Rockrider E-st 900 changes upgrades

luckyOne

Member
Sep 1, 2020
8
6
Europe
Yes, it's on the left side, so cars see it better. And it's quite cheap, even original in local shop costs about 10€.

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DT36

Member
Sep 17, 2020
73
69
S. Wales
Loving this thread.
Have recently got back into cycling and was struggling on my Normally Aspirated Mountain Bike (52 year old), so purchased a Rockrider eST900. This has now opened up so many more routes for myself and am really enjoying riding again.

Also purchased a 38T Chainring, from reading this thread, as 50% of my riding is on country roads. My current 32T chainring is maxing out at about 22MPH. I want to continue riding as the wetter winter starts to come in, so will then be doing mostly road rides.

Went to change it last Saturday to do a comparison ride the following day, but failed due to not having the correct tool for the Chainring Bolts. Is this a simple task with the correct tool/spanner?

Having now seen your mod to the stem clamp, I may also consider this. I purchased a Medium frame according to the chart, but think I could have gotten away with a small at 5' 7".

Please keep the updates and modifications coming. (y)
 

BeBiker

Active member
Aug 26, 2020
700
421
Belgium
Hey, thanks for the reply, I see you enjoy the same bike a lot.

The 4 chainring bolts are Allen-key 5mm. That's all you need. Maybe a small rubber hammer or very small wood block.

I discovered the presence of the derailleur-clutch.
It's a small lever on the derailleur and when you engage it, pulling the chain gets a lot easyer.
 

DT36

Member
Sep 17, 2020
73
69
S. Wales
Hey, thanks for the reply, I see you enjoy the same bike a lot.

The 4 chainring bolts are Allen-key 5mm. That's all you need. Maybe a small rubber hammer or very small wood block.

I discovered the presence of the derailleur-clutch.
It's a small lever on the derailleur and when you engage it, pulling the chain gets a lot easyer.

Hi BeBiker,

Thanks for the reply.

The issue I had with the Chainring Bolts was the captive nut on the rear. Basically, when putting the Allen key in the bolt, the rear was spinning. This is a circular captive nut on mine with two small cutouts.
I guess I need to buy a small spanner or tool for this.

I think the 38T Chainring will be better for winter road riding, so looking forward to how you are getting on with it.

 

BeBiker

Active member
Aug 26, 2020
700
421
Belgium
Indeed the back on mine were somewhat spinning too. But touching them with a finger held them while rotating the front, not much space in there !
 

The Old Gaffer

New Member
Oct 12, 2020
1
0
Lincolnshire

BeBiker

Active member
Aug 26, 2020
700
421
Belgium
That's the one that is already on the bike, it goes from Motor to the HMI, with the usb charger port etc.
 
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DT36

Member
Sep 17, 2020
73
69
S. Wales
Just noticed a big price hike on these in Decathlon UK store. Now £1999.99
Been trying (unsuccessfully) for a few weeks to get a Small frame Women's E-ST900 for my wife, as she's been riding my Medium and really likes it. This has put me back on my normally aspirated MTB though when we're out together :)
I may have to cough out a touch more though if they remain out of stock in the Small and go for a Haibike from Tredz in Swansea.
 

DT36

Member
Sep 17, 2020
73
69
S. Wales
No Haibikes available in small size anywhere and pre order delivery is August 2021.
Logged onto Decathlon store this morning and they had a small size Rockrider E-ST520. Just bought it, so waiting on delivery now.
I think the small will be spot on for her, as she manages Ok on my medium E-ST900. Frames are basically the same, just the components are a slightly lower grade.
 

RonnieX

Member
Jul 3, 2020
90
77
Northwest
This Winter I’ve swapped my tyres over to Continental Cross Kings, still kept 2.8 width as I often ride up and down the beach.

I’ve had my first attempt at going tubeless which, 30 miles later, seems to be working well.

I’ve swapped the chainring over to 38t. This has made a noticeable difference.

Adding a beavertail rear mudguard and a crud XL front fender has afforded me and my bike some protection!
 

BeBiker

Active member
Aug 26, 2020
700
421
Belgium
Maxxis Rekon+ 27.5+ 2.8 Skinwall
 

Gary Davis

Member
Feb 13, 2021
138
79
Belgium
Hi,
Has anyone ever thought about replacing Tektro brakes with shimano ones ? The BR-6120 seems to be the best value for money but I wonder if there is enough room for a 4 piston caliper for the rear one due to the shape of the down tube. I really like this bike.
 

Gary Davis

Member
Feb 13, 2021
138
79
Belgium
@Gary Davis
you'll find my mods (xt..)
Sorry, it seems I "skip" the brakes among your modifications. Do you confirm your xp at the rear are the 4 piston series ?
I would also have liked an additional 29 "road" wheelset with thinner tires to keep the same circumference but the swingarm is too short. That's why there no "switch and ride" option for this bike at D4.
 

DT36

Member
Sep 17, 2020
73
69
S. Wales
Think most of my little tweaks/mods are now done. List to date is: Ergon Saddle, Raceface Ride Pedals, Deathgrips, 38t Chain Ring, Maxxis Ardent Tubeless Tyres and finally a RockShoxs QR Front Maxle.
I can now fit the bike in the back of the car much easier that the front wheel will quickly come off. Previously I had to loosen the handlebars and put a blanket up against my front seats for the wheel to sit on. That's in a VW Tiguan which is fairly roomy with the seats down.
Also, the tyres are smaller at 27.5 x 2.40 and now fit better in my wall mount. The bracket was fairly tight before, but plenty of room now. Not taken them up the top of the Valley and forest trail yet, but they seem to roll nice on the road, albeit ever so slightly louder than the Hutchinsons.

38t Chain Ring is also so much better when riding on open roads, as it does not max out at 22mph anymore.

I'll report back on the tyres soon, as the snow and ice seems to be behind us now and hopefully get out this weekend with the Wife on her shiny new E_ST520. Hopefully I'll be able to keep up with her... :)

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BeBiker

Active member
Aug 26, 2020
700
421
Belgium
Nice modifications !

... the tyres are smaller at 27.5 x 2.40 and now fit better in...

Good you talk about this.
I don't really understand those 27.5x2.8.
When not fully inflated they swing the whole bike from left to right, and when fully inflated, why not just use 29x2.20 or 27.5x2.20 ?

I think about changing to 2.20 2.30 2.40 too...
 

Gary Davis

Member
Feb 13, 2021
138
79
Belgium
Nice modifications !



Good you talk about this.
I don't really understand those 27.5x2.8.
When not fully inflated they swing the whole bike from left to right, and when fully inflated, why not just use 29x2.20 or 27.5x2.20 ?

I think about changing to 2.20 2.30 2.40 too...
You are right about those 2.8 but be careful with too narrow tyres because the lowest limit width for the rim is about 60 ERTRO. I really regret that the swing arm is about 1cm too short because two narrower 29 rims would have been perfect for more rolling terrain.
 

BeBiker

Active member
Aug 26, 2020
700
421
Belgium
29" would have been nice, but 27,5 with smaller tyres will also lower the bike a little.
In my case the upper bar is a little above ball-height, every millimeter counts :)
 

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