Flip the brake release lever up and the rubbing will go away.

Still rubbing. Brake is so open it hardly stop's with brake lever fully compressed.

The wheel probably isn't fully seated in the dropouts.

Horizontal drop out. Fully seated

Have you inspected the frame for cracks?

No😐. Would it stick out on the paint job or are they tough to spot?

Here's a great article that explains stiffness: http://www.slowtwitch.com/..._Stiffness_3449.html

Maybe your spoke tension is low. Or, it could be a problem with the frame. You have a perfect storm with wide carbon wheels and the brake on the seat stay.

So now I'm thinking my p3 is flexing or it's in the HUD.

The paint would show it.

Inspected frame. No cracks. I'm bummed it could be flexing this much. Very annoyed.

Could the set screws in the drop outside be uneven. ? Even when they're adjusted to the same depth?

I'd get on a different bike and satisfy myself that doesn't rub in the same conditions. Then try the Flo in that bike and that back wheel in the NP3.

Wheels are stiff, frames are not.
Sometimes axles are flexy but that usually shows just by putting a heavy rider on the frame you will see the top of the wheel move towards the driveside at the seatstay.
Frames flex more laterally down at the BB under power so much more likely to get rubbing problems at a BB mounted brake.

Many frames rub brakes under sprint power, normally with alloy rims you simply don't hear it.
Because Carbon pads are generally very sticky and tend to make chirping or squealing noises when they touch you notice it and therefore conclude that it is the wheels at fault because you never heard it with your alloy rims.

So get a heavy guy to sit on your bike, if the wheel moves sideways at the top when he does, your wheel is the problem and you could do with looking for something with a better designed hubb with a larger diametre axle.
If it doesn't. it's your frame and more than likely this is what it will be.

Most times it will rub on the left downstroke before the right due to the chain trying to shorten things up on the right side.

I would put my money on the Flo wheels. I have an older P2 and with my training wheels (low alu rim, lots of spokes, made by wheelbuilder.com) I can put the brakes really close to the rim and I'll experience zero rub. Also, when I grab the wheel by the rim and try to pull it towards a brake pad there is absolutely zero movement of frame nor the wheel itself.

When I put a flo wheel in (the version with extra spokes) there is tons of flex and I always need really open my brake pads by a lot (so much I actually need to adjust the brake cable). Otherwise when I ride where will be serious rubbing whenever I stand up. When I grab the rim and pull it towards the brake pads the wheel moves/bends a lot (without the frame moving).

For that reason I'm not too excited about Flo wheels. Price is great and they've stayed true and have been free of any real issues, but the flex in the wheels is way too much. I've mentioned it here before and the Flo guys didn't really seem to believe me yet I'm sure it's the wheel that is flexing.

I don't believe you either. :)

Unless the spoke tension or hubs are seriously jacked up, I find it hard to believe it's the wheels.

Suggest an experiment or test I can do at home so I can compare both wheels. Or, as a minimum, explain to me why some wheels do not move / bend in my frame when the flo wheel does.

I'll also add that riding my training wheels is a much harsher ride - the wheels absorb a lot less vibration than the flo wheels do. Which again points to compliance. But happy to do an quantifiable test if you will suggest one.

I'm having a hard time thinking of a good test. I'm just going off my personal experience as a bike racer with 3 pairs of Flos. I like my brake pads set really tight to the rim. And as a road racer, I'm not the most powerful dude in the world, but I frequently get over 1100W or so. And I just never have an issue with brakes rubbing or any other sign of flex. Similar to Zipp and HED wheelsets I have (I'm a wheel whore).

I did admit it could be a manufacturing or assembly error. I just have a hard time believing it's a general characteristic of Flos.

Obviously that could be the case, that my wheel is just one that has lower tension than it should have.

Ummm...unless the tension is SO low that some of the spokes go completely slack, wheel lateral stiffness is NOT a function of spoke tension.

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http://bikeblather.blogspot.com/

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?

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?

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,

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http://bikeblather.blogspot.com/

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
.

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 spokes
• Thickness of spokes
• Spoke length (rim depth)
• Hub flange height
• Hub flange width
• Rim 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.

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.

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.

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.

