Carbonda fm936 Thoughts

[qwerty]

Hi, Anyone use a 52mm chain line Shimano crankset (7100 or 8100) with a 32t ring on their frame? Is the clearance OK @ >3mm?

[Jbegs]

Has anyone bent there upper shock mount? I did a search but could find anyone mentioning that. Its very slight so I'm hoping its just a bolt quality issue. All the other bolts in the linkage were torqued properly and no play at the bushing.

If anyone has I could use a link to what you replaced it with.
Thank you

[ilyamaksimov]

Has anyone bent there upper shock mount? I did a search but could find anyone mentioning that. Its very slight so I'm hoping its just a bolt quality issue. All the other bolts in the linkage were torqued properly and no play at the bushing.

If anyone has I could use a link to what you replaced it with.
Thank you

Yes, I also bent a little, I bought a new bolt on aliexpress and everything became fine. Unfortunately the original carbonda bolts are not of very good quality

this bolt, lenght 40mm https://aliexpress.ru/item/32346297012.html?spm=a2g39.orderlist.0.0.626d4aa6Epw2fK&_ga=2.238546816.1248168000.1635175814-2025224587.1629912215&_gac=1.48907732.1633550633.CjwKCAjwkvWKBhB4EiwA-GHjFh1f2ima6Yzra606rzp_VI4RPxiWXupqcG65UfpDAKXqSkqe_XHaIBoCtIkQAvD_BwE

[reddi]

Yes, there is a quality issue with that bolt. I know several FM936 riders whose upper shock bolts were bent, including myself.
Replaced it with this one (40 mm).

[inv]

I am 181cm and 81cm inseam.

What size do you think?  Background: road and a bit XC races

Very primitive calcs:

Top-tube thoughts:
  On my old cannondale flash 29er L-size: 62cm top-tube and ~10cm stem + -2cm offset, so, total saddle-handlebar is ~74cm
  FM936 can have the same 74cm on M (61cm TT) + 2cm off + 11cm stem or L (64cm TT) + 2cm off + 8cm stem

Reach thoughts:
  Cannondale has 42.5cm reach, so looks like FM936 is very long M is 47.5cm and L is 50cm.
  Probably seat-tube angle eats about ~3cm (maybe I am wrong here) and if I remove seatback offset another 2cm, total 5 => 42.5cm or 45cm

Sounds like I have to go for M with long stem, but absolutely not sure, because I am non experienced technical XC racer

Thank you for any advice

--added--
Looks like I calculated tt wrong and fixed it, but still not sure which is better

[carbonazza]

I am 181cm and 81cm inseam.

What size do you think?  Background: road and a bit XC races

Very primitive calcs:

Top-tube thoughts:
  On my old cannondale flash 29er L-size: 62cm top-tube and ~10cm stem, so, total saddle-handlebar it is ~72cm
  FM936 can have the same 72cm on M (61cm) + 11cm stem or L + 8cm stem

Reach thoughts:
  Cannondale has 42.5cm reach, so looks like FM936 is very long M is 47.5cm and L is 50cm.
  Probably seat-tube angle eats about ~3cm (maybe I am wrong here) and if I remove seatback offset another 2cm, total 5 => 42.5cm or 45cm

Sounds like I have to go for M with long stem, but absolutely not sure, because I am non experienced technical XC racer

Thank you for any advice

--added--
Looks like I calculated tt wrong and fixed it, but still not sure which is better

I'm 178cm / 89cm and ride an M with a 65mm stem.
I think a L would have been good too, so probably good for your longer torso, and more in the spirit of the bike.

[inv]

If I summarize all the basic math:

1) most of the droppers does not have offset => saddle moves forward even a bit more
2) The main diff for the frame makes seat-angle and Saddle-BB distance is ~8cm diff from old geometry => it is the ~same diff like Road and TT bike saddle

^^^ all the things are the ~same on M and L frames, so the only important diff is Reach

I do not care about stack in terms of saddle-height - it is just 1.5cm diff. But in terms of handle-bar height, sometimes lower stack helps to lower the handlebar without slam it down too much.

And looks like the main diff is really only top-tube length, which is 61 or 64cm, and to compensate your saddle-handlebar distance all you need is stem which is 3cm longer or shorter. So, frame M+10cm stem = L+7cm stem or M+6cm = L+3cm. Looks simple - all I need is to decide stem length.

Small point that L frame adds 0.5cm _back_ to the saddle => to hold the same top-tube you should substract the 0.5cm from stem too.

