Rockrider E-ST 100 - Complete review after 1000 km

ananga

New Member
Feb 17, 2021
9
6
Italy
Hi all, first of all, sorry for my bad English.

I have bought an E-ST 100 in December. I rode almost 700 km on it, then the shop replaced the bike (derailleur / chain problems - they decided to replace the whole bike), and i'm currently at almost 500 km with the new bike.

First of all, this bike is absolutely NOT good for off road, even light off road. You can only ride on very, very smooth gravel roads. The fork is almost non-existant, the chain is very loose and sometime it drops from the chainring and / or you could have problems in the smaller ratio (eighth speed). The chain line is awful, due to a series of factors (this frame has been designed for a Brose center motor and then re-adapted for hub motor).

These problems were so bad that i gave back my bike and replaced with another one.
The new bike is good enough but the problems resurface if you pedal hard.
If you ride on asphalt or smooth gravel, and if you don't pedal very hard, basically the bike is OK.

Pro:

- very nice looking bike, well finished frame
- honest brakes (they need to be squeezed very hard but they work)
- good battery, well integrated on the frame
- good motor (albeit with a bit "high" gear ratio).

Cons:

-Hideous transmission, unstable and unreliable
-Extremely stiff fork, almost useless
-Lack of high gears (you must pedal like crazy to get 45 km/h downhill)
-Lack of cut-off levers (very unsafe)
-Lack of side stand (very hard to install one)
-Cheap clip-on lights with cheap button cells (not connected with the main battery)
-No USB port
-The speed limiter (25 km/h) has a very invasive and sudden action, the motor could support higher speed, but apparently there's no way to derestrict it
-Power cable runs 1 cm from rear disc brake (very unsafe)
-Horrible seat
-Cheap grips (not durable)
-Cheap tires (extremely easy to puncture)
-No clock on the display
-Display is not easy to use (you must press 10 seconds to reset your trip distance / time etc)

The bike is good if you need a city commuter. But at 1000 euro is not so cheap for what it offers - there are better alternatives. I paid 500 euro with government incentive, so it's OK anyway.
I think that it should be normally priced at not more than 800 euro.

maxresdefault.jpg
 

jerry

Active member
Dec 22, 2018
257
166
Belgium
Many of your "cons" suggest you never meant it to use as a MTB (a side stand??). It's the most entry level of bikes possible, comparable to their EUR 249 entry level analog "mountainbike". Its most expensive component is the battery, there's little to be saved on that, so the price is fair for what you get. Any comparison to high-end bikes is unfair and unjust.
 

Zimmerframe

MUPPET
Subscriber
Jun 12, 2019
13,907
20,614
Brittany, France
Nice review, but I have to agree with @jerry .

It's a €1000 bike. A similar price to just the motor on most mid mounted e-bikes.

The bikes wasn't designed around a mid motor. They developed this bike first and then the mid mounted bike in a similar style.

There are definitely positives and negatives .. The tyres are awful, but they and the bike is mainly sold to people who will ride down simple nice lanes and tracks.

The lights don't connect, but it's nice that D4 include lights in the price - most EMTB's don't come with any lights.

I actually thought the saddle was ok.

The Forks are awful, but to say the bike can't be used off road isn't true. It was actually much better than my musculair hard tail.

I didn't have problems with the gears. I found the brakes were lacking. On the e-st500 (before it was renamed) they were cable operated disks. They might be hydraulic now ?

On the early e-st500, the main problems were water. It would get into the cranks and the battery connections, but they fixed that.

Having the hub motor has advantages and disadvantages. On drops it makes it easier for a beginner with the weight so back so you don't go over the bars. But, with the sharp power delivery and all the weight at the back, on steep climbs the bike flips out really easily.

You say the display is not easy to use, but at least it does have reset functions. Most Specialized bikes don't have a display for example.

Most EMTB's don't have cut off levers. Although the Hub motor decathlon maybe could do with them. The problem is that the "torque" sensor isn't a torque sensor. It just senses when the left pedal comes over the top. Then power is applied - all of the power - and it doesn't stop until it's guessed you've stopped because the pedal hasn't returned to the top. This is quite dangerous on technical terrain, or even going through small gaps/gates.

When I had mine I was really disappointed due to the reliability of the motor/battery. If the bike got wet, you couldn't use it for 2 days. Now that it's fixed, I think it's actually quite a fun little bike for the money. I almost bought one last year just to have as a play bike ..

