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Discussion Starter · #1 ·
Hi all fellow wheel builders and wheel enthusiasts!

So far, I have done two wheel builds:

Wheelset #1:

HED Belgium C2 Rims (not plus)
Shimano Ultegra 6800 Hubs
DT Swiss Competition Spokes
DT Swiss Brass Nipples
Laced: 32 spoke 3 cross front and rear

Wheelset #2:

DT Swiss R460 Rims
Shimano Dura-Ace 9000 Hubs
DT Swiss Aero Comp Spokes
DT Swiss Brass Nipples
Laced: 24 spoke 2 cross front / 32 spoke 3 cross rear

My recent observation is that Wheelset #1 appears to corner better and feel more stable than Wheelset #2 even though Wheelset #2 has slightly wider rims. I can't think of any reason for this other than the higher spoke count in the front on Wheelset #1.

Any thoughts?
 

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Same tires at the same stage of wear?

Slightly wider rims means you should use slightly lower PSI. The same PSI on different internal width rims doesn't equate to the same hard/soft feel.
 

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Discussion Starter · #4 ·
Same tires and same width. Wheelset #2 tires are newer (about 450 miles) than Wheelset #1 (about 2000 miles). On Wheetset #1, it did appear that the ride felt smoother as the tires wore, but the cornering feel didn't change.

Using the same PSI on both sets. HED C2s are 17mm internal, DT R460s are 18mm internal.
 

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Banned Sock Puppet
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Discussion Starter · #7 ·
OK, I'll give that a try, thanks!
 

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Discussion Starter · #9 ·
What's your weight? 32 spokes front and back seems overkill for wheel set #1.
I wanted to use Shimano Ultegra 6800 hubs which only come in 32 and 36 hole. 32 spokes on the front IS overkill. But so what? On wheelset #2, I decided to splurge and go for Dura-Ace hubs which have more drilling options, so I went with 24 in the front. I also have factory wheelsets that are 16 front / 20 rear. Guess what? None of these make me slower or faster than any of the others. Different feel as far as stability and cornering - yes. Speed or acceleration differences - NO.

I weigh 175lbs. in my birthday suit. On longer rides in sparsely populated areas, I carry a pack with extra water, food, tools, rain gear, etc. It all adds up. I also climb quite a few hills, so I like to have 32 rear to handle the extra torque. Maybe unnecessary? Can't hurt.

Overbuilding is much preferable to underbuilding.
 

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I wanted to use Shimano Ultegra 6800 hubs which only come in 32 and 36 hole. 32 spokes on the front IS overkill. But so what? On wheelset #2, I decided to splurge and go for Dura-Ace hubs which have more drilling options, so I went with 24 in the front. I also have factory wheelsets that are 16 front / 20 rear. Guess what? None of these make me slower or faster than any of the others. Different feel as far as stability and cornering - yes. Speed or acceleration differences - NO.

I weigh 175lbs. in my birthday suit. On longer rides in sparsely populated areas, I carry a pack with extra water, food, tools, rain gear, etc. It all adds up. I also climb quite a few hills, so I like to have 32 rear to handle the extra torque. Maybe unnecessary? Can't hurt.

Overbuilding is much preferable to underbuilding.
All of this. Also, a broken spoke won't end a ride.
 

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Discussion Starter · #11 ·

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These two rims are comparable and the extra 1 mm I don't think would make much difference. I agree with you that the number and type of spokes seems to be the variable causing what you experience and it maybe because the HED rim is better supported.
 

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You have more spokes on the stiffer rim. The width difference is more or less inconsequential (isn't C2 18mm internal anyhow?), and without doing a full calculation I think using 5 psi less is overkill. The variation in tires from one to the other could overcome that rim width difference.

Same tubes as well as tires?

Same skewers?

For what it's worth, I'm a particularly aggressive bike handler cornering-wise (I have lots of downhill KOMs) and there's nothing I can do that a well-built 20h front with good components can't support. I weigh 160. There is no reason on earth that there should be cornering deficiencies with the 24h wheel.
 

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Discussion Starter · #14 ·
These two rims are comparable and the extra 1 mm I don't think would make much difference. I agree with you that the number [of spokes]
You have more spokes on the stiffer rim. The width difference is more or less inconsequential........
This is what I suspected.

...........and type of spokes seems to be the variable causing what you experience and it maybe because the HED rim is better supported.
I hadn't thought that there may actually be a difference in feel between DT Competitions and DT Aero Comps, or that the HED C2 rims may be stiffer than the DT R460s.

(isn't C2 18mm internal anyhow?)
No. The C2 is 17mm.

Same tubes as well as tires?
All standard Kenda butyl tubes.

Same skewers?
Skewers that came with the hubs.