Thanks for this post. I think I'm having a similar issue and will have to investigate when I get the chance. My rear wheel had some brake rub and turned out a bunch of spokes loosened up. When I fixed that I still noticed a lot of lateral play when pushing against the rim near the caliper. I will now look at my hub about what I can do to fix it. My setup is a HED C2 rim with DT240S hub. Was rock solid for years before it recently loosened up. I did take a jump off a curb and that is when it started.

I had the same problem with my p2 I just adjusted the screws until the wheel had the correct spacing either side.

The only frame we hear this complaint about is the P2... and now apparently the new P3. A few thoughts...

1. What tire are you running? Our rims are wider than standard training rims. Often times what happens is a customer will use the same tire on their FLO wheels as they do on their training wheels. The wider rim causes the same tire to sit much wider and what feels like the brake rubbing is actually the tire rubbing the frame. Are you certain the tire is not rubbing the frame?
2. Are you vertical drop out screws centered?

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Chris Thornham
Co-Founder And Previous Owner Of FLO Cycling

Conti 4000 ii 23s
Horizontal drop outs. Need to center them.

Can you confirm the tire is not rubbing?

Make sure you center them and see if that helps.

Let me know what you find out.

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Chris Thornham
Co-Founder And Previous Owner Of FLO Cycling

I will check in a bit and post on this thread. My Cervelo has several quarks that have me questioning my purchase,

:(

I had a FLO disc (an older version) that was flexy as fuck.Coupled with my B16 that's fairly flexy too it ready made me struggle on some climbs where I'd put out quite a bit of power.

Ended up selling it, as servicing it was damn near impossible.

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Next races on the schedule: none at the moment

I like the whiteboard marker idea. I actually measured on-road deflection of various wheels in this article for bike.com quite some time ago. Wheel deflection is a fun topic - not as straightforward as some might think (there is a section titled "stiffness/brake pad rub"):

http://biketechreview.com/...mance-bicycle-wheels

It's been a long time since I was in the wheel business, but it seems like the worst combo for pad rub (all else equal) would be high effective rim stiffness and low effective spoke stiffness which tends to cause the wheel to "tilt" under modest lateral loads. Poor rear hub design (inboard bearings that cantilever the freehub is a biggie) is also a contributing factor -> old-school cup and cone shimano freehub designs are well designed from this perspective.

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Kraig Willett
http://www.biketechreview.com - check out our reduced report pricing
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There have been a number of threads on this in the past. Almost all of them (Including me) ended up realizing their rear wheel was not being centered properly and the skewer not tight enough (Also check the set screws). I have P3 and have run a generic rear training wheel, Flo aluminum 60/90, Flo carbon 60/60 and the Flo aluminum disc over the years and if I don't center the rear wheel and tighten skewer well enough, they all will rub when under power like a sprint or standing while climbing.

Tons of stuff here and likely a combo from my experience with that frame and wheel. I would try different skewer (I used a Shimano) to see if you get better bite, non-drive side tends to "backout" under high load causing rub out top of flex. Move wheel in as far as possible within drops, slight material stiffening as you go in. This worked for me for 99% of the issue and never occurred racing just training with out of saddle hard efforts, the additional side to side with standing really exposes frame compliance.

Double check wheel dish and all the other things that others have said, but IMO it comes down to a frame that has spatial range to hold wider rims and tires but not the stiffness. HED plus also rubbed, C2's (23mm) did not.

Chris.

I had posted a while back about my flo aluminum 90 rubbing on my P3. The problem turned out to be a issue with my Dropout adjustment screws. Once that was cleared up the rubbing has been taken care of.

Thanks for following up. You'b be surprised how often this is the problem.

Take care,

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Chris Thornham
Co-Founder And Previous Owner Of FLO Cycling

flo 90 aluminium flexes on my p2, any remedy?

Let's start with some more details.

What have you already tried to remedy the issue?

Are you sure your drop screws are centered?

Where is the rub occurring? Carbon from wheel on carbon frame? Brake track on brake pad, or tire on frame? A tire that is too big often causes rubbing and people think it's their brake pads rubbing.

How do you know the wheel is what is flexing?

Have you tried the wheel on any other frame. The reason I'm asking is because the P2 is the only frame we see this issue with.

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Chris Thornham
Co-Founder And Previous Owner Of FLO Cycling