See likes

See likes given/taken


Posts you liked

Pages: [1]
Post info No. of Likes
Re: Ican S3 XC Frame
Quote from: jetpilot on June 10, 2021, 10:02:28 PM
Seems like the S3 has a much better suspension design than the FM936.

Attached is the leverage curve sent by Adam at Carbonda and the S3 (thanks Julian)

As you can see the S3 is progressive to linear, similar to most modern XC bikes designed for an air shock

The FM936 has a really pronounced falling rate in the end of travel, this would mean it has very little bottom out resistance. Almost no bikes are designed like this today. We want a rising rate.

I have been looking at these bikes for my next downcountry bike but seems the S3 is a better choice for anyone who will bottom it out. Too bad its heavier than the FM936 by more than 400grs (comparing the SL version)

You're welcome :)

Your analysis is correct, but I'm not sure if you can trust Adam's material. It seems like he's also using X3 to calculate the leverage ratio, but with that software it's absolutely impossible to calculate the actual leverage ratio of the FM936, because it does not have any means to factor in the flexing seat stays. If you only put in the actual existing links, the software will have a calculation error. I'm no engineer, but I'm pretty sure a flexing part does not have one fixed pivot point, but one that moves throughout the bend (similar to a VPP). That's why I have refrained from posting any leverage ratio stuff on the FM936. I've tried to get close to the actual leverage ratio by using a classic swingarm 4-bar design (so one additional pivot point in the seat stays) and placing the rear link pivot in the middle of the seat stay, where it's the most bendy. But placing it there will cause the seatstay to shorten a lot more than the actual bending does. So neither leverage ratio nor actual travel can be properly calculated.

I've tried out various different positions for that rear pivot point and the leverage ratio was always fairly progressive. That is also supported by what NS Bikes claim for the not-so-different Synonym and by what FM936 riders have reported so far. So I believe that the actual leverage ratio is absolutely fine for a down country bike.

I've attached some examples for different pivot placements in the middle and further back as well as one where it pivots around the rear axle. The "truth" could be somewhere between those estimates.


June 11, 2021, 01:30:36 AM 		1
Re: LightCarbon 918? So my frame and wheelset arrived and I have been doing the slow build this week! Ill share a photos later. Frame notes first:

Size Large painted glossy Pantone 624C. Paint is fantastic, not a chip or miss anywhere and the color is perfect.

Seatpost fit is pretty sloppy. Seems a tad over 31.6 mm seat tube bore.I will try a different post, as this fit is with an ebay carbon. I might have to insert a shim of a couple thousandths of an inch to fix this.

Rear Dropout Spacing is a little wide by 3 or 4 mm. Axle pulls gap closed just fine and tightens to torque without issue.

Shock install was no issue and fit perfect.

Left Bottom Bracket threads were a bit of a challenge. I should have chased the threads with a tap but was able to get the cup in straight using the crank axle as a guide and press using an old BB cup and some oil first.

Chainring Clearance: I run a 34t WolfTooth Oval and it clears the lower stay just fine. Not sure on a 36 round, 36 oval would not clear it.

Headset: There is nothing in mountain bikes more stupid than running cables and hoses through the top of the headset. Aesthetic value is Zero. A sharp radius is created in the shift cable hosing to get under my handlebars and to the shifter. I am running only shift and rear brake though the frame. I have one 10mm spacer under my stem. I started with both exiting on the right, toward my shifter and brake lever but that seemed too tight of bend, now have them on the left.

Those that have built one of these- What side did you end up running your right hand controls on?

Cable routing through the frame was nice and smooth with no issues. I did slide foam damper tubes over both inside the main triangle. Headset fitment is nice. I do wish it had 1-1/8th inch upper and normal cable routes exiting on the side for smoother lines and cable actuation though.

Rear brake hose rote is odd, but works. Brake mount will not fit on chain stay location so has to be on upper. I ran brake inside stays and over to the shimano banjo bolt on the outside of the XT brake.

Bottle cage threads are aligned and clean. Large frame size has mounting for 2 bottle cages. The seat tube location WILL fit a cage, BUT a small/ 21oz  bottle will never fit. This would be a good spot for storage in a cage or using a strap like WolfTooth offers instead of H2O.

Oh, did I mention how f#cking stupid 'through headset' cable routing is??

That is all for now!

January 22, 2023, 10:52:01 AM 		1
Re: Carbonda fm936 Thoughts
Quote from: two-one on January 26, 2023, 01:50:23 AM
Awesome!
Can you measure the distance between the rocker-pivot and the other pivots for both?

Clearly it extends the rear wheel further now, so bottomout geometry is the same for both versions.
The tiny bit higher dynamic ride height might be beneficial for this frame, with its low BB and slack headangle.

Rocker pivot to shock pivot 48mm (100mm rocker)
Rocker pivot to shock pivot 49mm (120mm rocker)
Rocker pivot to rear-end pivot 64mm (100mn rocker)
Rocker pivot to rear-end pivot 62mm (120mm rocker)
New 120mm  rocker on the left hand side of the pictures

January 26, 2023, 09:45:29 AM 		1
Re: Carbonda fm936 Thoughts I can confirm that two bottles fit quite well in a large FM936 frame!  Also got a couple other 3D printed bits, the Manitou Mara remote lockout exits on the top (or bottom in the case of this mounting) but there's no room in the frame, so I printed a little sleeve for the aircan with a mount for the cable housing, so it now exits out the non-drive-side.  I just swapped from an LCFS911 to this and carried most of the parts over, but still going to build a new wheelset and get new handlebar/stem.  Once it's all done I'm thinking it'll come in right under 25 lbs.  The trails will be wet until mid March or so, so it'll be a while until a ride report.  So far the geo feels a lot like my Guerrilla Gravity, except it's fast in a straight line like my 911 was.
January 26, 2023, 09:29:59 PM 		1