Bosch CX Gen 5 rattle

I too have suffered with the rotational click / knocking on a brand new vala.
My shop diagnosed and organized a warranty motor replacement which was fitted and indeed solved the knocking for the next few rides, and then it returned.
As suggested above I loosened and removed the motor retaining nuts, degreased and refitted.
I also noticed the one up seat post collar( not the frame collar) was a bit loose and tightened this by hand.
Just completed a 35mile /3000feet ride with no more knocking!
Hoping this is a permanent fix, but clearly good areas to focus on.
 
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Mangustonius said:
I have a trek gen5 and managed to pinpoint the rattle to the battery lock/release mechanism. It's very loose and rattles like hell. If the Vala has a smiliar one then this might be your culprit. It can be replaced witha n ABUS key, not sure if this will help so I'm just rolling with the rattle for now. It's not a big problem once you know what's rattling - at least in my case :D.
Click to expand...
I have a trek gen 5 too and started to notice this rattle and tracked it down to the lock mechanism too.

I removed it this evening, it's straightforward to do.

Take battery out.
There are 4 screws with torx heads to be removed. Two are beside the mechanism under the downtime and two are down near the bottom bracket.

This will allow you to remove the mechanism and then will further screw to release it.

I removed the pin that the was the cause of the rattle on mine that holds the spring, put some thin tape around it and reassembled everything and rattle is gone.

Hope that helps.
 
trekRailIRL said:
I have a trek gen 5 too and started to notice this rattle and tracked it down to the lock mechanism too.

I removed it this evening, it's straightforward to do.

Take battery out.
There are 4 screws with torx heads to be removed. Two are beside the mechanism under the downtime and two are down near the bottom bracket.

This will allow you to remove the mechanism and then will further screw to release it.

I removed the pin that the was the cause of the rattle on mine that holds the spring, put some thin tape around it and reassembled everything and rattle is gone.

Hope that helps.
Click to expand...
Great to hear that it worked for you! What frame size are you on? I'm on a XL and it looks like I have to drop the motor to remove the battery bracket. Don't want to do it atm, so I'm just rolling with the annoying rattle. Will give it a go during winter maintenace for sure.
 
Mangustonius said:
Great to hear that it worked for you! What frame size are you on? I'm on a XL and it looks like I have to drop the motor to remove the battery bracket. Don't want to do it atm, so I'm just rolling with the annoying rattle. Will give it a go during winter maintenace for sure.
Click to expand...
I have a large frame.

I'd be surprised if you have to do that just because of the larger frame size.

Did you give it a go?
 
trekRailIRL said:
I have a large frame.

I'd be surprised if you have to do that just because of the larger frame size.

Did you give it a go?
Click to expand...

I did and was really suprised - thought this might be an issue with small frames, not on the largest size.
I unscrewed all 4 bolts and wiggled the whole bracket within the downtube - to no avail. My only option seems to be dropping the motor :/
 
I have the bullet 4, and my rattle sound sounds like a loose hub or a loose brake caliper, I was able to pinpoint the rattle to a tiny amount of play on the lower shock mounting bolt.
Santa Cruz specifies 15 Newton meters of torque for the bolt, but even that allows for a small amount of play between the bolt and the shock bolt sleeve
 
Ea9818 said:
I have the bullet 4, and my rattle sound sounds like a loose hub or a loose brake caliper, I was able to pinpoint the rattle to a tiny amount of play on the lower shock mounting bolt.
Santa Cruz specifies 15 Newton meters of torque for the bolt, but even that allows for a small amount of play between the bolt and the shock bolt sleeve
Click to expand...
What was your fix? 16nm?
 
