Rockrider EST 500 (900) error 70???

[lewislocektt]

Hello. I have recently purchased a second hand rockrider est 500. Great little ebike for commuting to and from work. However, recently I have had issues with a error code 70 displaying on the screen and the pedel assist only occasionally working.

After looking online I can not find what the issue relates to, or how to fix it. Has anyone else had this problem or suggestions? From what I can see it may be something torque sensor related. I'm not sure if this can be unplugged and checked etc..

Any help is appreciated

 

[DT36]

This is all I found:
ERROR 70/71/72/73 = TORQUE SENSOR ERROR Switch off the bike and switch it on again.
If the error code continues to show, go to a Decathlon workshop.

 

[Zimmerframe]

I think it's called an "e-st 500" - if you don't search correctly, you won't get any answers.

I had one a couple of years ago when they first came out. Looking back it was actually an ok bike for what it was .

The main issue then was the torque sensor moisture ingress. Generally, if you left it 48 hours somewhere warm and dry, it would fix itself.

I could be you have a dodgy cable though, or the torque (position) sensor - as it's not really a torque sensor on the e-st500 - it just notes when the left crank goes over top dead centre.

I've attached the Internal Decathlon documents which shows the fixes they did to the bikes at the time. If yours was an early one and it never went back, it wouldn't of had these fixes. They're in French and English, so you should be ok. The crank case is just packing in grease basically.

 

[Tonybro]

I can't offer any specific help but just to be sure - you are not turning the bike one whilst sat on it with a foot on a pedal are you? I did it once on my Merida and it threw up an error message not long after I got it. It was because the sensor thought there was a problem as I was pressing lightly on the pedal as I turned it on. Now I turn it on BEFORE I get on the bike...

 

[lewislocektt]

No I'm not. I'm just turning on and the screen is fine then after 20-30secs if those the error code. Pedestrian mode works fine and the pedel assist does kick In but is temperamental and will just stop ever so often

 

[lewislocektt]

Thanks for the replies. I have left it for 3 days but in my garage. I have brought it in to my back room of my house to try to "warm it up" I will have a read and see what the documents say

 

[The Hodge]

Please check that the rear axle is tightened..I had a similar stop start problem ..which could have led to a pretty serious accident all because the bolt through axle was " loose " ..

 

[lewislocektt]

Please check that the rear axle is tightened..I had a similar stop start problem ..which could have led to a pretty serious accident all because the bolt through axle was " loose " ..

Will give this a look at....looks and feels.tight enough.

 

[lewislocektt]

Still having the problem although it only happening maybe every 3 or 4 times turning on. I opened up the torque sensor casing and used a warm hairdryer fir a short amount of time to try dry out any moisture that is in there....seems to of slightly improves, but would not recommend haha

 

[lewislocektt]

Update for a few days later. No longer getting error 70 displayed, however now the pedal assist kicks in for 2 or 3 rotations and then stops, if I stop peddling and then carry on it will assist again for another 3l2 or 3 rotations.

Anyone have any suggestions. Think I may need to replace the torque sensor but ideally don't want to do this unless it is a must

 

[Zimmerframe]

Part of that might just be down to how the e-st500 works.

Most bikes have a torque sensor, so they detect when and how hard you're pedalling and adjust the assistance accordingly.

Some bikes have some "run over" built in as standard, so the motor will continue to assist for 0.2 of a second or so to help you over a rock when you stop pedalling for instance.

The E-st500 just has a position sensor. You might notice that if you start pedalling with your right foot from the top, you don't get any assistance until it gets to the bottom. Which can be a real pain when starting on steep hills. On mine (they might be different depending how it's installed, I had two and they were both the same though) it picked up when your left pedal started it's downward stroke. So if you hill started with a left foot start, you were ok.

The problem with this is that it doesn't know when you've stopped pedalling until it realises it's not picked up the pedal again - So it just has to presume you are pedalling and keeps providing power for however long it's decided is about the right amount of time. This might be 1-2-3 seconds. Then when that time period has passed and it's not picked up a new pedal rotation, it cuts the power.

It was something you adjusted to over time. You just learnt to stop pedalling slightly sooner than you might - but knowing you'd still have power without having to pedal.

 

[lewislocektt]

Part of that might just be down to how the e-st500 works.

Most bikes have a torque sensor, so they detect when and how hard you're pedalling and adjust the assistance accordingly.

Some bikes have some "run over" built in as standard, so the motor will continue to assist for 0.2 of a second or so to help you over a rock when you stop pedalling for instance.

The E-st500 just has a position sensor. You might notice that if you start pedalling with your right foot from the top, you don't get any assistance until it gets to the bottom. Which can be a real pain when starting on steep hills. On mine (they might be different depending how it's installed, I had two and they were both the same though) it picked up when your left pedal started it's downward stroke. So if you hill started with a left foot start, you were ok.

The problem with this is that it doesn't know when you've stopped pedalling until it realises it's not picked up the pedal again - So it just has to presume you are pedalling and keeps providing power for however long it's decided is about the right amount of time. This might be 1-2-3 seconds. Then when that time period has passed and it's not picked up a new pedal rotation, it cuts the power.

It was something you adjusted to over time. You just learnt to stop pedalling slightly sooner than you might - but knowing you'd still have power without having to pedal.

I used ot this morning commuting to work up a large hill....forst few weeks of use I could always feel the assist and was between 10-13 km, this morning as mentioned it only kicked in for a brief spell and stopped and I was at 6-8 kmh

 

[Zimmerframe]

I used ot this morning commuting to work up a large hill....forst few weeks of use I could always feel the assist and was between 10-13 km, this morning as mentioned it only kicked in for a brief spell and stopped and I was at 6-8 kmh

Ah sorry, I was miss understanding what you were saying.

I think I'd also take the cover off below the battery and check the cables/connections in there (take the battery off first). You can get crap in there which will cause problems.

If that all seems good, then it's looking more and more like your "torque sensor" is faulty.

 

[lewislocektt]

Ah sorry, I was miss understanding what you were saying.

I think I'd also take the cover off below the battery and check the cables/connections in there (take the battery off first). You can get crap in there which will cause problems.

If that all seems good, then it's looking more and more like your "torque sensor" is faulty.

This is my thought. I have a day off on Friday so will take a look in to it. Failing that I will go to store on Monday with jt and hopefully they can replace or check the sensor