Rockrider E-st 900 changes upgrades

Glamavia

New Member
Jun 11, 2021
9
0
Bulgaria
Strange event, that oil, and stange logic they brew on that...
I think that the idea was to stall me and pass the bicycle to guys that know what to do. I hope they fix it. About the smell, i didnt get anything. Oil=brake fluid. The guy tried to tell me that the brakes needed bleeding and the disc was contaminated when the bike was assembled. It was funny conversation. I service all my family bikes (cable to hydraulic conversion, new discs, change of brake pads, bleeding, etc.) and i know when somebody lies to me or is extremely incompetent and lies because dont know what to do.
@BeBiker it is possible, i ordered it at the store and if the bike doesent fit me i was able to refuse it. Maybe thats the case.
 

BeBiker

Active member
Aug 26, 2020
700
421
Belgium
Same situation in my local shop. One guy is very competent, another one is a good follower, but the rest is between useless and clueless.
We need a rating system with their names :)
 

BeBiker

Active member
Aug 26, 2020
700
421
Belgium
Little update: Shimano EH500 (Hybrid Semi) Click pedals and Shimano SH-XC300 shoes.

"You don't need that on a E-mtb" is true, but being fixed on the bike, I enjoy better manoeuvres, jumps,...

I always had size 43, but here size 43+ and 44+ were too small.
The size 45 fits good.

Don't forget one pedal has left tread !
 

Gary Davis

Member
Feb 13, 2021
138
79
Belgium
Little update: Shimano EH500 (Hybrid Semi) Click pedals and Shimano SH-XC300 shoes.

"You don't need that on a E-mtb" is true, but being fixed on the bike, I enjoy better manoeuvres, jumps,...

I always had size 43, but here size 43+ and 44+ were too small.
The size 45 fits good.

Don't forget one pedal has left tread !
I'm very satisfied with this combo
Shimano SAINT PD-M820
Shimano SH-AM9N
and you're absolutely right about shimano shoes sizing. Always +1 or +2.
 

BeBiker

Active member
Aug 26, 2020
700
421
Belgium
Another modification today: 203mm rotor + adaptor

20210622_111031rs.jpg
 
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BeBiker

Active member
Aug 26, 2020
700
421
Belgium
What I learnt is that there are 2 major brake caliper mounting systems: PM and IS.
It's the orientation of the holes to fix the caliper.

Our bikes have the Rockshox fork, with PM at the front. (bolts parallel to the wheel, tangential)
The back is IS (bolts going towards the wheel, axial)

Now our Rockshox fork has a PM mount for 160mm disks.
That's why there's already an adapter (160 to 180mm) between the fork and the caliper to fit our 180mm disks.
The names used are often PM160, PM180, PM203, where PM without number stands for PM160.

To fit the 203mm disk, you can choose to fit a second adapter (PM180 to PM203)
or to replace the original (PM160 to PM180) by a new one (PM160 to PM203)

The result is this one: PM-PM-F/R203 (product name AP002 here)

The adapter isn't very much higher as the original one, but has a bolts hole offset that moves the caliper tangential.
Fits perfectly!
There are 2 bolts in the pack, but you need 2 extra M6 30mm bolts, our original ones are too long.

This is the disk. I chose Tektro because the original one has that name too, and works good.

The name of the product was tr203-8, but the picture was tr203-24.
What I received is tr203-24.
I don't know the performance difference, looks OK.
 
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BeBiker

Active member
Aug 26, 2020
700
421
Belgium
Last edited:

Gary Davis

Member
Feb 13, 2021
138
79
Belgium
To be continued,... this is an image of our original IS to PM adapter at the back:

View attachment 64905

And this is an adapter that could fit: PM-IS-R203
View attachment 64906

Let's spend another 20euro
That's exactly what I did
2 Formula brake rotors 203 + adapters
2 Shimano brake calipers 6120 4 pistons
Huge braking difference !
 

BeBiker

Active member
Aug 26, 2020
700
421
Belgium
Did you only change the calipers, or also the tubes and brake levers ?

