Decathlon Rockrider E-ST900

[E-MAD MALC]

Sorted.....I had been trying to remove the larger headset cover not realising the small rubber cap in the middle.....FFS!! Grips changed, Bars changed from OEM "angled upwards" to "raised then flat" and angled stem.

You Live and learn my friend
You can't know everything that's why these forums exist to help us out

 

[JumperTrumper]

Very pleased with Rockrider E ST 900, have read around on here and used the advice. Wanted an “e-SUV” for up to maybe 20 miles local trips for
shopping, pub runs.etc in a hilly area, have a Nomad (analogue) tourer for when I want to beast myself. Changed chainring to RaceFace 38t, added pannier rack (and panniers I already had), SKS wide mudguards, bar end mirror (I think essential for narrow roads around me) and changed tyres to Schwalbe Super Moto-X. Plus lights and alarm. Best thing was that the tyre change to “road+“ tyres entirely got rid of the annoying metallic, obviously resonance driven, noise that came in at 20kmh+. Second best thing is that the panniers easily fit it a case of 18 cans of beer!!

View attachment 83536

View attachment 83537

View attachment 83538

That's exactly the setup I want!

 

[GBR66]

That's exactly the setup I want!

Added raised bar (no higher than original but flat not angled grips), 90mm 45 degree angled stem, and Ergon MP3 grips, (have MP5’s on my Thorn Nomad tourer). That’s me done for now - not now an MTB but really loving it as tourer/cargo bike and fun for a fitness ride if the bumpy bits are too steep. Can’t fault the E-ST 900 after first 300km….love the motor, almost silent and no “sharp cut off”.

 

[JumperTrumper]

Looks great. I am just about to purchase mine with the intent of making it a base bike for a tourer/light offroader - any suggestions on sizing?

I am 6ft with 32" inside leg so my thoughts were go for a Medium, based on what others have said on here.

 

[GBR66]

Looks great. I am just about to purchase mine with the intent of making it a base bike for a tourer/light offroader - any suggestions on sizing?

I am 6ft with 32" inside leg so my thoughts were go for a Medium, based on what others have said on here.

I am 5’ 11” with 31” leg but have a stiff knee that means I like the saddle slightly higher than “normal” - also have wide shoulders and long arms…..mine is Large. With saddle high it was a bit hard on my hands hence angled stem which has sorted it - distance from centre of BB to centre of grips 87cm as it was on original set-up

 

[E-MAD MALC]

That's exactly the setup I want!

I've put a set of the vittoria mezcal on my bike as these are good for rolling resistance but still need a bit of grip for the unmade roads where I live
But got to say my son is organising a trip to Norway this summer so a set of those Moto X's would be perfect

 

[silles]

anyone else had any issue with the batter key? After the second ride, i can no longer the unlock the battery. The key does not turn whatever I do. I spent like 1 hour at least wiggling, moving, i even push in the pins 1 by 1.

 

[E-MAD MALC]

anyone else had any issue with the batter key? After the second ride, i can no longer the unlock the battery. The key does not turn whatever I do. I spent like 1 hour at least wiggling, moving, i even push in the pins 1 by 1.

Never happened to me
But any issues I've always WhatsApp Decathlon, D4 and they've aways replied promptly if it's a common problem or they haven't got the solution straight away they get back

Best I can help and hope it gets
resolved
Malc

 

[silles]

Never happened to me
But any issues I've always WhatsApp Decathlon, D4 and they've aways replied promptly if it's a common problem or they haven't got the solution straight away they get back

Best I can help and hope it gets
resolved
Malc

thanks will do that, not supper urgent, better to be locked than not

found this on the spanish de site: Bombín Bloqueo + Llaves Batería Externa Rockrider / Riverside

probably the cheapest part of the bike

 

