cartridge hubs on euro racers?

Jasper Janssen wrote:
On Sat, 22 Oct 2005 09:48:54 -0700, jim beam wrote:


[1] hydrodynamic separation of two surfaces sliding relative to one
another is different to elasto-hydrodynamic separation experience by
ball bearings at high speed. another example of hydrodynamic separation
is the journal bearings on the crankshaft of a car engine. at rest, a
car engine is high friction and hard to turn, but when running and the
hydrodynamic layer has initiated, friction is very low.


It's a lot easier to turn with the head off, though, which suggests
compression is not an insignificant contributor.

Jasper

literally, that's true for some guy cranking an engine by hand, but it's
not what i'm talking about jasper. i'm talking about the difference in
measurable friction between a journal bearing with and without
hydrodynamic separation. the example could be a turbine shaft, or one
of the multitude of other similar applications, but i'm trying to keep
it within the realm of stuff with which you're more familar. sorry for
assuming you'd figure that out.

On 22 Oct 2005 08:07:32 -0700, "Dave" wrote:


Anyway, it seems perfectly plausible to me. Trek pays for the wheels
so the mechanics have zero incentive to save money.

And Trek's funds are unlimited?

JT

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John Forrest Tomlinson wrote:
On 22 Oct 2005 08:07:32 -0700, "Dave" wrote:


Anyway, it seems perfectly plausible to me. Trek pays for the wheels
so the mechanics have zero incentive to save money.

And Trek's funds are unlimited?

No... but with any mass produced item the cost of making a few more is
quite small. The cost to Trek of an "extra" pair of $1500 wheels is
probably less than $100... maybe a lot less.

John Forrest Tomlinson wrote:
On 22 Oct 2005 06:29:27 -0700, "Qui si parla Campagnolo"
wrote:


Ron Ruff wrote:
Jasper Janssen wrote:
On 21 Oct 2005 09:20:38 -0700, wrote:

does lance et al. use ball and cone or cartridge hubs?

They ride Dura Ace or Record, I would imagine. I don't think they care
much whether it'scup/cone or cartridge.

Actually, I don't think they are using Dura Ace or Record hubs... most
teams have specific wheel sponsers, and use fancy lightweight carbon
rimmed wheels when they want to go fast. I'd wager that most of these
use cartridge bearings. Discovery at least, also replaces wheels after
a mere few hundred miles.

No Ron is right. They change wheels after a few stages...to keep
everything 'fresh'.

Are you guys saying a typcial Discovery Channel rider uses 25-50 pairs
of wheels a year (say 90 race days) and the rest are discarded or
sold by the team?

No way.

JT

That's what the wrench for the team said in the article mentioned.

Qui si parla Campagnolo wrote:
Ron Ruff wrote:
Jasper Janssen wrote:
On 21 Oct 2005 09:20:38 -0700, wrote:

does lance et al. use ball and cone or cartridge hubs?

They ride Dura Ace or Record, I would imagine. I don't think they
care much whether it'scup/cone or cartridge.

Actually, I don't think they are using Dura Ace or Record hubs...
most teams have specific wheel sponsers, and use fancy lightweight
carbon rimmed wheels when they want to go fast. I'd wager that most
of these use cartridge bearings. Discovery at least, also replaces
wheels after a mere few hundred miles.

No Ron is right. They change wheels after a few stages...to keep
everything 'fresh'.

If they age tubulars, the mechanics probably claim that the steel spokes "go
soft."
--
Phil, Squid-in-Training

huh!?! high speed?!? hydrodynamic separation?!?
generic 6001 series CB are rated 15,000~20,0000-rpm.
i figure 45-mph on a 700c (26 inch OD) is about 600-rpm or 4% rating.

well you know, you got cartridge bearings and you got cartridge
bearings:
http://tinyurl.com/7l7t8

B.C. Cletta wrote:
huh!?! high speed?!? hydrodynamic separation?!?
generic 6001 series CB are rated 15,000~20,0000-rpm.
i figure 45-mph on a 700c (26 inch OD) is about 600-rpm or 4% rating.


er, the speed rating is the speed at which a given temperature will not
be exceeded for a given load. that's got NOTHING to do with whether
there's any hydrodynamic separation of a seal.