Beat rim into true or not?

On 27 Jul 2005 07:43:45 -0700, wrote:

I SWEAR NO ONE WITH AN IQ UNDER 120 READS MY STUFF.

And here I thought datakoll's keyboard's shift key was broken. On
second thought perhaps it is and he just accidently hit the caps
lock key. ;-)

Oh yes...thanks for the compliment.


jeverett3ATearthlinkDOTnet http://home.earthlink.net/~jeverett3

Dammit ooops,
the poster writes that he's gonna bang on the rim all day with an
expletive deleted rubber mallet after i grind out 1000 words on hitting
a board laid atop the rim with anything.
then he's a gonna post in moaning that his rim won't go into true. this
is the dude rebending steel by starting at bothn ends and working
toward the middle
and give up and go into an unconscious state for the renmainder of his
existance.
i mean like not that i'm connected to the god head or nuthin' this is
terminal stuff here

i'm in pane

wrote:

i'm in pane

microdot?

Ape Petengail writes:

After a recent crash I have discovered a permanent bend in my front
rim, more of a single wave that extends about 1/4 of the way around the
rim. Laying the rim on the floor after disassembling the wheel, the
max out of true is ~1/4". There doesn't seem to be a kink in it,but
rather a smooth wave.

Would you beat on the rim with a rubber mallet or just bring it into
true with the spokes?

No, Do not use impact. The straitening of bent rims has been discussed
here often and is pictorially explained in "the Bicycle Wheel".

Generally, loosen the spokes uniformly about a turn or so each from
full tension and place the rim with the wow against the floor. Press
down with hands and knees on either side of the wow and assess
alignment as you carefully increasing the load. The wheel should
over-center when pushed down. Do this carefully and reverse the
direction if you overshoot. When short period wow's are straight, use
spoke truing for final alignment.

Jobst Brandt

jobst brandt wrote:

No, Do not use impact. The straitening of bent rims has been discussed
here often and is pictorially explained in "the Bicycle Wheel".

Generally, loosen the spokes uniformly about a turn or so each from
full tension and place the rim with the wow against the floor. Press
down with hands and knees on either side of the wow and assess
alignment as you carefully increasing the load. The wheel should
over-center when pushed down. Do this carefully and reverse the
direction if you overshoot. When short period wow's are straight, use
spoke truing for final alignment.

This may work for your MA2s, but I tried it with a couple of heavier rims
recently to no effect -- even if I stood with my full weight on the rim. I
had to resort to treating the rim as a first-class lever, with the
locations where you are describing pressing with your hands as the fulcrum.

Perhaps I'm just not heavy enough...

--
Benjamin Lewis

All what we got here is American made.
It's a little bit cheesy, but it's nicely displayed. -- FZ

Benjamin Lewis writes:

No, Do not use impact. The straitening of bent rims has been
discussed here often and is pictorially explained in "the Bicycle
Wheel".

Generally, loosen the spokes uniformly about a turn or so each from
full tension and place the rim with the wow against the floor.
Press down with hands and knees on either side of the wow and
assess alignment as you carefully increasing the load. The wheel
should over-center when pushed down. Do this carefully and reverse
the direction if you overshoot. When short period wow's are
straight, use spoke truing for final alignment.

This may work for your MA2s, but I tried it with a couple of heavier
rims recently to no effect -- even if I stood with my full weight on
the rim. I had to resort to treating the rim as a first-class
lever, with the locations where you are describing pressing with
your hands as the fulcrum.

I've used this with success to straighten all sorts of rims, be they
20" steel or 700c Aero. I won't make any predictions for non metal
rims, their yield nature being unpredictable and non-plastic. Of
course that's one of the great "advantages" of these materials... the
mystery and reliability.

Perhaps I'm just not heavy enough...

Maybe the spokes are not tight or loose enough. Too loose is like
working with a bare rim. It doesn't work. Too tight defies over
center flexing of the rim at the pint of interest.

Jobst Brandt

JB's 7/27 post is an abrieviated 'DIY rim repair tool 2' in tech
archives
the problem with knees and/or hammer/mallet is the knees do not hold
enough rim down or fix to locate the pressure needed to force the "wow"
back into line.
what knees and hand produce is more "ow"-from the knees and hands! and
from the rippled or waves of pressure at the "wow" impact area
using particle board to hold the say 340 degrees of relative non-wow
steady while bending the "wow" area's two points of deviation-departure
from the 340 more or less in an acceptable plane
reduces the problem areas-perception of normal and "wow" to a minimum
so the work actually proceeds straigth line not deviate into guess work
as to what to do next caws there's too many variable-as with knees and
hands.
fix? this is lining up the work?

jobst brandt wrote:

Benjamin Lewis writes:
This may work for your MA2s, but I tried it with a couple of heavier
rims recently to no effect -- even if I stood with my full weight on
the rim. I had to resort to treating the rim as a first-class
lever, with the locations where you are describing pressing with
your hands as the fulcrum.

I've used this with success to straighten all sorts of rims, be they
20" steel or 700c Aero. I won't make any predictions for non metal
rims, their yield nature being unpredictable and non-plastic. Of
course that's one of the great "advantages" of these materials... the
mystery and reliability.

Perhaps I'm just not heavy enough...

Maybe the spokes are not tight or loose enough. Too loose is like
working with a bare rim. It doesn't work. Too tight defies over
center flexing of the rim at the pint of interest.

Could be; I'll try fiddling with this the next time I have this problem.

--
Benjamin Lewis

All what we got here is American made.
It's a little bit cheesy, but it's nicely displayed. -- FZ

wrote:
using particle board to hold the say 340 degrees of relative non-wow
steady while bending the "wow" area's two points of deviation-departure
from the 340 more or less in an acceptable plane
reduces the problem areas-perception of normal and "wow" to a minimum
so the work actually proceeds straigth line not deviate into guess work
as to what to do next caws there's too many variable-as with knees and
hands.
fix? this is lining up the work?

Yah, this is what I did, only with 2x2's and sawhorses.

And BTW, Jobst, surprisingly, despite your admonishment about the use
of the mallet and other warnings, my rim is now true within ~1 mm and
seemingly not the worse for wear.

Perhaps there IS more than one way to remove the cat's pelt?

App