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Discussion Starter · #1 ·
Anyone seen the latest issue of Velonews? They do a relatively scientific quantitative test of 6 different super deep wheels (Hed, Zipp, Cole, Vision, Bonti, Easton. Sorry, no custom Edge/Sapim/240) and then give them to test riders for their input.

2 things I found interesting:

The Hed Stinger 9s had significantly lower drag than the other wheels, possibly validating Hed's obsession with rim shape.

The Eastons were less stiff than the other wheels in the test (with their 12 spokes and narrow flanges) but the test riders didn't notice. Do we obsess over wheel stiffness too much?
 

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I'll have to pick up an issue and give it a read.

Regarding wheels stiffness, I don't want my wheels to rub my brakes. I've never had that problem with any of the 5 wheelsets I've ridden, but I've heard this is the most noticeable attribute of non-stiff wheels. I wonder why they didn't include Edge or a set of Carbones?
 

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bwhite_4 said:
I'll have to pick up an issue and give it a read.

Regarding wheels stiffness, I don't want my wheels to rub my brakes. I've never had that problem with any of the 5 wheelsets I've ridden, but I've heard this is the most noticeable attribute of non-stiff wheels. I wonder why they didn't include Edge or a set of Carbones?
I don't understand how wheels could possibly rub the brakes. There's no force on them up by the brakes and in order for them to move up there wouldn't the skewers need move within the or drop out (which isn't going to happen)?

Sorry for the diversion. I'm just trying to figure out if wheels rubbing on the brakes due to lack of stiffness is an urban legend or if I'm just being stupid as usual.

How is it physically possible for that to happen?
 

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Discussion Starter · #4 ·
bwhite_4 said:
I'll have to pick up an issue and give it a read.

Regarding wheels stiffness, I don't want my wheels to rub my brakes. I've never had that problem with any of the 5 wheelsets I've ridden, but I've heard this is the most noticeable attribute of non-stiff wheels. I wonder why they didn't include Edge or a set of Carbones?
Neither makes 80+mm deep wheels, which is what they were testing.
 

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Hank Stamper said:
I don't understand how wheels could possibly rub the brakes. There's no force on them up by the brakes and in order for them to move up there wouldn't the skewers need move within the or drop out (which isn't going to happen)?

Sorry for the diversion. I'm just trying to figure out if wheels rubbing on the brakes due to lack of stiffness is an urban legend or if I'm just being stupid as usual.

How is it physically possible for that to happen?
I don't have analytical data to support this claim. When I first got into cycling my bike came with mavic ksyrium wheels (don't remember exactly the model) but they could be had for around $300/set at REI. Anyways when I accelerate hard on a hill climb, the front braking surfaces always rub against the brake pads side to side. It was the most annoying thing. I upgrade to a better set of wheels later on and didn't encounter this problem again, so don't think it's the fork that was flexing.
 

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Discussion Starter · #7 ·

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kbiker3111 said:
Obviously the way they decided to rank the wheels overall is poor. I'm not sure how that invalidates the results of the individual tests or the way in which they presented the individual results or even the end results of the overall ranking (Zipp 808's are really nice wheels).
The fact that they gave equal weight to aerodynamics, with a 9W spread, and rotational inertia, with at most a 0.045W spread, indicates to me that they either don't understand what properties of a wheel affect performance or they want to appear more knowledgeable than others by considering properties in addition to aerodynamics. In either case, they lose credibility because they are not designing tests to scientifically separate the performance differences between the wheels correctly.
 

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Yeah, but as someone else mentioned, they split everything out. So you can judge just on one thing if you want. In the case of Aerodynamics, the HED's were fastest.

Interestingly enough, the HEDS also have the most spokes out of all the test wheels.
 

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Hank Stamper said:
I don't understand how wheels could possibly rub the brakes. There's no force on them up by the brakes and in order for them to move up there wouldn't the skewers need move within the or drop out (which isn't going to happen)?

Sorry for the diversion. I'm just trying to figure out if wheels rubbing on the brakes due to lack of stiffness is an urban legend or if I'm just being stupid as usual.

How is it physically possible for that to happen?

as you pull on the bars and your bike is at an angle other than 90 deg to the road, you will have a "side" load on the rim. as the bottom deflects one way, the top will deflect the other, causing them to potentially rub on the brakes. i have had it happen with a set on hill repeats. i had to move the pads out more so they wouldn't rub.
 

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nightfend said:
Yeah, but as someone else mentioned, they split everything out. So you can judge just on one thing if you want. In the case of Aerodynamics, the HED's were fastest.
Yes, you can if you already know enough about the relative magnitudes of the areas tested, but the article never presents that information and gives the misleading impression that all are to be considered equally. The fact that a knowledgeable reader can correct the errors in the study does not mean the study does not have the errors.
 

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Hank Stamper said:
I don't understand how wheels could possibly rub the brakes. There's no force on them up by the brakes and in order for them to move up there wouldn't the skewers need move within the or drop out (which isn't going to happen)?

Sorry for the diversion. I'm just trying to figure out if wheels rubbing on the brakes due to lack of stiffness is an urban legend or if I'm just being stupid as usual.

How is it physically possible for that to happen?
Stiffer rims with fewer and or lighter spokes will be more likely to rub the brakes since the rim is better able to transmit the lateral force applied where the wheel contacts the ground to the opposite side of the wheel, which is near the ,brakes. Wheels with light weight alloy rims and high spoke counts will isolate the lateral deflection around where the load is being applied. These wheels could have twice the lateral deflection per unit of force of a wheel with a stiff rim and low spoke count but most people will think the later is the less stiff of the two since it is rubbing the brakes.
 

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mpk1996 said:
as you pull on the bars and your bike is at an angle other than 90 deg to the road, you will have a "side" load on the rim. as the bottom deflects one way, the top will deflect the other, causing them to potentially rub on the brakes. i have had it happen with a set on hill repeats. i had to move the pads out more so they wouldn't rub.
Thanks for the answers, guys. I'm still not totally grasping how as the bottom deflects one way the top can deflect the other if they are anchored in the middle but I'm not always the sharpest knife on the tree.
I'm picturing this as if I was to hold a pie plate (wheel) in the middle with my fingers (fork or drop out) there's just no way (that I can grasp) to move the top by applying pressure to the bottom without my fingers moving.
 

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You've never sprinted hard on a rear wheel and felt the back tire rub against the brakes? I've had this happen on lightweight wheels. Sometimes, if you really put the watts down, you can flex the tire enough to rub the chainstays.
 

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Hank:
grab your bike, throw her upside down, and pull sideways on the highest point of one of the wheels.
watch as the lowest part (which would normally be the top) moves the opposite direction.
 

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You've never sprinted hard on a rear wheel and felt the back tire rub against the brakes? I've had this happen on lightweight wheels. Sometimes, if you really put the watts down, you can flex the tire enough to rub the chainstays.
Lew Racing PRO VT-1 lateral stiffness - YouTube

The above link has a gruesome clip of a guy pulling the wheel all the way over and then seeing the spoke contort where he is able to move it back and forth at will. I am just left to wonder by him doing this, did it cause perm damage to the wheel? My guess would be not as long as it did not go past the yield point but if what you say is true Nightfend, that you are able to get the tire to touch the chainstay then I would have to conclude no damage at all.
 
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