Rockrider E-st 900 changes upgrades

BeBiker

Active member
Aug 26, 2020
700
421
Belgium
I don't remember who warned us, and where, about defects in the rear wheel.
(Difficult to search on a smartphone)

For the first time, I made the effort to clean between the spokes :

20220703_142852.jpg


20220703_142906.jpg
 

silles

Member
Mar 5, 2022
48
19
spain
is it just me but
just after 800km the stock rear tire is finished??? 😲 has less than 1 mm depth in the middle.

it wasn't great so will switch to Maxxis.
 

Afc69

Member
Jun 12, 2020
20
1
Aberdeen
Changing the chainring (again)
Original it comes with 34t, then I changed to 42t, here a pic with the new 38t.

The chain guide goes back on, and I have enough spare chain length now.
The guide is now at maximum height in the guide-travel into the plastic cover.

First driving impressions are good.
Compared to the 42t, I have to pedal faster to go top-speed at full electric power (don't need that often)
I have more choice in the shortest gears, useful to climb without elec assistance.

View attachment 39777
Can I just confirm, with the 38T chainring on now, is that the original chain back on again, or the chain you put on when you moved to the 42T chainring?
 

BeBiker

Active member
Aug 26, 2020
700
421
Belgium
The original short 114 link chain went "just" over the 42t-42t with the derailleur nearly at the end.

I see the picture where I had the 38t with the original chain, I drove like that till it was used. So your 38t-42t should also work without problems.

Later I replaced the 11t-42t with a 11t-46t cassette, for those 46t I definitely needed a longer chain now and threw the used original away. 124 or 136 link can be shortened to fit here.
I shortened the chain so that both 38t, 40t, 42t chainrings are possible.
 
Last edited:

Afc69

Member
Jun 12, 2020
20
1
Aberdeen
The original short 114 link chain went "just" over the 42t-42t with the derailleur nearly at the end.

So your 38t-42t should work better, without problems.

I replaced the 11t-42t with a 11t-46t cassette, for those 46t I definitely needed a longer chain now and threw the used original away. 124 or 136 link can be shortened to fit here.

Later I moved to a 38t chainring, with the same longer chain, so I can go back to 42t if I want.
Thanks

From reading thru your thread this morning, it doesn't look like you did the speed hack, is that correct?
 

silles

Member
Mar 5, 2022
48
19
spain
has anyone done a lower leg service on this thing yet?
could someone tell me how much oil is needed for left/right side?
 

Webbo

New Member
Sep 3, 2022
3
0
Uk
Changing the chainring (again)
Original it comes with 34t, then I changed to 42t, here a pic with the new 38t.

The chain guide goes back on, and I have enough spare chain length now.
The guide is now at maximum height in the guide-travel into the plastic cover.

First driving impressions are good.
Compared to the 42t, I have to pedal faster to go top-speed at full electric power (don't need that often)
I have more choice in the shortest gears, useful to climb without elec assistance.

View attachment 39777
great post, can you tell me, when you added the 38T chain link can you still use the orig chain or did you have to get a longer one. I so much want to do this mod . Thanks in advance
 

GBR66

New Member
Mar 6, 2022
22
12
UK
great post, can you tell me, when you added the 38T chain link can you still use the orig chain or did you have to get a longer one. I so much want to do this mod . Thanks in advance
Fitted 38t 1k KM ago - same chain - works perfectly
 

BeBiker

Active member
Aug 26, 2020
700
421
Belgium
And then there was nothing.
Complete darkness.

When pushing the power button, nothing happens.
With the other charged battery, same result, nothing happens.

I will bring the bike to Decathlon tomorrow, I hope it's a quick fix.
 

GBR66

New Member
Mar 6, 2022
22
12
UK
And then there was nothing.
Complete darkness.

When pushing the power button, nothing happens.
With the other charged battery, same result, nothing happens.

I will bring the bike to Decathlon tomorrow, I hope it's a quick fix.
Checked the cable to the controller?
 

BeBiker

Active member
Aug 26, 2020
700
421
Belgium
Checked the cable to the controller?
With the cover open to remove all modifications that could lead to a warranty denial, I checked the connectors and indeed: white occidation marks.
Lubed it, a few times in-out, works again !
Thanks for the suggestion man !

Somehow in this area a lot of dust and humidity accumulate.
20220911_201307.jpg


5-pin hmi connector already lubed, 2-pin speed connector not yet.
20220911_202238.jpg
 
Last edited:

E-MAD MALC

Active member
Subscriber
Nov 16, 2021
404
229
EAST SUSSEX
With the cover open to remove all modifications that could lead to a warranty denial, I checked the connectors and indeed: white occidation marks.
Lubed it, a few times in-out, works again !
Thanks for the suggestion man !

