Wheels

bobbyOCR said:

BTW. Ksyriums suck.

Very poor aerodynamics. Not really even that light. But look nice. Great marketing department.

I think alienator hit on the head, in that I would like to see some actually figures for things like power loss through flex however this could be very subjective based on the size of the rider, how they throw the bike around out of the saddle etc. Damned if I know how you could test it. Curiousity more than anything! rouesartisanales.comarticle 4934445.htmlOpen ↗ from this link they give stiffness values in N/mm2. Could someone explain what that actually means?

FWIW, I use Velocity Razors for training and Campy Neutrons for racing. Both seem pretty stiff and handle well. Probably not the most aero though.

I thought the Kysriums were great... for keeping you cool with all the air they push around :p

Tapeworm said:

rouesartisanales.comarticle 4934445.htmlOpen ↗

I think that every one of the ratios mentioned in the article is arbitrary and meaningless. But I found the drag figures very interesting.

Tapeworm said:

I think alienator hit on the head, in that I would like to see some actually figures for things like power loss through flex however this could be very subjective based on the size of the rider, how they throw the bike around out of the saddle etc. Damned if I know how you could test it. Curiousity more than anything! rouesartisanales.comarticle 4934445.htmlOpen ↗ from this link they give stiffness values in N/mm2. Could someone explain what that actually means?

FWIW, I use Velocity Razors for training and Campy Neutrons for racing. Both seem pretty stiff and handle well. Probably not the most aero though.

I thought the Kysriums were great... for keeping you cool with all the air they push around :p

It is supposed to be Newton/mm
1.0 newton(N) = .1019716 Kg a unit of force.
mm is a unit of distance.
Higher number means that it takes more force to move the rim the same distance.
I think that is what you were asking.
As the rider and bicycle are working together, you also need to think about all contributions of the small amount of power that the rider can generate and how it can be effectively and efficiently converted to move in the desired direction. The rim may move 1 mm laterally, but the response of the tires is usually much larger and can contribute to measureable and possibly significant power loss. It certainly doesn't seem to bother the best sprinters who are generating 1,000 Watts or more in their sprint to the finish, but they can do things that most humans only can ponder.

daveornee said:

It is supposed to be Newton/mm
1.0 newton(N) = .1019716 Kg a unit of force.
mm is a unit of distance.
Higher number means that it takes more force to move the rim the same distance.
I think that is what you were asking.
As the rider and bicycle are working together, you also need to think about all contributions of the small amount of power that the rider can generate and how it can be effectively and efficiently converted to move in the desired direction. The rim may move 1 mm laterally, but the response of the tires is usually much larger and can contribute to measureable and possibly significant power loss. It certainly doesn't seem to bother the best sprinters who are generating 1,000 Watts or more in their sprint to the finish, but they can do things that most humans only can ponder.

Thanks Dave. I think as someone pointed out, the major problem of wheel flex as I see it is when it starts hitting the brake pad. That is a very noticeable way of cutting your power. I have experienced this, though not through wheel flex, but due a calliper problem. Amazing how those brakes slowed me down, who would have thought... 🙄

Before this thread I was totally on the fence as to which rims to use for my new wheelset. Now I know. Deeper and slightly heavier rim, here I come! 🙂 To my chagrin....diet, here I also come! 🙁