Poor truing, or bent rim?



D

Dukester

Guest
I'm waiting on Brandt's book to come in so don't curse me for not reading it
yet but in the meantime I'm doing without and trying to true the front wheel
off an old Schwinn hybrid, mainly for practice, but also because I want to
get this bike fitted for use on some gravel roads near where I live. It was
pretty "wobbly" when I started, not sure I ever paid much attention before.
As several of the spoke nipples were "frozen" and the nickel stripped so I
couldn't turn it, I ended up nipping the spokes and replacing with stainless
steel nipples. I didn't want to fight the nickel stripping so I replaced
all the nipples with new SS ones.

Starting with all loose spokes, and following Sheldon's page on truing I am
running into 2 places where the wheel simply seems to stay out of true.
Except for these 2 spots the thing is pretty darn good. I've loosened and
started over several times (did I mention several times??), but always in
these same 2 places where there is large "wobble", maybe as much as 5mm!?
The spokes in these 2 areas get to the point where they are tight, too tight
really, and I still can't get that wobble out. Is it possible the rim is
just bent or damaged enough that I can't visibly see it, but it throws the
truing off?

Cheers!
Dukester
 
Dukester said:
I'm waiting on Brandt's book to come in so don't curse me for not reading it
yet but in the meantime I'm doing without and trying to true the front wheel
off an old Schwinn hybrid, mainly for practice, but also because I want to
get this bike fitted for use on some gravel roads near where I live. It was
pretty "wobbly" when I started, not sure I ever paid much attention before.
As several of the spoke nipples were "frozen" and the nickel stripped so I
couldn't turn it, I ended up nipping the spokes and replacing with stainless
steel nipples. I didn't want to fight the nickel stripping so I replaced
all the nipples with new SS ones.

Starting with all loose spokes, and following Sheldon's page on truing I am
running into 2 places where the wheel simply seems to stay out of true.
Except for these 2 spots the thing is pretty darn good. I've loosened and
started over several times (did I mention several times??), but always in
these same 2 places where there is large "wobble", maybe as much as 5mm!?
The spokes in these 2 areas get to the point where they are tight, too tight
really, and I still can't get that wobble out. Is it possible the rim is
just bent or damaged enough that I can't visibly see it, but it throws the
truing off?

Cheers!
Dukester
I didn't know there was such a thing as stainles steel nipples. Are you sure that they are not just new brass nipples with silver color (nickel) plating?
Stainless steel male and female threads gall quite easily when tightened.

Yes, your rim can be bent so much that trying to true it with spoke tension will give the results you describe.
You can detension it and try to straighten it with blocks of wood, hammer, pliers, etc. I don't do this at the shop any more as I find the results are not satisfactory in the long run (or even the short run most of the time).
When you are finished the spoke tension should be balanced near the same point where true is.