I guess going from 2 to 4 pistons must be worth it.
 
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Gary Davis

Member
Feb 13, 2021
138
79
Belgium
Did you only change the calipers, or also the tubes and brake handles ?

I guess going from 2 to 4 pistons must be worth it.
I bought the complete kit for 140€ . This was the best value for the money in the 4 pistons range. Indeed. The difference between 2 and 4 pistons is really noticeable.
 

BeBiker

Active member
Aug 26, 2020
700
421
Belgium
Is it this? 171.84eur at the moment...

did installing and bleeding go well?
 
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BeBiker

Active member
Aug 26, 2020
700
421
Belgium
Some may remember Page1 where I was trying other chainrings.
The original 34t is definitively too short, 42t is the maximum but the chainguide doesn't fit, so I installed 38t.

Now I ordered this, and installed the 42t chainring again.

Screenshot 2021-06-23 104435.jpg


Forget about the metal parts, I took the plastic part and grinded some material away at an angle.
20210622_164953rs.jpg


Fits on the 42t, +1mm air everywhere !
The bolt is the one in the box of the new chainguide, fits perfect.
20210622_165939rs.jpg


Here you see why I grinded material away at an angle at the chainguide..
It's the angle of the bike's plastic housing, even with the bolt somewhat loose, it won't fall.
20210622_165902rs.jpg


My chain is worn after 2300km. I will replace:
-the chain by a longer one
-the (somewhat used) 38t chainring by this (nearly new) 42t chainring
-the 11-42t cassette by at 11-50t cassette.

Our Shimano Deore M6000 SG derailleur with medium cage (90mm) has a capacity of 41t, 50-11=39t, so that must fit.
The derailleur fits for max 42t (Low sprocket_Max), but let's try to make it fit 50t with a hanger.

Specs of our derailleur:
 
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DT36

Member
Sep 17, 2020
73
69
S. Wales
I have the 38T installed on mine, following on from your original recommendation. Definitely an improvement, as gone from maxxing out at 22mph to 27mph now.
At what speed to you turn into a demented newspaper delivery boy at with the 42T?
 

BeBiker

Active member
Aug 26, 2020
700
421
Belgium
What I intend to do with the 42t isn't really increasing top speed, but lowering cadance at my current top speed.
10s is way too much for an Emtb, so I'll use the 11t as an overdrive :)

Future, compared to my current 38t setup:
(50/42) * (38/42) -1 = 7,7% shorter shortest gear ratio
(11/11) * (38/42) -1 = 9.5% longer longest gear ratio
...................................................\_--> more spread

Future, compared to the original 34t setup:
(50/42) * (34/42) -1 = 9,6% shorter shortest gear ratio
(11/11) * (34/42) -1 = 8.1% longer longest gear ratio

My current 38t compared to the original setup:
(42/42) * (34/38) -1 = 8.9% longer shortest gear ratio
(11/11) * (34/38) -1 = 8.9% longer longest gear ratio
...................................................\_--> only longer

With the 42t chainring, and the 11-42t cassette, the shortest gear ratio became a bit too long for steep climbs.
 
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Gary Davis

Member
Feb 13, 2021
138
79
Belgium
Is it this? 171.84eur at the moment...

did installing and bleeding go well?
Yes, that's the one. The problem even when I bought it was the availability because of the quite low price and the features offered. Due to the new shape of the mounting bracket of the brake lever it could be difficult to find the right place for the display. I will try to post images to be more precise. The braking modulation is great and the power braking is amazing even with resin pads. Concerning bleeding. No problem. I tried to keep the caliper (mostly the rear one) at the lowest point to avoid bubbles.
 
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Gary Davis

Member
Feb 13, 2021
138
79
Belgium
Some may remember Page1 where I was trying other chainrings.
The original 34t is definitively too short, 42t is the maximum but the chainguide doesn't fit, so I installed 38t.

Now I ordered this, and installed the 42t chainring again.

