“Ask MBA” peeve of the month:
Seized bottom brackets. They’re
Have a question for the MBA crew?
You can send your brain busters to
hours to make. It’s my favorite bike, and
no, you can’t buy it. John has since left the
bike-building world and, as far as I can tell,
is now an art teacher at a college in the
high country of Colorado.
That said, however, this was the first
cruiser-racer-style bike that came out of
the Black Sheep factory. It inspired those
guys to build a whole line of bikes that
are very similar to mine and equally cool.
If you’re looking for a bike like that, get in
touch with James Bleakley at Black Sheep.
He’ll hook you up.
Thanks for reading, and thanks for
taking the time to write in.
—Mike Wirth, editor
HOW MUCH SHOULD I PUMP?
Q: A bike-shop mechanic just told me
that I should pump my rear shock up to my
bodyweight, and that’s all I need to do to
tune my suspension, is that right?
—Trevor, who has a bad bike
A: The short answer is no. That’s not all
you need to do. Suspension designs are
all different. The required pressure varies
depending on shock air volume, leverage
ratios and damping adjustments. If you’re
looking for the simplest solution, set your
compression and rebound knobs to the
open setting. Then, set your sag, which is
the amount the shock compresses when
your bodyweight is in the riding position
to roughly 20–30 percent of the shock
travel. Once you’re there, you’ll have a
base setting. Now, you can start to work
on fine-tuning the air pressure and
damping adjustments to find your ideal
setup. Start with the rebound and
compression adjustments in the middle of
their ranges. Remember also that you can
always go back to your “base tune” if the
suspension starts working poorly.
BIG BOTTOM BRACKET QUESTION
Q: Is there a BB shell adapter that will
let me use a BB30 crankset with a 68-
millimeter threaded botton bracket
—Eric, who wants to put a big
bearing in a small hole
A: There isn’t one that we know of. The
BB30 requires a larger-diameter bearing
than your 68-millimeter BB frame, so
there’s no room to fit it all in there. Even
if there was a way to mount the bearings
outside of the BB shell, it would be tough
to find a crank with a spindle that would fit
that setup. Bottom line: the 68-millimeter
bottom bracket is on its way out. Sorry to
be the bearer of bad news. ❑
Ibis Ripley LS