Capable of going most places, just not as fast or as capable as a mid motored bike.

d4.jpg


You can't just go full speed and jump everything, it's great for leaning and exploring though.

d42.jpg


I did fall off it a lot .. It's not designed for speed !

d43.jpg


Was much more usable with a dropper post.

d44.jpg


It will go pretty much anywhere you would on most EMTB's though if you're trail riding.

d45.jpg
 

BeBiker

Active member
Aug 26, 2020
685
409
Belgium
Hey, nice review !

but...

... the chain is very loose and sometime it drops from the chainring and / or you could have problems in the smaller ratio (eighth speed)
Did you check the derailleur clutch ? (my e-st900 has is, I don't know about yours)
Mine was suddenly disengaged, and it showed the problems you explain.

-Lack of high gears (you must pedal like crazy to get 45 km/h downhill)
I replaced the 34t for a 38t, is that possible on your model ?

-Lack of cut-off levers (very unsafe)
I enjoy braking and pedalling at the same time, can't loose one millisecond :)

.
 

ananga

New Member
Feb 17, 2021
9
6
Italy
Many of your "cons" suggest you never meant it to use as a MTB (a side stand??). It's the most entry level of bikes possible, comparable to their EUR 249 entry level analog "mountainbike". Its most expensive component is the battery, there's little to be saved on that, so the price is fair for what you get. Any comparison to high-end bikes is unfair and unjust.

Considering that the bike is not really able to go offroad (believe me, you will finish either with a stuck chain or with your body still shaking for vibrations), the comparison must be done with citybikes or "city MTBs". So a side stand and cutoff lever are not an unnecessary request.
NCM Prague is a proper example - high torque motor, one cut-off lever, side stand, Schwalbe tires and Shimano Altus with triple chainring (not top notch, but sure better than the awful Decathlon components).

The E-ST 500 is a different animal - better transmission and (if i'm not wrong) a decent fork. Yet it was absolutely unreliable in its first version - a friend of mine returned it several times before being refunded (problems with water and with the torque sensor). The V2 version is much better. And yes, the frame is basically the same for all the versions. Just look at the lower tubes.

I'm fine now with the bike, but it should be sold as a citybike. The E-ST 100 is just a € 200,00 bike with battery and motor (probably they are cheaper than the remaining € 800).
I have also a Rockrider 500, probably it was better to fit it with a central kit. Better result for same or lower price.

IMHO Decathlon sucks about ebikes. Always bad reviews everywhere.
They should stick to normal bikes.
 
Last edited:

BeBiker

Active member
Aug 26, 2020
685
409
Belgium
...IMHO Decathlon sucks about ebikes. Always bad reviews everywhere.
They should stick to normal bikes.
I dont agree with this generalisation.
I think you just had to spend 2000 euro on the e-st900.
With some modifications mine now costs 2500 euro, it's a lot of money, but I see it as the absolute minimum to get something.
 

Zimmerframe

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Subscriber
Jun 12, 2019
13,907
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Brittany, France
It looks like the 500 had the Suntour XTR and the 100 the XTC. To be quite honest, with that level of shock specification, there's not really going to be much difference - they're both going to be awful if you want to do downhill. They're selected to a budget.

Agreed the 100 looks like it has a pretty crappy gear setup, but to be fair for only a few euro's you could change all that to a much better one.

Ultimately, you - or someone, is choosing to spend less to buy a cheaper bike. You can't expect to buy the cheapest EMTB they make and then complain that it doesn't perform as well. For most of the people who want a "relatively" cheap EMTB for plodding along fire roads - it will be perfect.

Yes, the first gen 500 had water in the torque sensor (which isn't a torque sensor) and in the battery mounts, but they upgraded those (there's a thread here about it with copies of the technical documentation about what the changes were. It was awful, but it was their first EMTB, they fixed it or they refunded - you can't say fairer than that.

Most of their bad reviews are from people paying €1000 or €1200 euro's and then complaining that they're not as good as a €5000 emtb.
 

ananga

New Member
Feb 17, 2021
9
6
Italy
I can't remember what the fork was - but it was awful. I think I only saw 60mm of movement out of it at most.

Suntour XTC are quite common choice in the low budget bikes. Basically they are almost like rigid forks - no damping at all.
But if you add a loose chain / derailleur, the result is a total torture. I have owned bottom end bikes with $15 Tourney derailleur and they had at least a proper chain line and proper tension.

I have contacted Decathlon about this technical issue and got no response. Many E-ST 100 have the same problem, but they don't care unless they find a consistent number of complaints. Probably the typical owner of this bike just uses only one gear, so it's pretty obvious that they don't care as long as those "just-rotate-the pedal" owners are glad.

