Carbonda fm936 Thoughts

[acedeuce802]

I probably wouldn't.  If 120mm was achieved by just taking out the shock spacer, then I'd be all for it.  But since the 120mm linkage raises the rear, you'd end up with a ~78deg seat tube, and ~68deg head tube.  Maybe it won't feel too weird, and I'm sure it'd be fine if you had plans to moving to a 120mm fork in the future.  But if you are set on using the Sid SL, then just get the normal linkage.

[volan]

I probably wouldn't.  If 120mm was achieved by just taking out the shock spacer, then I'd be all for it.  But since the 120mm linkage raises the rear, you'd end up with a ~78deg seat tube, and ~68deg head tube.  Maybe it won't feel too weird, and I'm sure it'd be fine if you had plans to moving to a 120mm fork in the future.  But if you are set on using the Sid SL, then just get the normal linkage.

Are you sure about cca 1° change in ha/sa with 120mm rear link? I read somewhere here on the thread that new link should raise the rear 3-5mm, and since when we raise the fork for 20mm, the hta changes for a degree, then 3-5mm raise shouldn't translate into 1° difference... i think. pls correct me if my math is off.

[jannmayer]

Edit: My original post was wrong, so I'm deleting it to avoid misleading anyone.

[acedeuce802]

If the clearance between seat stay bridge and seat tube are the same at bottom out, when comparing normal linkage with 165x40 to new linkage with 165x45, then the amount the rear wheel gets pushed down is the difference in travel.  I guess we don't really know what that is.  Let's say the original setup is 105mm (not sure if the actual travel has been settled) and new linkage setup is 120mm.  Then the rear wheel will get pushed down 15mm.  This will not be true if the position of the rear triangle sinks further into the travel on the new linkage setup (as if the clearance between seat stay bridge and seat tube was more similar to original linkage and 165x42.5mm shock), or if the travel achieved isn't actually 120mm.  Since the rear triangle isn't changing, there's no way the rear wheel is only pushing 3mm downward, that would mean 3mm of travel gain, assuming similar bottom out clearance.

Bottom bracket location makes no difference to how the angles change.  What if you put the BB in the middle of the fork axle, like a kids tricycle?  If you extended the rear wheel downward, the bike would still change by the same angle.  When extending the fork, the bike pivots around the rear axle.  When changing the linkage and pushing the rear wheel down, the bike pivots around the front axle.  Vertical wheel location change and wheelbase are all the matter.  BB location only matters for BB height change.  If we trust Carbonda's geo charts, then what I said is true.  40mm/old-linkage = 67/77deg.  Use a geo calculator for 120mm fork with 40mm/old-linkage = 66/76deg (1 deg change to 120mm fork).  45mm/new-linkage and 120mm fork (from Carbonda chart) = 67/77deg.  This if we trust their chart, original linkage to new linkage is a 1deg frame angle change.  Thus you can interpret that new linkage with 100m fork would be 1deg the other way, 68/78.

[jannmayer]

Bottom bracket location makes no difference to how the angles change.  What if you put the BB in the middle of the fork axle, like a kids tricycle?  If you extended the rear wheel downward, the bike would still change by the same angle.  When extending the fork, the bike pivots around the rear axle.  When changing the linkage and pushing the rear wheel down, the bike pivots around the front axle.  Vertical wheel location change and wheelbase are all the matter.  BB location only matters for BB height change.  If we trust Carbonda's geo charts, then what I said is true.  40mm/old-linkage = 67/77deg.  Use a geo calculator for 120mm fork with 40mm/old-linkage = 66/76deg (1 deg change to 120mm fork).  45mm/new-linkage and 120mm fork (from Carbonda chart) = 67/77deg.  This if we trust their chart, original linkage to new linkage is a 1deg frame angle change.  Thus you can interpret that new linkage with 100m fork would be 1deg the other way, 68/78.

You're absolutely right - I was wrong to look at the distances to the BB. There will be a slight difference due to the increased wheelbase of the larger sizes, but that isn't very significant.

