Obviously that could be the case, that my wheel is just one that has lower tension than it should have.j
Could be overly stiff causing frame to flex?
And my superstiff training wheels do not because… ???
If spoke tension is low, then wouldn’t deflection on one side of a stiff rim would result in greater deflection on the other side of the rim. In general, wouldn’t low spoke tension generally allow greater lateral deflection overall?
If spoke tension is low, then wouldn’t deflection on one side of a stiff rim would result in greater deflection on the other side of the rim. In general, wouldn’t low spoke tension generally allow greater lateral deflection overall?
I’m confused!
I’ll ask maybe a stupid question: skewer properly tightened down?
As a poster asked above also make sure the wheel is “squared” in the dropouts, meaning both sides of the axle seated in the same spot on each dropout.
Not uncommon for a qr axle to move in horizontal dropouts a little bit under heavy (standing) effort or hard braking. Espcially if the qr isn’t tight or seated evenly side to side.
Good luck!
Yes things are in properly and tighten down. However I will say the set screws in the dropouts I find a little confusing. With both of them set to the same distance from the drop out things do not sit in their Square. I need the non-drive side to be backed out a little more than the drive side for it to be square.
Maybe just variance in the mold and finished product.
I like the idea of testing with another wheel, it doesn’t cost anything so why not?
If spoke tension is low, then wouldn’t deflection on one side of a stiff rim would result in greater deflection on the other side of the rim. In general, wouldn’t low spoke tension generally allow greater lateral deflection overall?
No. Spoke tension merely keeps all of the wheel components in their particular locations (rim centered in dropouts and round) while ALSO allowing the tensioned components to actually bear compressive loads (since they can stay in tension if the preload is high enough). However, the STIFFNESS of the structure is NOT a function of the tension pre-load, but of the stiffnesses of the components. This is all “Pre-Loaded Structures 101” 
Now, theory is great and all…but luckily Damon Rinard went and measured this a long time ago and the data is still hosted on the old Sheldon Brown (RIP) website. Here’s the relevant plot:
To quote Damon,
Some believe that a wheel built with tighter spokes is stiffer. It is not. Wheel stiffness does not vary significantly with spoke tension unless a spoke becomes totally slack.
I measured the deflection of Wheel #2 while gradually loosening the spokes in quarter turn increments. The wheel did not display any significant change in stiffness until the spokes were so loose some became totally slack.
If the spokes are so loose that some become slack, the wheel becomes much more flexible. The last two data points below, 9 and 10, taken when the spokes were so loose the wheel was almost sloppy, show that the wheel becomes significantly more flexible when spokes on the detensioning side of the wheel actually become slack. That is expected: a slack spoke cannot add stiffness to the wheel; it buckles easily in compression.
I have exactly the same setup - NP3 and Flo 90 aluminium + carbon (the old version).
I’m 200 pounds and can put out quiet a bit of power - I have never experienced flex in the wheel or the frame, so I assume there is a problem with your bike somewhere
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I have exactly the same setup - NP3 and Flo 90 aluminium + carbon (the old version).
I’m 200 pounds and can put out quiet a bit of power - I have never experienced flex in the wheel or the frame, so I assume there is a problem with your bike somewhere
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At 200 do you have the Clyde’s build?
I have found that my horizontal drops on P2 cause wheel to rub. They aren’t completely level like you’re seeing, which means the wheel has some lateral “play”
Play with the screws a bit and I’m sure you’ll find a solution.
Yes, Clyde’s build Flos and size 61 NP3.
FWIW I got a set of Flo 45s for my road bike a couple months ago. My old aluminum Eastons flexed like noodles and would rub the brakes like you describe. But the Flos feel pretty stiff to me. I race crits on them, no brake rub and they feel great. I do have the clyde build specifically because I was fed up with flexy wheels. Actually, the availability of those 4 extra spokes was a major selling point for me.
