FM1002 / FM1166 - 150mm frame

[Julian]

Good point. I’m aware of the relation between spring and leverage curves, I was just trying to keep my question relatively short — and coming from a GT Force (avg leverage 2.79 and only moderately progressive), I was thinking of the fact that even the max 700lb coil felt too soft for me on that bike with the limited support the Bomber CR damper gives.

Looking at the kinematics graphs for these bikes, I thought maybe it was progressive enough given the low average, at least for a progressive coil rather than a regular linear one. But the context you gave made me look again and I definitely take your point. The dip near the end of travel in particular isn’t great for coils.

The average leverage also had me thinking of damping, as the main 185x55 air shock I have to spare is a DPX2 with standard Medium tune. That was overdamped for my Force (different models/years have shipped with both Low and Medium tunes), so I was thinking less leverage meant it would be even more overdamped for a 1001. But of course you reminded me that it’s not that straightforward, the curve matters here too.

I might just get a 1002 and a DVO Topaz for it — the same stock damping tune that helped my Force because it’s lighter than Fox or RS’ Mediums, and it’s very tunable for different spring curves — but I wanted to think through all the possibilities before I gave up on using one of my existing 185x55 shocks with a 1001.

Ah, now I get your point. You're absolutely right, lower average lev ratio means you won't have the issue of not finding a spring that's hard enough.

Sadly, I think even a progressive coil spring won't help with a progression of less than 10% from SAG point... But maybe someone will start making custom upper links, that would be awesome 

Not sure about the damping thing, but yeah, if it's already overdamped with more travel, then a lower average lev ratio and less travel will probably make it even worse.

[ESC]

Wing sent through some photos of the paint job. Colour is RAL4011

[ESC]

Did they give you a whole range of metallic paint color options? I haven’t seen any info posted here about that.

I just asked for a quote on their metallic RAL paint options. From what I can gather there’s 15 colours in total.

Got the track number today. I’d be impressed if I received it before xmas. 

[Massey]

Looking to buy my first Chinese frame and 99% sure I'm going to buy FM1002 in XL, I was wondering if anyone knew what the biggest dropper you could fit? would love to get 200mm drop but would still be happy with 180/175mm. Any help would be appreciated!

[Julian]

Looking to buy my first Chinese frame and 99% sure I'm going to buy FM1002 in XL, I was wondering if anyone knew what the biggest dropper you could fit? would love to get 200mm drop but would still be happy with 180/175mm. Any help would be appreciated!

You could fit any dropper post, so long as your legs are long enough

The XL has a 470mm seat tube and a 220 max insertion as far as I know. All dropper posts with that much travel have longer max insertions, so they won't go in all the way. You'll have to take that into account.

If you tell me your saddle height (BB to middle of saddle clamp), I can do the math for you.

[Massey]

You could fit any dropper post, so long as your legs are long enough

The XL has a 470mm seat tube and a 220 max insertion as far as I know. All dropper posts with that much travel have longer max insertions, so they won't go in all the way. You'll have to take that into account.

If you tell me your saddle height (BB to middle of saddle clamp), I can do the math for you.

Do have long legs not sure they are that long thought! haha.

From the middle of the bb to the seat clamp is 79cm on my current bike

[Julian]

Do have long legs not sure they are that long thought! haha.

From the middle of the bb to the seat clamp is 79cm on my current bike

That should even work with a OneUp V2 210mm.

If my diagram is correct, you'll have about 330mm of space between saddle clamp and seat clamp. The 210mm OneUp V2 will stick out about 60mm and has a stack height of 33mm, so 320 - 60 - 33 = 227mm possible dropper travel. The OneUp is pretty compact though, so a different brand might give you a lot less.

[Massey]

That should even work with a OneUp V2 210mm.

If my diagram is correct, you'll have about 330mm of space between saddle clamp and seat clamp. The 210mm OneUp V2 will stick out about 60mm and has a stack height of 33mm, so 320 - 60 - 33 = 227mm possible dropper travel. The OneUp is pretty compact though, so a different brand might give you a lot less.

Thanks for the help! I am looking at the PMW loam dropper that has a full insertion length of 290mm and 200mm of drop and I'm pretty sure it would just about be the right. I did the dropper size calculator on there website and it says 200mm drop will work but will hold out till I have the frame just to double check, the weather is Scotland is pretty bad for a few more months so in no rush to build up the frame and want everything to be spot on! Will be ordering the frame on Monday and very excited to get it.

Will keep everyone on here updated on the build 

[FlaMtnBkr]

On the lower trunnion shock mount, are there bearings or bushings there? The bolts look similar to other pivot points that contain bearings so I'm curious. The shock shouldn't move much in relation to the frame at the bottom mount, but will move some so I'm hoping they have done something to accommodate the movement.

I want to buy this frame as I'm in need of one, but I'm a bit skittish as the owner of an unrideable AM831...

[deucelee]

On the lower trunnion shock mount, are there bearings or bushings there? The bolts look similar to other pivot points that contain bearings so I'm curious. The shock shouldn't move much in relation to the frame at the bottom mount, but will move some so I'm hoping they have done something to accommodate the movement.

I want to buy this frame as I'm in need of one, but I'm a bit skittish as the owner of an unrideable AM831...

I haven't built up my AM831 frame yet as I just got it last week but yes, I'm not too happy about the flexing issues ATM. 

[smoothmoose]

Linkage Check - Carbon frame from Flybike l Modern geometry and good kinematics? l FM1166


https://insanityofgravity.blogspot.com/2020/11/6-linkage-check-carbon-rahmen-von.html

Thanks for the kinematics analysis!  This is a very cool frame.  Geometry would work with 29 or mullet (29/27.5).  For mullet I would put a 170mm fork to raise the BB.  This will ride similar to the Specialized Stumpjumper EVO and based on the leverage curve (slight progressive then regressive), should run an air shock, unless you are not an aggressive rider at all and light.

It's almost there, but not quite for me, as I'm looking for something with more leverage, and flatter anti-squat.  But cool to see a modern geometry that works as MX.

[smoothmoose]

I want to buy this frame as I'm in need of one, but I'm a bit skittish as the owner of an unrideable AM831...

What's the issue with the AM831 - isn't that one just a copy of the Santa Cruz Hightower?

[endo.alley]

That 830 looks interesting too.

[FullCarbonAlchemist]

That 830 looks interesting too.

It does, on paper, but as some of the folks affected by the 831 situation have pointed out, there’s an extra risk in trusting a company that would bring such a flawed product to market without adequate field testing, and then charge $200+shipping for a “fix” that itself still appears to be fatally flawed.

The 830 *looks* like it wouldn’t suffer from the same problems, but with no field testing, we can’t be sure…and a dual-link swingarm bike puts lots of strain on the links’ bearings so it wouldn’t take much of a design flaw to cause issues with flex, bearing damage etc.

Don’t get me wrong, I’m extremely tempted by the 830 myself and would rather have one than a relatively generic 4-bar with an upside down shock. But I’m doing an unbranded frame build because I’m on a tight budget — not because I have the leeway to try all over again with a second frame because the first was a lemon.

[endo.alley]

Yeah agreed. There just is not enough good feedback on the completed bikes for many of these frames. If the chainstays and seatstays on these bikes are under engineered and flexy, going to a Horst link configuration connected to a vertical pivot link isn't necessarily going to fix it.