If I go M => it is not very aggressive position compared to L, I can compensate it with stem, but, probably it is not idea on descend. and 3cm shorter wheelbase, which, probably makes it a bit more nimble, which is a plus for the long bike
If I go L => stem is shorter, and body position is a bit lower too, the only negative thing that stack increased, which prevents you from going lower with handlebar

[ilyamaksimov]

If I summarize all the basic math:

1) most of the droppers does not have offset => saddle moves forward even a bit more
2) The main diff for the frame makes seat-angle and Saddle-BB distance is ~8cm diff from old geometry => it is the ~same diff like Road and TT bike saddle

^^^ all the things are the ~same on M and L frames, so the only important diff is Reach

I do not care about stack in terms of saddle-height - it is just 1.5cm diff. But in terms of handle-bar height, sometimes lower stack helps to lower the handlebar without slam it down too much.

And looks like the main diff is really only top-tube length, which is 61 or 64cm, and to compensate your saddle-handlebar distance all you need is stem which is 3cm longer or shorter. So, frame M+10cm stem = L+7cm stem or M+6cm = L+3cm. Looks simple - all I need is to decide stem length.

Small point that L frame adds 0.5cm _back_ to the saddle => to hold the same top-tube you should substract the 0.5cm from stem too.

If I go M => it is not very aggressive position compared to L, I can compensate it with stem, but, probably it is not idea on descend. and 3cm shorter wheelbase, which, probably makes it a bit more nimble, which is a plus for the long bike
If I go L => stem is shorter, and body position is a bit lower too, the only negative thing that stack increased, which prevents you from going lower with handlebar

I have height 180, frame size L, stem 60mm

about the length of the stem. With a stem longer than 60mm, okay, 70mm oversteer becomes too strong, the bike tends to turn deeper into the turn and you have to steer the opposite way, not letting it go too far into the turn.

therefore, my advice for a height of 180 + cm is to take size L and stem of 50-70mm

[inv]

@ilyamaksimov, @carbonazza Thank you. I am going to L.

My calculations are here:

[inv]

Could someone recommend fork? Unfortunately I am far away from MTB to understand anything about it

RS/FOX. RS is cheaper, and I do not know if fox much better because it has 2x price
If RS, Do I need remote (for XC races)? I heard that Deluxe is fine for climbing without lock, but sidluxe is more DC shock that is why remote is necessary for uphill. Probably RT3 can solve it? What the f* is MegNeg? About SIDLuxe - not clear if trunnion has remote


My short list:

RockShox Deluxe RT3 Debon Air 165x42.5mm   268.9
RockShox SIDLuxe Ultimate RL Solo Air   285.71
RockShox Deluxe Ultimate RCT   286.9811939
Fox Suspension Float DPS Factory 3Pos-Adj SV   488.49
Fox Racing Shox Float DPS EVOL SV 3POS Factory Trunnion Rear Shock - 2022 Model   528.57
Fox Float DPS Kashima Factory Series 3Pos-Adj Trunnion Evol SV   569.5218394

Thank you,

[carbonazza]

There was a recent video of Dylan Johnson( Warning: I'm a fan ) about the need or not, to lock your suspension.


Few months ago, I decided to go without lock( every gram I could shed was good ), and don't regret it.
I remember to lock it manually once, because I knew the end of the race was a 2km road on asphalt and the other team was just behind us.

RS SIDLuxe is light and so far works great for me.
Not sure FOX shocks are twice as good 

[inv]

@carbonazza Thank you. will go into the direction too.


Can I continue with bunch of stupid questions?

1) do you know the link to the right bushings on bike24? I know it is 8x22.2. I found 2-3 of them on b24, but cannot understand if it is for sidluxe or not.
2) how many sets of them I need for trunnion? I found that standard shock needs 2x sets of bushing. Is it applicable for trunnion or just one is enough?
3) anything else I need to buy to setup the shock? Any mounts? Ah, probably shock-pump

Thank you,

[wfl3]

There was a recent video of Dylan Johnson( Warning: I'm a fan ) about the need or not, to lock your suspension.


Few months ago, I decided to go without lock( every gram I could shed was good ), and don't regret it.
I remember to lock it manually once, because I knew the end of the race was a 2km road on asphalt and the other team was just behind us.

RS SIDLuxe is light and so far works great for me.
Not sure FOX shocks are twice as good 

I came to the same conclusion as Dylan a long time ago.  "Feel" is subjective, but the clock never lies.  ;-)

[areid280]

Hi guys, I've finally assembled the bike and it looks great!

Unfortunately I'm facing a bit of an issue with the gear cable housing & routing

When I shift, instead of moving the RD, it tries to pull the gear housing flat from its curved shape / pulls it into the frame (either at the RD or entry at the head tube)

I've never had a bike where there isn't a form of stopper which prevents the outer housing getting pulled into the frame (see orange bike photo as a typical standard), and then the closeups of what I am using / used (ignore the sellotape that was just to test out the issue  )


I'm using a good quality Jagwire sport kit for what its worth




Can anyone please advise how they have sorted this? or if they have the same problem

I guess I could run a full length of gear cable from front to back?

Thanks

[SVChucko]

I think you will have to run the shifter cable housing the full length of the frame.