They should advertise this bike to be used ONLY on smooth surfaces. For sure it was not my intention to ride this bike as a DH bike, but you CAN'T advertise a bike as "beginner MTB" if the chain jumps off if you just start to pedal hard.

Anyway, this is my review and my experience was not quite good. That's all.
 

ananga

New Member
Feb 17, 2021
9
6
Italy
Did you check the derailleur clutch ? (my e-st900 has is, I don't know about yours)
Mine was suddenly disengaged, and it showed the problems you explain.

I replaced the 34t for a 38t, is that possible on your model ?

.

Sure, i have a 32t chainring - it's too short gear and it's "domed" towards the frame.
The chain line is completely wrong. See photo.

chainl.jpg


I was thinking to make a slightly better chain line installing a 38t flat chainring, improving the offset.
That's the only solution to avoid problems in 8th gear.
 

BeBiker

Active member
Aug 26, 2020
685
409
Belgium
You show here very good that the frame is derived from a mid-engine, where the pedals are a lot more separated.
And then they installed a "normal" pedal-set
 

ananga

New Member
Feb 17, 2021
9
6
Italy
You show here very good that the frame is derived from a mid-engine, where the pedals are a lot more separated.
And then they installed a "normal" pedal-set

Exactly. And they did not manage to get a decent chain line with only one chainring and 8 speeds.
 

Zimmerframe

MUPPET
Subscriber
Jun 12, 2019
13,907
20,614
Brittany, France
I can understand you being frustrated with the gear issues and the bike not being what you want it to be, but :

I still think you're expecting more from the bike than it's obviously aimed at and even advertised as.

On Decathlon.co.uk :

This electric mountain bike is designed for MTB rides on ROLLING TERRAIN.

On Decathlon.fr

Ce VTT électrique est conçu pour les randonnées TOUT TERRAIN VALLONNEES.

Lets also be clear about the bike. It is NOT a mid motored bike which has been adapted. It's based on the E-ST500 which was developed first. They went on to develop the mid motored bike afterwards using a similar frame style.

All bikes have chainlines where the chain does not stay straight. The gears are all spread over the same area and goto a chainring which is fixed (though sram do have a patent on a pivoting one). Look at any bike and in most gears the chain won't be straight.

The q-factor at the cranks is similar to most EMTB's.

The rear is arguably pushed further out due to having to accommodate a hub motor. Even taking that into account though, the rear axle is a 150*12. If you compare that to my Kenevo, a 148*12 - you're only 2mm wider.

It's unfortunately, because when you buy a relatively cheap EMTB - for some reason everyone expects that you will get on it and it will do what everyone wants without changing anything. If you buy an expensive EMTB, people expect they will have to change things to make it fit with their preferences.

I had a mid motored E8000 bike (Karma) - €3000 and yet it still didn't come with a clutch on the derailleur. Every descent with bumps and you lost the chain. So I bought a derailleur with a clutch.

For you, I would accept that the bike's gears are cheap and not good and just upgrade them. Either buy the same setup as the e-st500, but try to find a derailleur with a clutch. Or upgrade to a 10 speed. It should all fit on your hub.

I have a new 10 speed shimano cassette and chain you're more than welcome to at the other house I can pick up next time I'm there. You'd just need to buy a new 10 speed shifter and ideally an XT deraillier.

Before you do that, check your derailleur b-screw (videos on youtube). This can make a huge difference to shifting.

For the chainring - I don't suppose it's on backwards is it ? and should be domed outwards ?
 

ananga

New Member
Feb 17, 2021
9
6
Italy
I still think you're expecting more from the bike than it's obviously aimed at and even advertised as.

I was fully aware of the limits of the bike, i did not think to buy a Ferrari with €1000.
But i was not aware that the chain was jumping on asphalt in 8th gear every 2 km just pedalling a bit harder.
That chain line is so bad that it makes me think that the E-ST 100 is just a "pout pourri" of parts occasionally found on the market at extremely low price (but , as said, i had Tourney-mounted bikes that worked flawlessy) and put together in bad way.

No need of clutch derailleur and other things, i need to adjust the chain line (they went beyond the acceptable limits). 2 mm would be enough. That means: some sort of spacer, a longer spindle, or a new chainring.

A flat chainring would probably fix everything , but i can't find anything with this center hole (this is the stock chainring).

