On Monday, 10 August 2015 22:23:38 UTC+10, AMuzi wrote:
On 8/9/2015 4:09 PM, mark cleary wrote:
I know this has been hashed a zillion times but this group
has personalities so I ask. All the press-fit stuff to mean
is basically garbage for stability and ease of maintenance,
much less the creaks. Are BSA threaded BB done and over with
and do I just need to get use to, figuring out how to work
on and be comfortable with press fit frames? I just see this
as a way to cheapen the process. To just give a bit of
background I repair and play guitars. I myself work and play
some of the most classic jazz guitars around and I see the
newer makers of jazz guitars cutting corners to make things
easier. Just quite using inlay, layers of binding, and
certain designs because frankly.............it makes it
easier to build. Oh sure you drop and few ounces of weight
but I made up for it by simply taking less stuff on the bike.


Deacon Mark Cleary
Epiphany Roman Catholic Church


It's complex, probably not nefarious.

Yes carbon lends itself to a non-threaded format. Yes, there
are plenty of builders still producing threaded frames. Both
formats exist across an incredible range of quality and
price. Although one might assume a non threaded frame is
cheaper it's not at all clear that it's a significant expense.

Then we have the crank makers, whose business is getting
their part on new bikes, a couple days of which are bigger
volume than a year's worth of aftermarket. Assembly time is
a big factor in adoption of press systems.

And although one does hear of noises and assembly issues
with press type frames, there's a hundred years of threading
troubles too. The load, torque and precession around a BB is
non-trivial and neither system is perfect.

--
Andrew Muzi
www.yellowjersey.org/
Open every day since 1 April, 1971

Thing is, you can remove and replace threaded systems til the cows arrive back for milking: no significant damage if done correctly. Press fit: even if replaced correctly, by iteration about 3-6 you will reaching for the bearing retaining compound, due to the ripping of a very thin layer of bearing seat material off the ID of the frame. Pressfit on bikes = designer (engineer reluctantly following) admitting that their frames are throwaways. Not for this little black duck.