For what it's worth, I'm a particularly aggressive bike handler cornering-wise (I have lots of downhill KOMs) and there's nothing I can do that a well-built 20h front with good components can't support. I weigh 160. There is no reason on earth that there should be cornering deficiencies with the 24h wheel.
You're definitely way more aggressive on the downhills and corners than I am. Therefore I am assuming that you are probably less sensitive to variations in cornering feel and stability. Don't know what else to think.
 

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The C2s I just measured are 17.85.

As for cornering, my assumption would be that more aggressive cornering would unquestionably highlight differences between wheels. The more demand you place on the equipment, the more the differences show. I can't see any way how that would possibly be different.
 

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The C2s I just measured are 17.85.

As for cornering, my assumption would be that more aggressive cornering would unquestionably highlight differences between wheels. The more demand you place on the equipment, the more the differences show. I can't see any way how that would possibly be different.
I think he was trying to be polite to himself and was really saying his skill isn't very good compared to yours so he's prone to be thrown by slight variations that you'd probably deal with subconsciously and not realize you did.

Aggressive is one thing, level of aggressiveness relative to skill level is quit another.

Not that that necessarily makes sense either but it's the only way I can think how that would possible be different.
 

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Discussion Starter · #17 ·
I think he was trying to be polite to himself and was really saying his skill isn't very good compared to yours so he's prone to be thrown by slight variations that you'd probably deal with subconsciously and not realize you did.

Aggressive is one thing, level of aggressiveness relative to skill level is quit another.
LOL. I think you hit the nail on the head, Jay. While I'm generally a pretty good hill climber, bombing down hills with twists and turns is not my forte.
 

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I hadn't thought that there may actually be a difference in feel between DT Competitions and DT Aero Comps, or that the HED C2 rims may be stiffer than the DT R460s.
Yes, the Aero are bladed spokes, thus more flexible. That's the reason why they are often replaced with stiffer double butted spokes on the drive side as the first step when the circumstances call for a stiffer wheel.

Whether the HED C2 is stiffer than the R460 I'm not sure. IMO, these two rims are pretty similar so any difference in rim stiffness would be insignificant.
 

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Yes, the Aero are bladed spokes, thus more flexible. That's the reason why they are often replaced with stiffer double butted spokes on the drive side as the first step when the circumstances call for a stiffer wheel.

Whether the HED C2 is stiffer than the R460 I'm not sure. IMO, these two rims are pretty similar so any difference in rim stiffness would be insignificant.
Are you sure about this? DT Competitions and DT Aero Comps are precisely the same weight, per DT's page. Their stiffness in a wheel would be dependent on cross sectional area and Young's Modulus of the material. Since they're the same material, Young's Modulus is the same. Since they're the same material and the same weight, cross sectional area must be the same. Ergo, same stiffness. Having been cold worked into the bladed shape, the Aero Comps probably have a significantly higher tensile strength, but that's not relevant here.

On the other hand, I have directly measured a stiffness difference between R460 and C2 in favor of the C2. The alloys used are clearly not the same, which is observable when you handle and build them.

Neither set of wheels is anything resembling underbuilt for the OP's purpose.
 

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Are you sure about this? DT Competitions and DT Aero Comps are precisely the same weight, per DT's page. Their stiffness in a wheel would be dependent on cross sectional area and Young's Modulus of the material. Since they're the same material, Young's Modulus is the same. Since they're the same material and the same weight, cross sectional area must be the same. Ergo, same stiffness. Having been cold worked into the bladed shape, the Aero Comps probably have a significantly higher tensile strength, but that's not relevant here.

On the other hand, I have directly measured a stiffness difference between R460 and C2 in favor of the C2. The alloys used are clearly not the same, which is observable when you handle and build them.

Neither set of wheels is anything resembling underbuilt for the OP's purpose.
Your description on wheel stiffness as it pertains to spoke stiffness would be accurate for axially applied loads at a static wheel. However, this is not the case while the wheel curves around a turn. There you have radial, lateral and torsional loads that in turn challenge the radial, lateral and torsional stiffness of the wheel as a whole.
Furthermore, I believe the shape of the spokes influences all of the above since the shape of an object affects its flexular rigidity (a.k.a bending stiffness) in relation to the direction of the applied load. Easier to bend sheet metal along its wide axis than a metal rod of same length and overall weight. This is also the same principle that the increased fatigue life of the bladed spokes vs. round spokes is based on.

In reference to your statement about the rigidity between these two rims: My understanding is that shape and weight affect the rim stiffness significantly more than the variations between the aluminum alloys used for rim construction. However, I will accept your conclusion simply because I believe that one actual measurement is better than fifty theoretical deductions. I would be very interested to see your measurements on these if you care to share.
 
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