Miranda-chainring-direct-mount-mtb-2.png
 

Gary

Old Tartan Bollocks
Author
Subscriber
Mar 29, 2018
10,496
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the internet
@Gary Any idea what that chainring fitment is ?
It's a Miranda direct mount standard called XMod
explained here and if you scroll down there's a handy animated exploded view
also they make a direct mount 104BCD spider to fit the crankset

As the bike is rear hub driven it will more than likely have a threaded BSA BB shell so you can just ditch those and fit any decent mtb BB and crankset you want.
for ease of finding cheap NW rings I'd go with something like old 104bcd HTII Deore/SLX/Zee if you can find one anywhere
 

Gary

Old Tartan Bollocks
Author
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Mar 29, 2018
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if your chainline is way off are you sure the chainring was fitted the correct way round?
 

Gary

Old Tartan Bollocks
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Mar 29, 2018
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skim read the thread now

That crankset doesn't even look to have a boost compatible chainline and the rear hub is 150mm OLN
If it indeed is a normal crankset compatible with 135mm QR rear hubs it'll be out by 7.5mm
If the chainring is 3mm offset and it's actually been fitted the wrong way around this would solve the issue.
The addition of a clutch mech would help with chain retention. Especially in the smallest cassette sprockets

Skim read the review as well. what a car crash!
What exactly did you expect for a grand?
 

ggx

Well-known member
Dec 10, 2018
689
443
Sintra
Wife bought one of this for comunting and is happy with it. For heavy dutty another beast in town ☢ :LOL:
 

ananga

New Member
Feb 17, 2021
9
6
Italy
Wrong info, sorry. My fault. The chainring is not an X-Mod. I wrote to Miranda and they said it's a specific chainring in one piece with the crank. Bottom bracket is a square-taper type, the chainring has a sort of spacer (see photo).

What exactly did you expect for a grand?

To pedal strongly in 8th gear without a "crack" (chain trying to jump in 7th) every 1-2 km.
It's not a so big demand.

perno.jpg
 
Last edited:

Gary

Old Tartan Bollocks
Author
Subscriber
Mar 29, 2018
10,496
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the internet
In that case just fit a new square taper BB with a longer axle.
They come in various lengths.
I'd recommend a Shimano UN55 or similar as they tend to last forever.
 

vitorjaneiro

New Member
Aug 31, 2021
1
0
Setubal, Portugal
Hi all, first of all, sorry for my bad English.

I have bought an E-ST 100 in December. I rode almost 700 km on it, then the shop replaced the bike (derailleur / chain problems - they decided to replace the whole bike), and i'm currently at almost 500 km with the new bike.

First of all, this bike is absolutely NOT good for off road, even light off road. You can only ride on very, very smooth gravel roads. The fork is almost non-existant, the chain is very loose and sometime it drops from the chainring and / or you could have problems in the smaller ratio (eighth speed). The chain line is awful, due to a series of factors (this frame has been designed for a Brose center motor and then re-adapted for hub motor).

These problems were so bad that i gave back my bike and replaced with another one.
The new bike is good enough but the problems resurface if you pedal hard.
If you ride on asphalt or smooth gravel, and if you don't pedal very hard, basically the bike is OK.

Pro:

- very nice looking bike, well finished frame
- honest brakes (they need to be squeezed very hard but they work)
- good battery, well integrated on the frame
- good motor (albeit with a bit "high" gear ratio).

Cons:

-Hideous transmission, unstable and unreliable
-Extremely stiff fork, almost useless
-Lack of high gears (you must pedal like crazy to get 45 km/h downhill)
-Lack of cut-off levers (very unsafe)
-Lack of side stand (very hard to install one)
-Cheap clip-on lights with cheap button cells (not connected with the main battery)
-No USB port
-The speed limiter (25 km/h) has a very invasive and sudden action, the motor could support higher speed, but apparently there's no way to derestrict it
-Power cable runs 1 cm from rear disc brake (very unsafe)
-Horrible seat
-Cheap grips (not durable)
-Cheap tires (extremely easy to puncture)
-No clock on the display
-Display is not easy to use (you must press 10 seconds to reset your trip distance / time etc)

The bike is good if you need a city commuter. But at 1000 euro is not so cheap for what it offers - there are better alternatives. I paid 500 euro with government incentive, so it's OK anyway.
I think that it should be normally priced at not more than 800 euro.

View attachment 53310
Ola. é portugues(a)? tinha uma questao : quando refere no apoio , eu tb pedi mas informaram-me (a decathlon) que nao passavam declaração que era feita para cidade, conforme pedido pelo governo... pode ajudar? obrigado desde já...
 

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