The issue is not the lock itself or the actuation method. It is the internal locking/release mechanism, which is identical regardless of whether it is operated by a key or by a hex bolt. Therefore, replacing the lock or actuation unit does not solve the problem. The noise is typically caused by play in the locking arm, an insufficient or weak spring, and tolerances between the locking arm (catch) and the battery’s locking interface. In addition, vertical micro-movement can occur in the mechanism under impacts from rough terrain. If the bike is not ridden downhill or on rough terrain such as roots and rocks, the issue may never occur. During riding, the mechanism vibrates and impacts the housing, which results in a constant rattling or knocking noise. The “clonk clonk” sound comes from the internal locking mechanism striking its housing.
 
twisted_trails said:
I know, sorry, it just felt very much like classic motor rattle from shimano or previous gens bosches. Ultimately we'll probably get to "(insert bike part) rattle" title.

completely stock S build
Click to expand...
Did you ever track down the source of your rattle?

Sounds like everyone else here chased it down to non-motor issues on their bikes:

Loose dropper post collar:
Bosch CX Gen 5 rattle

Play in battery lock mechanism:
Bosch CX Gen 5 rattle

Loose shock bolt:
Bosch CX Gen 5 rattle
 
Removed the locks and other gubbins from wife and my 2022 Trek Rail 5's. Made sure the batteries are well bolted in and cables above them are secure. Only get a bit of 'noise' from my bike (>5,000 mile Bosch non-smart) when descending on lumpy shit but hey, that's to be expected.

Got coil shocks (Ohlins) and forks (Smashpot) so no more messing with air springs (y).
 
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irie said:
Removed the locks and other gubbins from wife and my 2022 Trek Rail 5's. Made sure the batteries are well bolted in and cables above them are secure. Only get a bit of 'noise' from my bike (>5,000 mile Bosch non-smart) when descending on lumpy shit but hey, that's to be expected.

Got coil shocks (Ohlins) and forks (Smashpot) so no more messing with air springs (y).
Click to expand...
FYI 2022 Trek Rail would be the Gen 4 Bosch. That motor has a downhill knock/rattle by design (I.e. it's not indicative of a problem).

This thread is for the Gen 5 (current) Bosch, which was specifically redesigned to eliminate the knock/rattle.
 
Blownoutrides said:
FYI 2022 Trek Rail would be the Gen 4 Bosch. That motor has a downhill knock/rattle by design (I.e. it's not indicative of a problem).

This thread is for the Gen 5 (current) Bosch, which was specifically redesigned to eliminate the knock/rattle.
Click to expand...
My post was about battery locks and loose cables which as far as I am aware can cause rattles on all generations of Trek Rails. hth
 
trekRailIRL said:
I have a trek gen 5 too and started to notice this rattle and tracked it down to the lock mechanism too.

I removed it this evening, it's straightforward to do.

Take battery out.
There are 4 screws with torx heads to be removed. Two are beside the mechanism under the downtime and two are down near the bottom bracket.

This will allow you to remove the mechanism and then will further screw to release it.

I removed the pin that the was the cause of the rattle on mine that holds the spring, put some thin tape around it and reassembled everything and rattle is gone.

Hope that helps.
Click to expand...
Any more info on the specific part you taped? Pulled it all apart, there is the little latch cam with the spring, and then the pin that rotates it. Tape on that pin helped, or the main latch?
Thanks!
 
Blownoutrides said:
Did you ever track down the source of your rattle?

Sounds like everyone else here chased it down to non-motor issues on their bikes:

Loose dropper post collar:
Bosch CX Gen 5 rattle

Play in battery lock mechanism:
Bosch CX Gen 5 rattle

Loose shock bolt:
Bosch CX Gen 5 rattle
Click to expand...
I think mine is definitely coming from the one up dropper. Looks like I need to service and regrease it ever few rides otherwise rattle comes back, quite frustrating. Considering replacing it
 
Plummet said:
2900km on gen 5. Zero motor rattle.
Click to expand...
After the Gen 4 rattle on the Pole my #1 requirement for the next bike's motor was zero rattle.