One other thing to look at - I have not had to deal with this on the Flos but my old Eastons were notorious for the hub bearing tension loosening up and they required constant adjustment/retightening. If the hub adjustment was loose, you could flex the wheel just by grabbing onto the rim and pushing it side to side. If you have not done so already, check your hub.
Good stuff. So, the high-level summaries of the ST article I linked plus Damon Rinard’s studies are that wheel lateral stiffness is driven by:
of spokesThickness of spokesSpoke length (rim depth)Hub flange heightHub flange widthRim stiffness (aluminum not stiff, carbon clincher stiff)
So, is it reasonable to eliminate hub flange height and width for most wheels, except for a few specialty wheels that feature non-standard flange designs.
Also, is if reasonable to think of carbon rims with aluminum brake tracks similarly to regular aluminum rims?
Lastly, all perceptions about lateral wheel stiffness are probably wrong.
Also, is if reasonable to think of carbon rims with aluminum brake tracks similarly to regular aluminum rims?
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If they’re Flo’s, they aren’t carbon rims with aluminum brake tracks. They’re either aluminum rims with a carbon aero fairing, or they are carbon rims with carbon brake tracks. To my knowledge at least, Flo has never made carbon rims with aluminum brake tracks (someone will correct me if I’m wrong).
I’ve got Flo carbon rims with the clyde build. My weight fluctuates wildly between 215-245 lbs. I have broken the seat stay on a steel touring bike, cracked the chain stay on a carbon triathlon bike, and routinely destroy whatever rear wheel is standard equipment on any new bike I get. And I’ve never had the slightest hint of flex with my Flo wheels.
If they’re Flo’s, they aren’t carbon rims with aluminum brake tracks.
Maybe I should have been more specific… I know that Flos are aluminum rims with carbon fairings. Is this the way that most wheels are with aluminum brake tracks, or are there some wheels out there that are full carbon clinchers with an aluminum track bonded to the carbon?
If they’re Flo’s, they aren’t carbon rims with aluminum brake tracks.
Maybe I should have been more specific… I know that Flos are aluminum rims with carbon fairings. Is this the way that most wheels are with aluminum brake tracks, or are there some wheels out there that are full carbon clinchers with an aluminum track bonded to the carbon?
I had some Zipp 60s that were full carbon with bonded alloy brake tracks.
No, your wheel shouldn’t be moving in the dropout.
If it does your dropout is worn out, mishapen in production in damaged.
Compliance of a wheel is nothing to do with lateral flex.
A carbon deep rim rides nice because the tall carbon walls bow out to absorb bumps.
Carbon rims are generally stiffer laterally than alloy.
Put a whiteboard marker on your brake surface of your training wheels and sprint with the same brake clearances as the Flo.
Now tell me it wasn’t hitting as well.
It’s your frame.
So I think you are on to something we just need to identify more of the problem:
My question is what are you “squaring against”. If its rim/wheel not appearing square in the frame when the limit screws are equal then you need to determine if: 1) The wheel is out of true or 2: your dropouts are squiff.
Its most likely the wheel being out of true. You easily test this by putting the wheel in a bike with normal/ vertical dropouts and checking if everything is still square. If the wheel is still square check to see that your dropout are still securely bonded to the frame (no wiggling) along the metal carbon interface. This bond is an area of weakness in frames. I’m not totally familiar with the NP3 junction but have seen an issue in this area on a specialized transition. I have squashed the rear triangle in a crash on an alloy commuting bike which gave similar symptoms but carbon simply would bend in the say way the alloy bike did.
One other thing to look at - I have not had to deal with this on the Flos but my old Eastons were notorious for the hub bearing tension loosening up and they required constant adjustment/retightening. If the hub adjustment was loose, you could flex the wheel just by grabbing onto the rim and pushing it side to side. If you have not done so already, check your hub.
I had this happen to me on a shimano training rim. The wheel was true, but on the workstand, if you just pushed the wheel side to side there was play in the hub. Got the hub fully serviced and it has been fine since.
But I could easily tell it was the hub that was alloing the side to side play. At no time did I think it was the rim that was flexing.