[E-MAD MALC]

thanks will do that, not supper urgent, better to be locked than not

found this on the spanish de site: Bombín Bloqueo + Llaves Batería Externa Rockrider / Riverside

probably the cheapest part of the bike

Well when you eventually get the lock undone I would replace it
Matter of interest have you tried to pull and push the Lever that initially holds the battery in place while trying to turn the key

Also there a you tube channel if you didn't know, here's a vid from it showing you how to install a new lock

 

[silles]

Well when you eventually get the lock undone I would replace it
Matter of interest have you tried to pull and push the Lever that initially holds the battery in place while trying to turn the key

Also there a you tube channel if you didn't know, here's a vid from it showing you how to install a new lock

yep I tried, pull/push/shake/blow, etc

thanks for the video. looks like an easy job... if i ever managed to open it up.

 

[xyra132]

Hi All

I'm very close to pulling the trigger on buying a E-ST 900. Been looking for a bike to use for commuting (7 miles on a gradual uphill all the way, just a bit to much to cycle normally each day with no showers at work) and a bit of fun off road (i've right next door to an offroad centre, which is very steep and I'm a lot less fit than i once was...) and this seems to fit the bill rather nicely!

I'm a shade over 5'7 without shoes so slap bang in the middle of the suggested size for medium, but i've seen quite a few posts suggesting it's too big, so going to go with the small most likely, does this seem sensible? (I currently ride a small Specialized Camber Evo, which is probably very slightly too small, but fits quite well)

Also, which panniers & rack fits the bike? Any suggestions? (ideally not too small)
I'm looking at this or similar for a lock: Evolution 1016 Integrated Chain normally I'm concerned about the weight of these big locks carrying around, but I don't suppose it makes much difference on a bike like this!

Looking forward to joining the emtb community very soon!

Thanks

 

[silles]

Hi All

I'm very close to pulling the trigger on buying a E-ST 900. Been looking for a bike to use for commuting (7 miles on a gradual uphill all the way, just a bit to much to cycle normally each day with no showers at work) and a bit of fun off road (i've right next door to an offroad centre, which is very steep and I'm a lot less fit than i once was...) and this seems to fit the bill rather nicely!

I'm a shade over 5'7 without shoes so slap bang in the middle of the suggested size for medium, but i've seen quite a few posts suggesting it's too big, so going to go with the small most likely, does this seem sensible? (I currently ride a small Specialized Camber Evo, which is probably very slightly too small, but fits quite well)

Also, which panniers & rack fits the bike? Any suggestions? (ideally not too small)
I'm looking at this or similar for a lock: Evolution 1016 Integrated Chain normally I'm concerned about the weight of these big locks carrying around, but I don't suppose it makes much difference on a bike like this!

Looking forward to joining the emtb community very soon!

Thanks

I used this method: Dialing in your bike setup step 1: Make it RAD – Lee Likes Bikes
I'm 180, RAD 81. Went with Medium. which has RAD around 80. Large was 87, so way to big.

Not sure about S. But gotta be less than 80

Best to try in store....

Bear in mind that this bikes have very high standover. With 180 cm I can barely stand without the top-tube touching my sensitive part.

 

[xyra132]

I used this method: Dialing in your bike setup step 1: Make it RAD – Lee Likes Bikes
I'm 180, RAD 81. Went with Medium. which has RAD around 80. Large was 87, so way to big.

Not sure about S. But gotta be less than 80

Best to try in store....

Bear in mind that this bikes have very high standover. With 180 cm I can barely stand without the top-tube touching my sensitive part.

Thank you!

Unfortunately none of these are in store! My RAD is about 76.6, so the small is likely good if the medium is 80.

In theory I think we can roughly calculate the RAD from pythagoras on (Reach + Stem) over (stack). The numbers on the decathlon page give me 78 for the medium (so fairly close to your 80, so i think i'm in the ball park with this formula). The small comes in at 73 using this, so I'm rather in the middle.

Standover height does concern me though so I think small it will be, as I don't want to crossbar strike to easily when offroad!

 

[E-MAD MALC]

Thank you!

