Is my E8000 about to explode?

GrumpyMTBMan

Member
May 19, 2022
6
3
UK
Hi, looking for some opinions on this. Last couple of rides I started noticing a weird noise. The bike is a YT Decoy Shred 2020 which I've had from new since end of July 2021 (2 years, 3 months). Easiest way to explain the noise is through this video I recorded last night.

The noise only seems to occur under heavy load, like climbing a steep hill. It's noticeable in ECO, Trail and Boost, but louder in Boost. It also occurs if I switch the motor off. There doesn't seem to be any issue with the bottom bracket bearings; no play in the crank arms etc. If I rotate the BB driveshaft by hand its quiet going backwards and, well sounds like a motor going forwards. There also doesn't seem to be any drop in assistance level or slipping etc. Apart from the noise, it rides and goes as normal. Chain is new (probably only 50km) and cassette is fairly new.
 

GrumpyMTBMan

Member
May 19, 2022
6
3
UK
I did have aftermarket alumnium jockey wheels on, but replaced them for the stock Shimano plastic ones and it still makes the same noise.
 

franciscoasismm

Active member
May 31, 2021
193
216
Badajoz
Hi, looking for some opinions on this. Last couple of rides I started noticing a weird noise. The bike is a YT Decoy Shred 2020 which I've had from new since end of July 2021 (2 years, 3 months). Easiest way to explain the noise is through this video I recorded last night.

The noise only seems to occur under heavy load, like climbing a steep hill. It's noticeable in ECO, Trail and Boost, but louder in Boost. It also occurs if I switch the motor off. There doesn't seem to be any issue with the bottom bracket bearings; no play in the crank arms etc. If I rotate the BB driveshaft by hand its quiet going backwards and, well sounds like a motor going forwards. There also doesn't seem to be any drop in assistance level or slipping etc. Apart from the noise, it rides and goes as normal. Chain is new (probably only 50km) and cassette is fairly new.
 

S13

Active member
Mar 1, 2021
231
136
NL
Did you put the new narrow / wide chain correctly on the chainring?
 

jcismo1

Member
Jul 22, 2021
44
40
Colorado
Yup, that noise sounds familiar. I’d hit some rough stuff and it started making the noise. I thought for sure that the motor was toast. I discovered that the chain somehow ended up out of sync with the narrow/wide jockeys wheel on the derailleur. The chain was just a little worn I guess, because I put on a new chain and haven’t had the problem since.
 

franciscoasismm

Active member
May 31, 2021
193
216
Badajoz
Hola, busco opiniones sobre esto. En los últimos viajes comencé a notar un ruido extraño. La bicicleta es una YT Decoy Shred 2020 que tengo nueva desde finales de julio de 2021 (2 años, 3 meses). La forma más sencilla de explicar el ruido es a través de este vídeo que grabé anoche .

El ruido sólo parece ocurrir bajo una carga pesada, como subir una colina empinada. Se nota en ECO, Trail y Boost, pero más fuerte en Boost. También ocurre si apago el motor. No parece haber ningún problema con los rodamientos del pedalier; no hay juego en los brazos de la biela, etc. Si giro el eje de transmisión BB con la mano, es silencioso al retroceder y suena como un motor que avanza. Tampoco parece haber ninguna caída en el nivel de asistencia ni resbalones, etc. Aparte del ruido, se conduce y funciona con normalidad. La cadena es nueva (probablemente sólo 50 km) y el casete es bastante nuevo.

Send the video to him and he'll tell you what's wrong with him
 
Last edited:

GrumpyMTBMan

Member
May 19, 2022
6
3
UK
Yup, that noise sounds familiar. I’d hit some rough stuff and it started making the noise. I thought for sure that the motor was toast. I discovered that the chain somehow ended up out of sync with the narrow/wide jockeys wheel on the derailleur. The chain was just a little worn I guess, because I put on a new chain and haven’t had the problem since.
It's weird because I've recently put on a new chain. I took it to my local bike shop today to get a 2nd opinion, and before I did I put the old chain, old cassette etc back on and when I got to the shop it wouldn't make the noise... now I'm thinking the out-of-sync thing could be it. The only part of the drivetrain that's out of step in terms of age/wear is the chainring. So my next step will be new chainring, chain, cassette and jockey wheels and will see if that solves it. Thanks.
 

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