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Ican S3 XC Frame

Started by Ben78, March 30, 2021, 04:39:27 PM

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vw155

#45
It is an Universal Derailleur Hanger (UDH). So it is easy to get it as a spare part.

vw155

Maiden voyage completed:  8)

Ben78

Quote from: vw155 on May 26, 2021, 07:47:26 AM
Maiden voyage completed:  8)

Awesome! Did you end up getting a 165x45 shock? No dramas at all?

carbonazza

Quote from: vw155 on May 26, 2021, 07:47:26 AM
Maiden voyage completed:  8)
Lovely !! :D

I would really like to know one day what's behind all these frames. As here, the front is the FM936.
Are they designed by some western brands or Chinese designers ?
Are there many molds and building sites ?
I'm with this for 7 years now, and it is still an opaque cloud.

marcocpl

unfortunately for my frame, it did not come with the mounting hardware for the upper shock mount.
Does anyone hv the precise measurements of it? is it 29mm x M8? thx

vw155

The mounting hardware depends on the shock. If it is SidLuxe you need RockShox 30mm xM8.

vw155

Quote from: Ben78 on May 27, 2021, 08:09:46 PM
Awesome! Did you end up getting a 165x45 shock? No dramas at all?
165x45 works great

vw155

Quote from: marcocpl on June 02, 2021, 06:27:43 AM
unfortunately for my frame, it did not come with the mounting hardware for the upper shock mount.
Does anyone hv the precise measurements of it? is it 29mm x M8? thx

https://r2-bike.com/ROCKSHOX-Daempfer-Fuehrungsbuchsenset-metrisch-8-mm-8x30-mm

marcocpl

Thanks gents. I bought myself a 42.5 fox DPS.
Will post back once I've built it up!

jetpilot

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)

RobertRinAustin

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)

FWIW, I never bottom out my 936 unless I hit a really big drop or jump so no issues for me.

jetpilot

how much do you weight?
How big are these drops/jumps you speak of?

Julian

#57
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.


RobertRinAustin

Quote from: jetpilot on June 11, 2021, 12:30:37 AM
how much do you weight?
How big are these drops/jumps you speak of?
I'm 200 lbs. Takes about 3 ft drop to flat to flat to bottom out.

jetpilot

Awesome Julian!! I was hoping you would do that  ;)
Yes seems they are both good bikes then, the leverage ratio from Carbonda did seem a bit odd but I found it plausible given what I have seen been done in China ("designers" that dont even know how to use the thing they are making, happens in many products).
I actually prefer the FM936 as its lighter and that's kind of the whole point of this bike (I already have a 160mm bruiser), plus flex stays is the new thing right  :P
Can you post the antisquat curve at least for one of the flex points? ("further back" seems like a good middle ground) THANKS!

Quote from: RobertRinAustin on June 11, 2021, 09:08:37 PM
I'm 200 lbs. Takes about 3 ft drop to flat to flat to bottom out.
You are heavy (like me) but 3ft is not that big (maybe for the type of bike), I am hoping I can replace my bruiser on most of my non bike park days and that might include some bigger stuff ;D maybe it will be good if the tokens are maxed out.