[volan]

I think I've decieded. I'm gonna go for the 120mm rear linkage, and 120mm fork. I want this bike to be my gnarlier race-oriented dc machine... BUUUT... Only quibble I have is the remote lockout. I really want to have the possibility of locking out the shock. Since I do plan to race on in, and my local races have lots of fireroad climbs... So I really need that lockout. I went through all 150 pages, and learned:

1. sidluxe doesnt have 165x45 with remote? possible with 150ish€ top cap that seems nowhere in stock 
2. fox dps doable? pricey in eu 
3. manitou mara cable exits downwards and makes it hard
4. dt shock r232? also pricey

So what options do I have for 45mm travel shock and rem. lockout? Please say there is something doable 

[acedeuce802]

FYI the Mara doesn't even fit going downward. I've had it in another frame with similar layout and it was a tight bend, but worked. But there's not enough clearance on the FM936. I 3D printed a little clamp for the air can that makes it a side exit, got a picture on page 148 and can print more.

[Arno Knell]

https://www.bike-components.de/de/DT-Swiss/R-232-ONE-Trunnion-Remote-ready-Daempfer-p76022/
@volan,
this could be the right one for you

[urbs]

If the clearance between seat stay bridge and seat tube are the same at bottom out, when comparing normal linkage with 165x40 to new linkage with 165x45, then the amount the rear wheel gets pushed down is the difference in travel.  I guess we don't really know what that is.  Let's say the original setup is 105mm (not sure if the actual travel has been settled) and new linkage setup is 120mm.  Then the rear wheel will get pushed down 15mm.  This will not be true if the position of the rear triangle sinks further into the travel on the new linkage setup (as if the clearance between seat stay bridge and seat tube was more similar to original linkage and 165x42.5mm shock), or if the travel achieved isn't actually 120mm.  Since the rear triangle isn't changing, there's no way the rear wheel is only pushing 3mm downward, that would mean 3mm of travel gain, assuming similar bottom out clearance.

Bottom bracket location makes no difference to how the angles change.  What if you put the BB in the middle of the fork axle, like a kids tricycle?  If you extended the rear wheel downward, the bike would still change by the same angle.  When extending the fork, the bike pivots around the rear axle.  When changing the linkage and pushing the rear wheel down, the bike pivots around the front axle.  Vertical wheel location change and wheelbase are all the matter.  BB location only matters for BB height change.  If we trust Carbonda's geo charts, then what I said is true.  40mm/old-linkage = 67/77deg.  Use a geo calculator for 120mm fork with 40mm/old-linkage = 66/76deg (1 deg change to 120mm fork).  45mm/new-linkage and 120mm fork (from Carbonda chart) = 67/77deg.  This if we trust their chart, original linkage to new linkage is a 1deg frame angle change.  Thus you can interpret that new linkage with 100m fork would be 1deg the other way, 68/78.

This is very helpful and, as far as I understand it, correct. BB height change is not causing the angle changes. But it is worth noting that raising the front (longer fork) and pressing down the rear (with the 120 linkage) BOTH raise the BB. Hence the 10mm higher BB height in the Carbonda diagram, which is likely an underestimate in how much the BB drop changes given that they do the calculation with a 520 fork.

I've installed the new linkage and cut out my shock spacer (to make it 45mm), hence I now have it setup in the new 120/120 mode. I notice the slightly steeper HA compared to the 100/120 I was running before, but I also notice the higher BB (it feels like I'm riding more on the bike that in it). So,  I'm wondering if there would be clearance to use one offset bushing and reverse a small part of the work of the linkage change. Maybe carbonda went too far in pushing the rear end down. If it is possible to run the 45mm shock but with a little less extending out the rear end that might be ideal. So, I'm toying with the idea of ordering a 2mm offset bushing and seeing what happens. I'll report back if I do that (although it might take a while).