Looked high and low for a used Gen 5 Crestline, then came very close to ordering a 181.2 but wasn't ready to bank on the promises of the unreleased M2 motor being rattle free (and also I have a problem with waiting).
 
effseetee said:
Any more info on the specific part you taped? Pulled it all apart, there is the little latch cam with the spring, and then the pin that rotates it. Tape on that pin helped, or the main latch?
Thanks!
Click to expand...
I can barely remember. I think it should be obvious when you shake the part when it's out where the rattle is coming from. I think I put the tape around the pin so it fitted more snuggly into the cam if that makes sense. Haven't had an issue since.

Also just reread what I wrote on the original post and the predictive text made it hardly make sense in places!
 
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trekRailIRL said:
I can barely remember. I think it should be obvious when you shake the part when it's out where the rattle is coming from. I think I put the tape around the pin so it fitted more snuggly into the camera if that makes sense. Haven't had an issue since.

Also just reread what I wrote on the original post and the predictive text made it hardly make sense in places!
Click to expand...
Gotcha - cheers. Size M you have to drop the whole motor to get that part out (did it yesterday) so just trying to make sure this is the last time i do it haha!

Thanks
 
Blownoutrides said:
After the Gen 4 rattle on the Pole my #1 requirement for the next bike's motor was zero rattle.

Looked high and low for a used Gen 5 Crestline, then came very close to ordering a 181.2 but wasn't ready to bank on the promises of the unreleased M2 motor being rattle free (and also I have a problem with waiting).
Click to expand...
Yeah, The Gen 5s180 is a unicorn for sure. Its a shame they didn't do more.

All the hype with DJI.... I'm sure i would enjoy a djI crestline. But the bosch gen 5 crestline is suits me down to the ground and i still think i have the best handling configuration and the best configurability with the options to run 400-600-800wh and range extender.

The 400wh config is sooo much fun. .... It doesnt really feel like a e bike with that heavy front end. Its more like a heavy stable mtb. I really enjoy that playfullness. Add the 600wh in and its still fun but feels more like an e-bike. I dont even want to put an 800wh in there.

Anyway i am acutely aware that if something happens to the bike then i wont be able to replace it with another one....
I hope by the time I need to replace the Crestline theres over bikes out there than offer the same handling feel.

No disrespect to all those 800wh dji bikes being released. But that heavy front end weight just makes em feel more dead at the front end and less playful and for me not as enjoyable.
 
Reviving this thread, I have the rattle in my lock, the bit the hex key goes into.
Gen 5 rail.
Is it possible to disassemble far enough to grease that barrel with like a thick teflon grease or put something like the old oneup dropper hack with some tape around it?
The rest of the bike is quiet just that damn lock is annoying
 
twisted_trails said:
lacing the lock or actuation unit does not solve the problem. The noise is typically caused by play in the locking arm, an insufficient or weak spring, and tolerances between the locking arm (catch) and the battery’s locking interface. In addition, vertical micro-movement can occur in the mechanism under impacts from rough terrain. If the bike is not ridden downhill or on rough terrain such as roots and rocks, the issue may never occur. During riding, the mechanism vibrates and impacts the housing, whi
Click to expand...
so how did it go? rattle from the motor gone?
 
any other gen5 bosch user with over 1000 miles, no rattle?
post your Bosch app / Strava screenhots / gopro/dji/whatever clips to confirm please.
 
alexwald said:
any other gen5 bosch user with over 1000 miles, no rattle?
post your Bosch app / Strava screenhots / gopro/dji/whatever clips to confirm please.
Click to expand...
Post screenshot to confirm?!

I've just over 1000miles on my trek rail with gen 5 motor. Bike had rattle when I got it new last summer. Quickly isolated the issue to the lock mechanism, took it out and fixed with some tape. Rattle free since. Those 1000miles have been rough with a heavy rider, not just cruising on tarmac.
 
I have 3k miles on my gen 5 cx equipped bullit, no rattles. I do have what might be a slipping sprag clutch... but zero rattles.
 
trekRailIRL said:
Yep you can take it out easily enough and wrap some tape around the barrel to sort it.
Click to expand...
Did you have to drop the motor for this? I can tell my cam latch is rattling on the pin so I would like to remove it and give it a shot. Rail+ 9.7 gen 5 size large.
 
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