from bosch

hi Put less than 200 miles on my team cube stereo and it seems to have the rattle everyone is talking about, which has got louder over time, to a point where I don't even want to ride it sounds broke. So I fired a few emails to Bosch this is what they said. The clacking and rattling noise is...

www.emtbforums.com

 

[Oupy]

So I've found an even more reliable method to generate the rattle - just grab the top of the cassette and pull back and forth.

Tested on 2 Rails:

Rail 9.8 Rattle

youtube.com

Rail 7 Rattle

youtube.com

I think it's safe to conclude all of them do this then?
I don't even mind the noise tbh i just want to know if this is normal or if it's excessive compared to other peoples rails?

 

[Jujujuice]

So I've found an even more reliable method to generate the rattle - just grab the top of the cassette and pull back and forth.

Tested on 2 Rails:

Rail 9.8 Rattle

youtube.com

Rail 7 Rattle

youtube.com

I think it's safe to conclude all of them do this then?
I don't even mind the noise tbh i just want to know if this is normal or if it's excessive compared to other peoples rails?

My rail 9.8xt does not really make that noise . This is a video of me riding just to help compare?

 

[Oupy]

Thanks Juju - I can definitely hear it in your vid over the rougher sections. The smoother sections not so much (which is the same as mine). Are you able to give the cassette a tug to see if it makes the noise?

 

[Jujujuice]

Thanks Juju - I can definitely hear it in your vid over the rougher sections. The smoother sections not so much (which is the same as mine). Are you able to give the cassette a tug to see if it makes the noise?

yup my rail and my wife's rail does make that noise with the cassette tugging. It is just the bosch motor rattle.

 

[Oupy]

Thanks for testing that for me, much appreciated! Definitely puts my mind at ease.
It seems this is indeed the normal bosch rattle and part of the Bosch gen 4 and shimano ep8 design for better or worse. I was in a bike store this afternoon and could replicate a similar sound on an EP8 equipped bike.

It's really not that bad, but hopefully if people know what it sounds like they won't freak out that their bike is falling apart when they hear it!

 

[JP-NZ]

I just tried it on mine and all I can hear is the cassette on the pawls. Same noise as a non ebike. Definitely nowhere near as loud as the video posted.

Mines only done 18km so may get worse hah

 

[Oupy]

Mine can be like that too but i found if i rotate the casette backwards a bit and then try the movement it will make the noise.

 

[mak]

I've never been bothered by the bosch rattle, to be honest I've never really noticed it, I've just moved over to a shimano equipped bike. Holy Sh%t now there's a rattle for you to get your teeth into

 

[Mikerb]

Tame the pedal kick and you get rid of most of the rattle.....if the kinematics of your rear triangle allow. Even descending in a mid cassette gear rather than on a small cog helps.

 

[irie]

Cut a flap from 1mm neoprene to protect the rear pivots and fix it with a cable tie just above the charging port (obviously). Been posted before but worth reposting ...