Tensiometer curiosity

[jim beam]

Ron Ruff wrote:
> On Mar 31, 11:23 am, jim beam <[email protected]> wrote:
>> maybe it's because jobst never builds with welded rims. /my/ experience
>> is that welded rims need over-tension. and i would expect that if
>> excess weld material makes that section more rigid.
>
> The change in curvature between a built and unbuilt wheel is going to
> be very small, though. I'd wager that it depends on how the rim was
> distorted when the joint was put in... could go either way.
>
in theory, yes. as pointed out by others, there's often a tiny flat
spot where the weld flashing is machined off, and using a truing stand
like a ts2 doesn't exactly emphasize the problem, but with every welded
rim i've built, it's needed higher tension for the 2 spokes at the join.
i build with an attachment to my ts2 so i have a proper handle on radial
trueness, not just lateral, which is all that stand really does.

 

[Ozark Bicycle]

On Apr 1, 11:35 am, jim beam <[email protected]> wrote:
> Ron Ruff wrote:
> > On Mar 31, 11:23 am, jim beam <[email protected]> wrote:
> >> maybe it's because jobst never builds with welded rims. /my/ experience
> >> is that welded rims need over-tension. and i would expect that if
> >> excess weld material makes that section more rigid.
>
> > The change in curvature between a built and unbuilt wheel is going to
> > be very small, though. I'd wager that it depends on how the rim was
> > distorted when the joint was put in... could go either way.
>
> in theory, yes. as pointed out by others, there's often a tiny flat
> spot where the weld flashing is machined off, and using a truing stand
> like a ts2 doesn't exactly emphasize the problem, but with every welded
> rim i've built, it's needed higher tension for the 2 spokes at the join.
> i build with an attachment to my ts2 so i have a proper handle on radial
> trueness, not just lateral, which is all that stand really does.



Your TS-2 is different, then, from any other I have seen or used (?).

 

[jim beam]

Ozark Bicycle wrote:
> On Apr 1, 11:35 am, jim beam <[email protected]> wrote:
>> Ron Ruff wrote:
>>> On Mar 31, 11:23 am, jim beam <[email protected]> wrote:
>>>> maybe it's because jobst never builds with welded rims. /my/ experience
>>>> is that welded rims need over-tension. and i would expect that if
>>>> excess weld material makes that section more rigid.
>>> The change in curvature between a built and unbuilt wheel is going to
>>> be very small, though. I'd wager that it depends on how the rim was
>>> distorted when the joint was put in... could go either way.
>> in theory, yes. as pointed out by others, there's often a tiny flat
>> spot where the weld flashing is machined off, and using a truing stand
>> like a ts2 doesn't exactly emphasize the problem, but with every welded
>> rim i've built, it's needed higher tension for the 2 spokes at the join.
>> i build with an attachment to my ts2 so i have a proper handle on radial
>> trueness, not just lateral, which is all that stand really does.
>
>
>
> Your TS-2 is different, then, from any other I have seen or used (?).
>
it only comes with calipers that run for a wheel's lateral dimension.

http://parktool.com/images/products/productimages/spr_TS_2BIGB_2005616_307.jpg

you can "see" roughly where radial is, but it's not as good as having a
true radial caliper, which i what i added to mine. a popsicle stick
held on with a magnet is a cheap alternative.

 

[Ozark Bicycle]

On Apr 1, 9:42 pm, jim beam <[email protected]> wrote:
> Ozark Bicycle wrote:
> > On Apr 1, 11:35 am, jim beam <[email protected]> wrote:
> >> Ron Ruff wrote:
> >>> On Mar 31, 11:23 am, jim beam <[email protected]> wrote:
> >>>> maybe it's because jobst never builds with welded rims. /my/ experience
> >>>> is that welded rims need over-tension. and i would expect that if
> >>>> excess weld material makes that section more rigid.
> >>> The change in curvature between a built and unbuilt wheel is going to
> >>> be very small, though. I'd wager that it depends on how the rim was
> >>> distorted when the joint was put in... could go either way.
> >> in theory, yes. as pointed out by others, there's often a tiny flat
> >> spot where the weld flashing is machined off, and using a truing stand
> >> like a ts2 doesn't exactly emphasize the problem, but with every welded
> >> rim i've built, it's needed higher tension for the 2 spokes at the join.
> >> i build with an attachment to my ts2 so i have a proper handle on radial
> >> trueness, not just lateral, which is all that stand really does.
>
> > Your TS-2 is different, then, from any other I have seen or used (?).
>
> it only comes with calipers that run for a wheel's lateral dimension.
>
> http://parktool.com/images/products/productimages/spr_TS_2BIGB_200561...
>
> you can "see" roughly where radial is, but it's not as good as having a
> true radial caliper

Huh? The existing caliper, as designed and supplied, is easily used as
a radial indicator.

In the Park photo you linked to, the caliper will "read" *both*
lateral and radial runout when positioned as shown.


>, which i what i added to mine. a popsicle stick
> held on with a magnet is a cheap alternative

What's a popsicle stick going to do for you?