Somehow in this area a lot of dust and humidity accumulate.
View attachment 96979

5-pin hmi connector already lubed, 2-pin speed connector not yet.
View attachment 96981
Some serious crap in there BeBiker
Do you reckon you could do something to stop it getting that filled up with crap
Anyway glad you sorted the problem out matey
 

BeBiker

Active member
Aug 26, 2020
700
421
Belgium
So I showed the bike to the Decathlon guys... ok wheel warranty no problem.
But the wheel was not in stock...so the had to order, I had to wait for a phone call...no phone call. .

So I went back.... Ok we will order...
Then today I got the call and immediately went after the wheel.

They proposed to do the complete swap themselves, but as I converted to Schrader and tubeless, I chose to do it myself.
I just have to return the defective wheel when finished.
 
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BeBiker

Active member
Aug 26, 2020
700
421
Belgium
The 11-46t "SunRace" cassette didn't accept a new chain anymore,
so I put back the old over-used chain to drive the complete combination till the end.

Now the new rear wheel has arrived, it's the ideal moment to also renew the cassette and chain.
A 10sp 11-50t from "SunShine" this time, 28.08eur, 15 days delivery.
The chain is a KMC e10 EPT again from bike24.de, 37.61eur, 136 links



The cassette came with a derailleur hanger extension included,
it's needed because 11-46t is the limit for our Deore derailleur.

This is how it's mounted:
20220925_151210rs.jpg


A complete view:
20220925_151203rs.jpg


From now on I will alter 2 chains for 1 cassette on my bikes.
As it is mounted now (38t <-> 11-50t) the complete chain including Quick-link has 120 links.
 
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BeBiker

Active member
Aug 26, 2020
700
421
Belgium
The 11t <> 13t shifting needed a little finetuning, it wasn't reacting every time to the shifter.
Propably due to the bigger derailleur distance and the unsuited derailleur angle, adjusting is more sensitive.

The front chainring ( >2000 km ) makes a rattling noise under load with the new chain.
Compare the tooth profile difference with the new one I had in stock:
1664967025502.jpeg


Keeping the back nuts in place during mounting:
1664967455234.jpeg


No more rattling noise now.
 
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E-MAD MALC

Active member
Subscriber
Nov 16, 2021
404
229
EAST SUSSEX
With the dropper post completely shifting in, I'm looking for a saddle-double-bars mounted taillight on battery.
Something like this: www.aliexpress.com/item/33044217963.html
There is Rockbros, Newboiler, Xlite, Meroca, Cubelite,... they have auto-on, auto-off, brake light,...

For a system-powered HMI-commanded taillight it should be able to operate on 6V (I think) and without internal battery.
I still have to buy the (expensive) 2-pin Brose-T taillight-cable, and figure out how the signal behaves.
Very sad there is zero specifications and manuals for this.

Is yours mounted on the side ?
 

BeBiker

Active member
Aug 26, 2020
700
421
Belgium
With this 10sp 11-50t china/hyperglide "hg500" system I am completely satisfied.

Somebody has a clue why Shimano had to "invent" the uncompatible Linkglide system (10-speed version)

Doesn't seem lighter, doesn't seem cheaper, the only claims I see are bold, "up to 300% more... improved shifting... " but there isn't a single real comparison to be found.
 

baddon

New Member
Jan 1, 2023
16
4
Near Belfast
Great work postning your progress Bebiker! Had major problems with the casette skipping on both the 11t and 13t replaced that and the chain ring with the 42t you tried yourself and it feels like a new bike. I use mine mainly as a commuter so also got some wide SKS mud guards and the fat rack for the kids.

View attachment 61041
What mudguards please as these looks very good.
 

E-MAD MALC

Active member
Subscriber
Nov 16, 2021
404
229
EAST SUSSEX
What mudguards please as these looks very good.
Is the bike going to be use for commuting and having racks fitted for transporting stuff
Then they look very good
But i bought
Mudd huggers which are basically to try and stop crud getting on you.
I live on an unmade road with potholes full of water they do help
 

baddon

New Member
Jan 1, 2023
16
4
Near Belfast
Is the bike going to be use for commuting and having racks fitted for transporting stuff
Then they look very good
But i bought
Mudd huggers which are basically to try and stop crud getting on you.
I live on an unmade road with potholes full of water they do help
A bit of everything. BUT as I will take bike away when going in caravan I need to stay clean as have to go all weekend with no ability to shower.
 

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