View attachment 64996

Forget about the metal parts, I took the plastic part and grinded some material away at an angle.
View attachment 64997

Fits on the 42t, +1mm air everywhere !
The bolt is the one in the box of the new chainguide, fits perfect.
View attachment 64998

Here you see why I grinded material away at an angle at the chainguide..
It's the angle of the bike's plastic housing, even with the bolt somewhat loose, it won't fall.
View attachment 64999

My chain is worn after 2300km. I will replace:
-the chain by a longer one
-the (somewhat used) 38t chainring by this (nearly new) 42t chainring
-the 11-42t cassette by at 11-50t cassette.

Our Shimano Deore M6000 SG derailleur with medium cage (90mm) has a capacity of 41t, 50-11=39t, so that must fit.
The derailleur fits for max 42t (Low sprocket_Max), but let's try to make it fit 50t with a hanger.

Specs of our derailleur:
Did you really had the use of a 50t sprocket ?
 

Gary Davis

Member
Feb 13, 2021
138
79
Belgium
Some may remember Page1 where I was trying other chainrings.
The original 34t is definitively too short, 42t is the maximum but the chainguide doesn't fit, so I installed 38t.

Now I ordered this, and installed the 42t chainring again.

View attachment 64996

Forget about the metal parts, I took the plastic part and grinded some material away at an angle.
View attachment 64997

Fits on the 42t, +1mm air everywhere !
The bolt is the one in the box of the new chainguide, fits perfect.
View attachment 64998

Here you see why I grinded material away at an angle at the chainguide..
It's the angle of the bike's plastic housing, even with the bolt somewhat loose, it won't fall.
View attachment 64999

My chain is worn after 2300km. I will replace:
-the chain by a longer one
-the (somewhat used) 38t chainring by this (nearly new) 42t chainring
-the 11-42t cassette by at 11-50t cassette.

Our Shimano Deore M6000 SG derailleur with medium cage (90mm) has a capacity of 41t, 50-11=39t, so that must fit.
The derailleur fits for max 42t (Low sprocket_Max), but let's try to make it fit 50t with a hanger.

Specs of our derailleur:
I also wanted to put a 42 chainring but I found then easier to modify the inner metal support of the chainguide and to grind a bit of plastic of the carter to increase the range of the original chainguide settings. Anyway. As always, you found the way to upgrade your bike and our mechanical experience. Thanks, once again.
By the way. Did you find your new longer chain already ?
 

BeBiker

Active member
Aug 26, 2020
700
421
Belgium
...I found then easier to modify the inner metal support of the chainguide and to grind a bit of plastic of the carter to increase the range of the original chainguide settings...
I never opened that case.
Can you post some images, because the original chainguide looks a bit more stable than the Aliexpress part.
 

Gary Davis

Member
Feb 13, 2021
138
79
Belgium
Here are some images of my bike
I want to increase the spread. Original Shimano it's 11-42t.
So going to 11-46t 11-50t or 11-51t are the possibilities.

Are there problems with the 50t ?
Not at all. I forgot that you have sometimes a trailer. an hanger. Is that the metal piece that it's fixed between the axle and the derailleur to increase his amplitude ? I read on aliexpress some negative comments about this.
 

BeBiker

Active member
Aug 26, 2020
700
421
Belgium
This could work?
126 links, the original is 114 I think.

 

Gary Davis

Member
Feb 13, 2021
138
79
Belgium
I never opened that case.
Can you post some images, because the original chainguide looks a bit more stable than the Aliexpress part.
I didn't put the 42t yet but when I put the 38t I
This could work?
126 links, the original is 114 I think.

I think so. Anyway, they make any problems if you're not satisfied.
 

Gary Davis

Member
Feb 13, 2021
138
79
Belgium
I never opened that case.
Can you post some images, because the original chainguide looks a bit more stable than the Aliexpress part.
Oups ! I didn't put the 42t yet but when I put the 38t I noticed that there was a square metal plate inside the carter who "slide" in a certain range. If you grind the plastic stop and a bit of the carter then you can increase the range of the chainguide.
 

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