Gen 4 rattle

[Bazzb1973]

I know the Gen 4 are known for rattle when coasting or pedals arnt under load but mines got similar rattle/knock even when I'm pedalling ,I've checked everything possible linkages cables etc,anyone else had same issue ,800miles on a cube

 

[Jamze]

You can usually isolate a noise by moving around on the bike. Stand up/sit down/feet off the pedals that sort of stuff.

I'd be thinking headset or motor bolts.

 

[Bazzb1973]

You can usually isolate a noise by moving around on the bike. Stand up/sit down/feet off the pedals that sort of stuff.

I'd be thinking headset or motor bolts.

All been checked,it's definitely from motor just wondered if happen to anyone else

 

[Jamze]

My gen 4 is as expected - knocks when you freewheel over rough ground. I'd get the motor checked if you are sure it's the motor. Battery rattle?

 

[Bazzb1973]

My gen 4 is as expected - knocks when you freewheel over rough ground. I'd get the motor checked if you are sure it's the motor. Battery rattle?

Na it's not battery ,the noise is similar to the usual gen 4 knock more like a clunk

 

[GrahamPaul]

The first time I heard that rattle when I was pedalling, I was sure it was the motor... it was cable slap inside the battery compartment. The second time I heard that rattle and was convinced it was from the motor... it was the back axle in need of a bit of grease. The third time I heard that rattle, WHICH DEFINITELY CAME FROM THE MOTOR... the seat post needed regreasing. ?

As the mechanic said: the Gen 4 is pretty reliable.

 

[GrahamPaul]

Na it's not battery ,the noise is similar to the usual gen 4 knock more like a clunk

Here, have a listen to this and see if your noises are the same...

My Motor WORKS ! - Survey

No one in their right mind would choose a hub motor for actual mountainbiking I had to think about that but yes very true. The 11 year old Crystalyte 5304 I have powers the hefty beast uphill at about the same speed as gravity pulls it downhill. With a 9-speed gearbox, I pedal no matter what...

www.emtbforums.com

 

[Bazzb1973]

The first time I heard that rattle when I was pedalling, I was sure it was the motor... it was cable slap inside the battery compartment. The second time I heard that rattle and was convinced it was from the motor... it was the back axle in need of a bit of grease. The third time I heard that rattle, WHICH DEFINITELY CAME FROM THE MOTOR... the seat post needed regreasing. ?

As the mechanic said: the Gen 4 is pretty reliable.

How would grease on axle stop rattle same as seat post who told you this lbs

 

[Stihldog]

I have almost 4K on my gen4 and still get the rattle. The battery might be the source of the noise (Trek Rail 9.7). Ive seen pieces of foam with one sticky side be placed in the battery compartment. It doesn’t sound like cable slap.
But if its the motor...how do ya fix that?

 

[Paul Mac]

Also check chainring isn't coming loose

 

[GrahamPaul]

How would grease on axle stop rattle same as seat post who told you this lbs

So... you press down on the left pedal and there's this horrible noise. A kind of grinding noise, followed by clunking noise... definitely a bearing gone in the motor...

Took the bike straight into the LBS. Demonstrated the noise to the mechanic. Who unscrewed the rear axle, greased it and sent me on my way... on a quiet, clunkless, grindless bike...

The time with the seat post, again it was pressing down on the left pedal gave me this horrible grinding noise and a clunk. Every time someone puts up a post on here, one of the things to check before tearing into the LBS is the grease on the seat tube... So, I'd torqued motor bolts, checked the spider retaining nut. Torqued the cranks. Still the noise was there. Checked to make sure the rear axle didn't need grease (in truth, the first thing I did).

Last thing before packing up the bike and driving to the shop was the seat post. It's a bastard because the outer for the dropper post cable is really hard to move to get the post out of the seat tube. Battled with it for a good while. Greased it well and... silence.

 

[GrahamPaul]

But if its the motor...how do ya fix that?

New motor. They're all still under warranty.

 

[Stihldog]

Took the bike straight into the LBS. Demonstrated the noise to the mechanic. Who unscrewed the rear axle, greased it and sent me on my way...

Last thing before packing up the bike and driving to the shop was the seat post. It's a bastard because the outer for the dropper post cable is really hard to move to get the post out of the seat tube. Battled with it for a good while. Greased it well and... silence.

There are 9 gen4 motors within shouting distance of my home. (All Trek). The only complaint seems to be the rattling noise on some.
I’m gonna watch, or listen, to some of those issues since I seem to be the adopted mechanic in my neighborhood. Little solutions like you described might save a lot of grief. ( 2months for a service appointment at the LBS).

 

[Bazzb1973]

I've put foam under battery it's not that, everythings tight I've had motor out every things torqued up,spindles and seat post noise tend to be more creaky ,the noise I've got is more metallic knock and it occurs even when your pedalling steady over small square edge bumps not with excessive pressure to cause creacks etc,it's going to shop I've spent past 4 weeks tracing it

 

[Bazzb1973]

Just an update had it back to shop today noise is from motor its getting exchanged under warranty