Author Topic: FS830 Enduro Frame - Stef Biggel’s build  (Read 9329 times)

JJJ

FS830 pivot design
« Reply #15 on: January 24, 2022, 04:30:36 AM »
A lot of people, including me, was wondering how the links are designed and where the Bearings are build in.

Now its clear, they put the bearings left and right into the Frame and smash it with a throw axel. The head of the axel is conical, so there ist a very stabel centric conection:



OK, so regarding the questions I had about the pivot design, contrary to what I assumed earlier, the bearings are in the frame. So it's this type of pivot:



The link eyelets have shoulders that press on the inner races (directly or through shims that compensate the axial clearance). There doesn't seem to be a spacer inside the frame between the inner races. This means that if you torque the bolts too tight, the eyelets will flex inward and push the inner races inwards, crushing the balls :o This is not a great pivot design, sorry to say Stef, but it's no worse than the AM831 pivot between the lower link and the front triangle. So extra care should be taken to not overtorque the bolts (and maybe the 15 Nm specs are already excessive...).

I'm not sure why they chose a conical bolt head.

graved1gger

Re: FS830 Enduro Frame - Stef Biggel’s build
« Reply #16 on: January 24, 2022, 10:54:23 AM »
There doesn't seem to be a spacer inside the frame between the inner races. This means that if you torque the bolts too tight, the eyelets will flex inward and push the inner races inwards, crushing the balls :o This is not a great pivot design
Indeed, not a great design, though as far as I know this is quite common and even for some brand frames. One local mechanic has been ranting about this for years now :D And in extreme cases he usually machines spacers to remedy this.

I'm almost sold on fs830, but I'll wait for Stef to post some after ride reports :)

JJJ

Re: FS830 Enduro Frame - Stef Biggel’s build
« Reply #17 on: January 24, 2022, 11:39:40 AM »
Indeed, not a great design, though as far as I know this is quite common and even for some brand frames.

Brand frames? Which ones? Not the few I've looked at lately.

Stef Biggel

Re: FS830 Enduro Frame - Stef Biggel’s build
« Reply #18 on: January 24, 2022, 01:00:55 PM »
I'm almost sold on fs830, but I'll wait for Stef to post some after ride reports :)

But you know it‘s winter here in south germany  ;) ?

Stef Biggel

Re: FS830 pivot design
« Reply #19 on: January 24, 2022, 01:08:29 PM »
…., the eyelets will flex inward and push the inner races inwards, crushing the balls :o This is not a great pivot design, sorry to say Stef, but it's no worse than the AM831 pivot between the lower link and the front triangle. So extra care should be taken to not overtorque the bolts (and maybe the 15 Nm specs are already excessive...).

I'm not sure why they chose a conical bolt head.

Ok, thanks to you. I have torque with exact 15Nm and glue it with locktide medium.
If i have to remove the maybe defect bearing when a few rides are over and it's feel not good with the bearing i will fit in a Spacer tube in correct length.

endo.alley

Re: FS830 Enduro Frame - Stef Biggel’s build
« Reply #20 on: January 24, 2022, 01:13:12 PM »
But you know it‘s winter here in south germany  ;) ?

Road trip!

Stef Biggel

Re: FS830 Enduro Frame - Stef Biggel’s build
« Reply #21 on: January 24, 2022, 02:14:20 PM »
Road trip!

I will do my very very best  ;).

JJJ

Re: FS830 pivot design
« Reply #22 on: January 25, 2022, 02:32:21 AM »
Ok, thanks to you. I have torque with exact 15Nm and glue it with locktide medium.
If i have to remove the maybe defect bearing when a few rides are over and it's feel not good with the bearing i will fit in a Spacer tube in correct length.

Ah, well, the bearings were maybe already damaged because the bolt was overtorqued!

Stef Biggel

Re: FS830 pivot design
« Reply #23 on: January 25, 2022, 02:37:08 AM »
Ah, well, the bearings were maybe already damaged because the bolt was overtorqued!

Yes this is a very possible szenario why the bearing sounds so strange by rotating.
« Last Edit: January 25, 2022, 03:29:55 AM by Stef Biggel »

JJJ

Re: FS830 pivot design
« Reply #24 on: January 26, 2022, 02:21:14 AM »
Yes this is a very possible szenario why the bearing sounds so strange by rotating.

Try tightening the bolt on the links removed and check if the eyelets flex inwards before you reach the torque spec - if this is the case, upon final mounting, you should insert a 0.1 mm shim (or less!) in the clearance and stop tightening the bolt as soon as the shim no longer moves freely.

Stef Biggel

Re: FS830 pivot design
« Reply #25 on: January 26, 2022, 12:34:30 PM »
Try tightening the bolt on the links removed and check if the eyelets flex inwards before you reach the torque spec - if this is the case, upon final mounting, you should insert a 0.1 mm shim (or less!) in the clearance and stop tightening the bolt as soon as the shim no longer moves freely.

I will try, thx

Stef Biggel

Re: FS830 Enduro Frame - Stef Biggel’s build
« Reply #26 on: January 27, 2022, 11:07:58 AM »
Ok folks,
Before the weather becomes bad, I’ve done a testing drive with the new FS830. For my opinion it works fantastic, but you must understand I came from a XC bike with only 120 mm travel.
I ride a really short home trail behind my house, only a half of an hour with a few short steep hill climbs, a few little jumps and some steep and narrow curves … and it feels really great. Detecting no loose rear or things like that. Very direct reaction, climbs as well as my xc and it decent as the hell. It feels a little bit like the SC nomad from a friend of me.

So hopefully this helps the guys who are interested in the frame and I will give more experience when I’ve done longer rides.
« Last Edit: January 27, 2022, 01:01:48 PM by Stef Biggel »

Stef Biggel

Re: FS830 Enduro Frame - Stef Biggel’s build
« Reply #27 on: January 27, 2022, 01:57:17 PM »
I took a luggage scale and checked the wight:

It’s 14,4 kg for a 170mm/160mm Travel Enduro Build don’t forget the Kenda & Pirelli tires are not the lightest ones. Not too bad.


Stef Biggel

Re: FS830 Enduro Frame - Stef Biggel’s build
« Reply #28 on: January 30, 2022, 12:06:00 PM »
I had a longer ride today round the valley. This means 600 meter hight up and down. Unfortunately last night the weather was rainy. So all the bottom was defrosted and become very muddy. In this case we wasn’t to fast in descent.

A smile is still in my face. The bike works great. Riding over root-carpet damps great, slowly drive over Steps works good, i think its really direct to drive on narrow curves (hair needle). And i’m really surprised how good it is uphill, i haven't expected. There is nearly no bobbing in the rear. So it wasn't necessary to block the Dampers this ride.

I’m 176cm and the 17” frame fits perfect to me.

So my experience with this longer ride is, that the Link elements works fine and the rear weel is relativ stable by pushing it left and right by hand.

For torquing the link i used the method that JJJ has suggested a view posts before.
 





« Last Edit: January 30, 2022, 12:41:49 PM by Stef Biggel »

zooky

Re: FS830 Enduro Frame - Stef Biggel’s build
« Reply #29 on: January 30, 2022, 11:33:55 PM »
Good read!  Thanks for all the updates!  Keep them coming please  :)