Unfortunately none of these are in store! My RAD is about 76.6, so the small is likely good if the medium is 80.

In theory I think we can roughly calculate the RAD from pythagoras on (Reach + Stem) over (stack). The numbers on the decathlon page give me 78 for the medium (so fairly close to your 80, so i think i'm in the ball park with this formula). The small comes in at 73 using this, so I'm rather in the middle.

Standover height does concern me though so I think small it will be, as I don't want to crossbar strike to easily when offroad!

I'm the same height as you I got the medium and swapped out the stem for a 50mm and it's fine for me now also like others on here I've also swapped out the front wheel for a 29er find it a better ride aswell

 

[xyra132]

I'm the same height as you I got the medium and swapped out the stem for a 50mm and it's fine for me now also like others on here I've also swapped out the front wheel for a 29er find it a better ride aswell

Well that throws a spanner in the works! I'm quite short legged (29" trouser), how's the standover height for you?

 

[E-MAD MALC]

Well that throws a spanner in the works! I'm quite short legged (29" trouser), how's the standover height for you?

I'm the the same as you and I find it OK
Must admit I did eventually put a dropper seat post on on the bike to make riding in all conditions a bit easier

 

[E-MAD MALC]

I'd be honest I don't think there a bike off the shelf to suite everyone's needs without a few mods

 

[xyra132]

I'd be honest I don't think there a bike off the shelf to suite everyone's needs without a few mods

Yeh you're quite right. My full suspension is a small and a touch small, and my hardtail medium is a bit big. I think I prefer slightly undersized. It's tough to decide which route to go for fit sometimes, especially when they aren't available to test ride in-store!

 

[xyra132]

Actually, does anyone happen to know what the realistic standover height on the medium or small is?

I'm still quite confused by the sizing numbers on the decathlon website! The reach seems quite small for such a big bike, is the cockpit a bit cramped on these, or is it just a bit more of an upright seating position?

 

[E-MAD MALC]

Actually, does anyone happen to know what the realistic standover height on the medium or small is?

I'm still quite confused by the sizing numbers on the decathlon website! The reach seems quite small for such a big bike, is the cockpit a bit cramped on these, or is it just a bit more of an upright seating position?

Here's a pic of the height on my medium

 

[xyra132]

Here's a pic of the height on my medium

View attachment 85688

Amazing, thank you.

 

[xyra132]

Here's a pic of the height on my medium

View attachment 85688

That is very high! I've compared it to my hardtail MTB which I consider high and that's only 77cm! Much longer reach though, such a dilemma

 

[stonedwolf]

Well, I have an XL Stius and it's too large for me. But it was the XL or nothing. I have the dropper post, but it's fully dropped. Balls on the crossbar is touchy toes to the ground. I love riding level trails, high elevation, but downhill I I keep feeling like I'm going to be learning how to do forward flips.

But it's the most comfortable pedalling on a bike I've ever owned... I don't feel cramped, or stretched.

 

[xyra132]

Thanks all. I've ordered the small after comparing geometry with lots of other bikes (and that standover is just to high on the medium!). Can't wait for it to arrive now

 

[silles]

Well when you eventually get the lock undone I would replace it
Matter of interest have you tried to pull and push the Lever that initially holds the battery in place while trying to turn the key

Also there a you tube channel if you didn't know, here's a vid from it showing you how to install a new lock

ok I talked to my local decathlon store... they would need to send the bike back, 2 weeks off ... not an option. it's a joke ...

I ordered a replacement lock.
Just have to pick the lock, how hard can it be.

Looks like there is enough space between the battery and the holder to saw it off, than could take out the battery and just replace the lock.

Could someone tell me what's the red flap thing is made off?

 

[xyra132]

Hi I have bought the st-e520 (I guess it's just a st900 with less battery and maybe torque) but the controller seems to detect the magnet cheat and make the motor stop every 5-10 kilometers, that's after a Brose software update (had I know I would have never let them do it), anyfix or suitable controller/display to replace?

