"Bleve" <[email hidden]> wrote in message
news:[email hidden]...
Quoted message said:
Here's what happens to the current Powertap SL 2.4 (RRP in Australia
of ~$2,700) hub after 1,500km of normal use with a 10sp Shimano
cassette (Ultegra).
http://www.aboc.com.au/images/galleries/20070509-saris-hub/
The photoset also has a comparison with a Dura-Ace Al alloy freehub
(the silver one that fits properly ...).
The Saris/Cyclops freehub is a bronze colour, and is clearly quite
badly damaged.
This is the same damage that occurs with any Al alloy freehub body
that's not designed to mate properly with Shimano 10sp. Bontrager
freehubs have the same problem, as do Easton/Velomax and I'm sure many
others.
Interestingly, American Classic realised the problem quite a while ago
and released some radial shims to fir their freehub bodies to reduce/
eliminate the problem.
The hub's being sent back to Saris with a 'please explain' (as well as
problems with intermittent data loss ... but that's another story!),
but I'm wondering, does anyone here recognise the freehub body from
some other hub manufacturer, and knows if a steel (or a properly
designed Al alloy ...) freehub could be swapped in? It has KHK stamped
on it. If Saris/Cyclops won't redesign the part, I'd like to fit a
steel freehub body so I can easily swap cassettes without needing two
chainwhips and a chisel.
That freehub looks the same at the Velocity hubs use. Of course, there are
probably a dozen other Taiwan hubs that use the same piece. I have seen the
cogs dig into the freehub before. There seems to be 2 factors that played
into that problem. First, separate cogs as opposed to a joined solid unit.
Second, the lockring was not tight enough.
No matter what, there is both a design and metallurgy problem occurring in
these freehubs. We usually keep a few spares around, just for ourselves.
As a side note, there is a real problem with the pawl springs on these
freehubs. They wear out rather quickly. Last weekend, one went on my wife's
Nuvian hub (Velocity). Here is a not so terrific, but effective fix: I
fabricated a new spring by unwinding and reshaping a coiled quick release
spring. I used two pliers to reshape the spring into what was needed. She
just took off for a ride and the freehub appeared to run normally. Let's see
if I catch hell later...
It has to work, we are riding downtown on Sunday to watch the race and then
to a brunch.
Having a freehub failure on Mother's Day is unthinkable ! LoL
In case anyone wants to know, there are two industrial bearings, separated
by a spacer tube inside these freehubs. I had to change them on a similar
unit a little while ago.
These freehub mechanisms are usually loaded with a green grease. I generally
change it out in favor of a light #1, #0 or even a synthetic oil. I believe
Peter has commented on using an oil many times. I definitely feel that is
the correct thing in a Shimano design. But in the Taiwan or Campy units, a
very light grease may stay in place better.
Bruce
