I have a KH 24" Muni and have similar problems. When I first put my uni
together (only around 3 weeks ago) I had a scraping sound when the wheel
rotated.
I must have been eating extra spinach or something that day, as the
reason for the scraping was my overtightening the bearing clamp bolts.
This caused the aluminium bearing cover to scrape on the bearing clamp
and to give the intermittent scraping noise.
Obviously, the way to fix this is to slacken off the clamp bolts then
re-tighten them until they just nip tight (ensuring that both cap-screws
are screwed in approximately equal amounts) and then to finally give
each about a quarter of a turn to lock them. After doing this I've not
had any scrape and, despite several off-road trips, the bolts have not
required re-tightening at all.
As regards other noises, I also have a 'click' noise. I hover left foot
down and almost since the first ride I've had a noise that seems to come
from the left side, but only when hovering (it either isn't there, or
goes unnoticed, during normal riding and hasn't yet appeared on the
right hand side). After much prodding and poking, the conclusion was
that it was definitely originating from the spline/crank area, but there
was no obvious movement or looseness when I tried to re-create the
problem by pushing and pulling on it by hand.
Being an obsessive engineer who is wary of damaging his beloved uni, I
stripped everything down as soon as I could, cleaned and oiled all
mating faces with WD-40 (don't know if this is a worldwide product name
- it's just a light oil in an aerosol can), then re-assembled
everything. This seemed to cure the problem and made me a happy man, but
unfortuantely the noise eventually returned.
I have discovered that if I gently tighten the crank clamp bolt (the big
one that you always hit your heel on), then gently tighten the pinch
bolt (the cap screw that clamps the crank around the hub splines) and
then alternate between tightening these two a little until everything is
absolutely tight, that this apparently solves the problem (or has done
so far anyway).
I didn't have any anti-sieze grease when I re-assembled my uni, or would
have used this on all screws/bolts/splines too. The use of anti-sieze
cured a similar problem on a friend's KH trials (these have the same
hub) and so, as I have now acquired some anti-sieze (thanks again
Roland), my job for tonight is to strip, clean, anti-sieze and
re-assemble The Beast in a final attempt to solve the problem for
good.
I'm also a little wary of the fact that the black paint that the cranks
are coated with also covers the mating faces where the crank interfaces
with the bearing/spacer/clamp bolt. The action of tightening the bolt
soon causes some paint to flake off in this area, which must cause an
imbalance (even a very small one) in the clamping load on the whole
stack. I'm concerned that this might also be adding to the problem and
so intend to stone these surfaces clean of paint before finally
re-assembling.
I'd be interested to hear if anyone else has any similar problems/fixes
as, as discussed in an earlier thread, it is bloody annoying to be
riding along and to hear a noise coming from your uni.
Gary
--
Gary.Kelsall - One of the BJC 2004 organisers
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