[acedeuce802]

Does anyone know the actual seat stay bridge to seat tube clearance when a 165x42.5mm is bottomed out?  I can measure on mine at some point.  If we knew that, then you can remove the linkage/shock bolt and compress the rear triangle until that clearance is achieved (say 42.5mm clearance is 5mm, just take a 5mm allen key or something and stick it inbetween the bridge and seat tube and bottom it out).  Then measure eye to eye and see if it's more or less than what the 165x45mm is at bottom out.

[HAL_69000]

Hi folks, first time poster here. About to order one of these and want to have a friend paint it. I'm trying to get a finish that will be amenable to painting. Has anyone done this? Wing suggested standard matte, but I notice in the form letter that Carbonda sends out that this comes with a clearcoat. I don't think that this would be ideal for painting? However Wing warns that a completely bare frame would not be smooth and would have to be "polished". I think he means sanded?

Any tips or ideas from folks that have had theirs painted after receiving it?

[Tijoe]

Seems like a conundrum to me.  Have you asked if you can purchase a primered frame?
If not;
Ask if they are powder coating their frames. 
Then find out if they use a water base paint, or solvent based paint. (Can make a difference in what paint you use and your preparation.)
If the frame is clear coated over their color paint, then at a minimum, the clear coat will have to be sanded, and perhaps sealed, before you paint the top coat you want.
If you receive a bare frame, then you will likely have to fill and sand any defects on the frame, before the primer, color layer, and perhaps clear coat.
(The other thing I don't like is that if you paint over their paint, you are adding more weight to the frame.  Not much, but it adds up.)

On a side note, Automotive/high quality paints have become so expensive here in the states, ($50+/qt) that I would consider paying the price that the frame seller charges to custom paint your frame.  May be worth it in the long run.

[HAL_69000]

Seems like a conundrum to me.  Have you asked if you can purchase a primered frame?
If not;
Ask if they are powder coating their frames. 
Then find out if they use a water base paint, or solvent based paint. (Can make a difference in what paint you use and your preparation.)
If the frame is clear coated over their color paint, then at a minimum, the clear coat will have to be sanded, and perhaps sealed, before you paint the top coat you want.
If you receive a bare frame, then you will likely have to fill and sand any defects on the frame, before the primer, color layer, and perhaps clear coat.
(The other thing I don't like is that if you paint over their paint, you are adding more weight to the frame.  Not much, but it adds up.)

On a side note, Automotive/high quality paints have become so expensive here in the states, ($50+/qt) that I would consider paying the price that the frame seller charges to custom paint your frame.  May be worth it in the long run.

You're right in that it would make the most sense to have Carbonda do it from a paint quality perspective. However the person I am asking to do it is a pretty accomplished artist that has also started making his own steel frames (and painting them) so while the paint job won't be as durable, I know he will do something cool and interesting and that ultimately matters more to me than the quality of the products being used. And yes, it will also cost more.

This is what Wing sent me initially for paint options:

standard matte : free
standard matte is between black matte and UD matte , It have clear coat protect the paint
 
UD matte , UD glossy : $105
One color: US:$70.00(matte or glossy,solid color )
Two colors: US$ :95.00 ( all matte or all glossy,solid color )
Two colors: US$ :105.00 ( matte and glossy,solid color )
Two color gradient : US$ :115.00 ( all matte or all glossy ,solid color )

I asked him for more information about what standard matte is. I'm hoping that someone here might be able to shine more light on this too. My friend meanwhile said that standard matte should work since he will have to do sanding prep-work regardless.

[jannmayer]

I asked him for more information about what standard matte is. I'm hoping that someone here might be able to shine more light on this too. My friend meanwhile said that standard matte should work since he will have to do sanding prep-work regardless.

I painted a Carbonda frame that had the standard matte finish. I sanded it down a bit first (not all the way to the carbon) before spraying with a 2k primer. The primer has held without any issues. All of my paint chips have only taken the color layer off and left the primer, so I think it's fine to paint over their matte finish.


I wrote up my experience on another thread:
https://chinertown.com/index.php/topic,3714.0.html

[carbonazza]

This is what Wing sent me initially for paint options:
Quote
...
UD matte , UD glossy : $105

Do you know what is this option?