Trying out new E-MTB

[Brian J]

Hi, I tried riding new E-MTB with full boost mode without power pedal assist, i did it in order to test its battery and ranger per charge, i was able to do it, but i found it was a bit abnormal when i heard the noise , 1st i thought the noise was from the chain , it happened when the speed was about 20km/h, the 2nd time i heard the noise was when i was starting to pick up speed after turning a corner, my customer said i had probably damaged the chainring or the cassette cog >? and maybe the noise is from the damage, i am still not sure if the noise was from engine, its a new bike, engine is new, i think i need to rule out the noise coming from engine, what do you guys think? if the noise was from chainring or cassette, what should i do next to make sure the bikes has no problem on its transmission system, I will send this bike to my customer as samples, so it must be in good quality, what should i do next to fix the possible damage to chainring or cassette?

 

[Zimmerframe]

i am still not sure if the noise was from engine, its a new bike, engine is new, i think i need to rule out the noise coming from engine, what do you guys think?

I agree. Maybe you need to put the bike on a stand and try running it through the gears with the motor. If possible, whilst applying some drag to the back wheel (maybe so it's just touching the floor, rather than holding the wheel).

 

[Haedesz]

Can you show us a closeup picture of the cassette and derailleur?

Are you using the right chain for the right cassette? ie 10 speed chain for 10speed cassette

Are you using the right chainring for the right cassette?

On your test ride, did you change gears while full on throttle instead of letting of the throttle?

What sound did you hear? grinding, tapping, repetitive, knocking,...

Do you have more than 1 bike (since you're selling these I guess) to replicate the problem?

 

[Brian J]

I was using 11 cog cassette, chain remained on the smallest cog, so that i would want to drain the battery in shortest time possible to find out the range kilometer for one charge, only after i tested using full boost mode without pedal assist, i knew it was not proper to use the smallest sprocket on the rear cassette while using full boost mode for like 70% of the time, so how to diagnose the noise issue, ?

 

[Brian J]

Can you show us a closeup picture of the cassette and derailleur?

Are you using the right chain for the right cassette? ie 10 speed chain for 10speed cassette

Are you using the right chainring for the right cassette?

On your test ride, did you change gears while full on throttle instead of letting of the throttle?

What sound did you hear? grinding, tapping, repetitive, knocking,...

Do you have more than 1 bike (since you're selling these I guess) to replicate the problem?

I don't have photos here, i will send later ok

Chain always stayed on the smallest sprocket of the 11 speed cassette, only 1 chain ring,

On my test ride, i didn't change gears while full on throttle,

The sound is like a 2 teeth on two cogs grinding each other,

Yes, 2 bikes have the same problem because the 2 bikes were used for the same test of its range by using full throttle on smallest cog.

 

[Zimmerframe]

The sound is like a 2 teeth on two cogs grinding each other,

It's an 11 speed chain also ?

Is the derailleur adjusted correctly and the chain the correct length ?

 

[steve_sordy]

............. i tested using full boost mode without pedal assist, .............

I don't understand that phrase. All legal ebikes are pedal assist.

 

[Zimmerframe]

I don't understand that phrase. All legal ebikes are pedal assist.

They're developing their own new e-bikes for unknown markets.

 

[steve_sordy]

They're developing their own new e-bikes for unknown markets.

That is probably half true. I just don't know which half.

 

[Brian J]

okay, " without pedal assist " means i didn't pedal along in the test, throttle power boost was used as the only power source,

 

[Zimmerframe]

It's an 11 speed chain also ?

Is the derailleur adjusted correctly and the chain the correct length ?

Assuming it's not either of these ? and you've eliminated the motor ? then it could be a physical design issue ?

The brake hose and gear cable both exit the top tube in a straight line to the top of the rear triangle.

As the suspension compresses, it will try to compress/shorten both of these. So you might find that moving your own body, or slight bumps is influencing the derailleur cable and causing it to hover between gears. Just the suspension SAG from getting on the bike could be re-adjusting the cable tension.

If you get someone to watch the position of the derailleur whilst you bounce up and down on the bike - does it move from side to side ?

 

[Haedesz]

To be fair, I really want to help but I fear we'll keep guessing for the problem until eternity.

If more bikes have the same problem when tested, it will probably be :
1) bad intrinsic design as mentioned
2) bad setup or building errors
3) wrong components used

I would suggest going back to the manufacturer or bike builder and ask them to check the bike for problems.

Good luck

 

[Webike]

That Top Tube looks like a MANHOOD BUSTER! OUCH...
Bikes with the one-hump camel design should come with a "cup".

 

[Mad Mark]

I don’t understand any of the things he has said.....so I will just say WOW

 

[Jamy]

is this a throttle assist bike or a pedal assist or both

 

[steve_sordy]

is this a throttle assist bike or a pedal assist or both

It must be both or his comments make no sense.

 

[Slowroller]

All the chinese ebikes with Bafang engines come with throttles.

 

[Brian J]

Today i tried riding this E-MTB again, I still heard the big noise whenever i used the smallest cog or sprocket on the cassette, at the same time i was using almost full throttle, was not pedalling, when i heard the noise, the speed was over 50KM/H,
I dind't hear any noise when i the gear was not on the smallest cog or sprocket of the cassette, i have this noise issue with the smallest cog, the cassette is 11 cogs,
whats the problem ?

 

[Zimmerframe]

whats the problem ?

Well this is disappointing. If this is how you trace faults .... then maybe you are the problem ..

Suggestions have been made and questions have been asked to help you determine what the problem might be.

You haven't answered any of them.

So saying the same thing again and not providing any further information, images or answers to previous questions, and then asking "what is the problem" - will not lead to an answer.

Maybe just type the question into @net wurker 's suggestion here : Talk to Transformer

 

[Haedesz]

Business model designed to fail...

 

[Brian J]

Well this is disappointing. If this is how you trace faults .... then maybe you are the problem ..

Suggestions have been made and questions have been asked to help you determine what the problem might be.

You haven't answered any of them.

So saying the same thing again and not providing any further information, images or answers to previous questions, and then asking "what is the problem" - will not lead to an answer.

Maybe just type the question into @net wurker 's suggestion here : Talk to Transformer

Well i think your eyes is inside your ass, thats why you didn't see my answers, right, ?

 

[Brian J]