Carbonda fm936 Thoughts

[Kk5551]

Hey all-  I built up a medium and XL FM936 for my sons last summer.  They were the regular 100mm frame sets which I outfitted with Fox Float DPS 42.5 and Fox 34 120mm.  Both bikes have been amazing and are perfect for the 'Downcountry' riding that we do.

I am looking to build up a size LARGE FM936 for myself and am wondering if I just order the same frame and build it up the same as my other two, or if I give the 120mm frame a shot.

Any additional user experience or advice?  Thanks!

[Arno Knell]

Surely not. 120mm rocker require 120mm fork to set frame into 67 deg HA (as stated in the table below drawing). How come have you got 65.5 if default HA is 67 deg and you haven't risen front wheel? To get 66 deg HA you need about 140mm fork.
EDIT: Indeed, 120mm Fox SC also has 530mm A2C, so with 120/120 setup HA will be about 66.5, but not 65.5, for sure.

I checked the ha with a digital protractor.
i measured 68,6° on my sp-m05 frame with sid sl 100;
fm909 frame 100/100 with sid sl 100 = 66,6° ha;
fm936 frame 120/120 with sid ultimate 120 = 65,5° ha.
I will double check it tomorrow morning.
BB clearance 330mm
PS:
Maybe the carbonda drawing is not correct.

[Eneen]

Please do. But their drawings are projected 3d views so I really doubt that this would be the case...

[volan]

Not to be rude, but those questions are answered a couple of times...use the search option please...
And email carbonda direct instead of alibaba...sometimes cheaper, but always fast reply ( not these days, because of chinese newyear)

Good luck

Sorry, ik. But mere fact there are 150 pages on this sub get me confused

I emailed carbonda, still no reply... But i guess it's the festivities you mentioned the reason for delay.

[Arno Knell]

Please do. But their drawings are projected 3d views so I really doub hat this would be the case...

I measured the ha again.
SP-M05 = 68,6°
FM909 = 66,6°
Jeffsy with 160mm fork  66,1°
Capra with 170mm fork 65,3°
FM936 = 65,8°

[Eneen]

@Arno Knell, 909 HA matches drawing perfectly but I really don't know how come 936 is 65.8...

[Arno Knell]

@Arno Knell, 909 HA matches drawing perfectly but I really don't know how come 936 is 65.8...

That is the reason why i measured all my bikes ha again (twice)
Jeffsy ha is correct.
Capra ha is correct.
SP-M05 ha is correct.
FM909 ha is correct.
So the FM936 120/120 ha should also be correct !

[sync1]

I trust real measurements (from Arno Knell) more than Carbonda.
Thanks for sharing. Can you also get the STA? (real and effective)

[Arno Knell]

I trust real measurements (from Arno Knell) more than Carbonda.
Thanks for sharing. Can you also get the STA? (real and effective)

Following my measurements of the sta
at a seat hight of 735mm:

FM936 actual = 70° virtual = 76°
FM909 actual = 72° virtual = 77,6°
SP-M05 actual = 72° virtual = 74°

[Zomb1e]

One guy on German forum posted this calculation. It's based on real A2C dimensions for 120mm forks instead of weird 520mm in Carbonda's drawing. And even these calculations are closer to Arno Knell measurements than to data provided by Carbonda.

[Eneen]

SA/HA relation is almost same as with drawings: 76/65.8 vs 77/67, 0.2deg difference. So where's en error?
120mm forks clearly have about 530mm, Carbonda spec is for 110 or something like this.

[Zomb1e]

SA/HA relation is almost same as with drawings: 76/65.8 vs 77/67, 0.2deg difference. So where's en error?

67-65.8=0.2? Nice

[Eneen]

76-65.8=10.2
77-67=10
0.2deg difference, I guess close to measuring tolerance.
Rising front by 20mm rotates frame by about 1 deg. Arno has 531mm fork, so front went up about 25mm from default Carbonda spec (506mm). Carbonda replaced only rocker, so maybe rear end wasn't actually risen by 10mm, but only 3-5mm?

[Arno Knell]

76-65.8=10.2
77-67=10
0.2deg difference, I guess close to measuring tolerance.
Rising front by 20mm rotates frame by about 1 deg. Arno has 531mm fork, so front went up about 25mm from default Carbonda spec (506mm). Carbonda replaced only rocker, so maybe rear end wasn't actually risen by 10mm, but only 3-5mm?

On the fm936 frame 120/120mm i measured bb offest -38mm (bb clearance = 330mm).

But i am not sure if the new rocker  really "generate" 120mm rear travel.

[volan]

Guys, thanks for all replies so far. I have one more quibble to solve. Namely, the rear travel. Since I have Sid SL fork which i recently bought for my ht, I'd like to know if I could go fm936 with 120mm rear travel, and pair it with sid sl (100mm)? Would that be a bad setup? I'd like to go 120mm rear travel so i can go 120mm in the future with fork as well, but if 120r/100f would result in too sketchy geo, i'd consider then 100/100 build. Any advice would be appreciated!

ps. i have old 120mm qr markhoor fork that could "do the job" for now. But it's not as stiff nor stable as my new sid, so that's kinda off the table if i would build 120mm for more downcountry/trail oriented ride.

tldr: is 120 rear and 100 front acceptable with fm936?