Yep, Brose have blocked it (I heard it stops after 500 revolutions of the pedals, not sure if this is right though). Apparently also logs it on the system if it detects it, so they might use it against warranties etc. There are a variety of gadgets to delimit though (obviously only legal on private land), some clip over the magnet pick up and change the pulses, others connect into the wiring loom in some way. I looked at them and disregarded as I think the temptation to use on the road would be too high. About £140ish i think.

 

[xyra132]

Thanks all. I've ordered the small after comparing geometry with lots of other bikes (and that standover is just to high on the medium!). Can't wait for it to arrive now

Ok, i've had a month and done just over 500km, so thought it was time for my thoughts....

Sizing... definately glad I bought a small, the cross bar gets very intimate with me, and the bottom bracket seems high, I have to have the seat high enough that I can barely touch the ground with the tips of my toes. (I'm 5'6 - I know I said 5'7 before. I got my wife to re-measure me.). My 5'3 wife can't get on the bike at all. I'll measure some of the geometry later thats harder to find details of online. (standover / RAD)

Firstly a few (minor) negatives.

• Stem came a bit loose after about 200km, easy to tighten up though
• Little bit of metalic noise somewhere from the back
• Some noise from the front brake when braking.

However, I adore this bike and am a complete ebike convert now. I've commuted almost every day on it since I've had it. Despite being an avid cyclist I've never managed more than a regular 2 times a weeks in the past on a normal bike.

• Service on pickup from Decathlon was excellent, i ordered it collect and it was all built, tested and ready for me
• Power is brilliant, way smoother and quieter than an Orbea Keram (Bose active iirc) I hired a couple of years ago
• Power cutoff at 25kph is gentle and smooth (not harsh like the orbea)
• Very very quiet. Only get a quiet hum when really working it offroad.
• Power offroad is excellent, makes easy work of the very hilly local offroad centre (QECP in Hampshire)
• Tyres aren't as bad as I expected from some of the reviews I had read
• Came with a different handlebar controller to I had seen - a square full colour one.
• Offroad the climbs are so much fun, picking through technical climbs is just a joy
• Downhills maybe slightly less so, the extra weight means braking earlier and harder
• It's brilliant at hauling loads, I added a set of panniers - using the rack "ELOPS BIKE PANNIER RACK 500 26-28 DISC". I did need to bend/twist some of the fittings in a vice to make them fit nicely on the frame
• Rear frame seems a little short, I have to make sure the panniers are slid back as far as possible on the rack to stop shoe strikes.
• I've hauled all sorts of stuff from ratchet sets to powertools on my commute in the panniers, and not noticed the weight at all on the journey.

My only gripe with it is the weight offroad, when it bounces off something hard it really slams into you, where my 11kg hardtail feels like it bounces off you, on this you bounce off it. Once you get used to hovering off the saddle at speed its fine though. If I bought this as a pure offroad toy I would probably return and get a full suspension - however I mainly wanted it for commuting and carrying stuff in the panniers, which this is perfect for.

Range wise, i'm getting maybe 35 - 40km of more difficult riding with hills, steep offroads etc with around 20% or more battery left. On more gentle rides. I would get way more than that.

Wheel calibration seems a little off. Motor cuts at an indicated 25kph, but GPS speedo claims more like 23 -24 kph. Having said that, I seem to sit closer to an indicated 26kph so perhaps the motor actually starts tapering off at 25kph rather than an actual cut off? (would explain the lack of a harsh cutoff)

Now, it would be perfect if they would increase the legal limit to 20mph...

 

[xyra132]

For reference for anyone looking for it as I couldn't find it. For the Small, the RAD is 74 and the standover height is about 84cm.

 

[RonnieX]

Just washed my bike and noticed that the rear wheel as several fine cracks in the rim around many of the spoke holes. It may be prudent to check yours!

I’m still under warranty so I’ve fired off an email to decathlon to see what they say.