# pieces of velox vs. uncut strip...



## cwg_at_opc (Oct 20, 2005)

while i'm waiting for new tubes and skins for my newly arrived wheelset
(Korso), i was thinking about rim strips. specifically, is there any value
in cutting velox into pieces just large enough to cover the spoke holes,
or am i just wasting my time? theoretically, i'd be reducing the rotating
mass by some stupidly small amount, but it might make spoke repair
easier, no? granted, i'm not using a wheelset that'd be worth every
microgram(nor am i racing) but it's an interesting thought excercise.
any comments from the weight weenies?


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## Kaboom (Jul 18, 2003)

honestly, i think you're wasting ur time. Rim strip is cheap enough to be considered disposable, and really how much does rim strip weigh? 10 grams per wheel? excellent, u'll be saving 5 grams per wheel. You can loose that weigh but putting slightly less air into the tires (didn't tracksters inflate their wheels with helium?).
Plus getting small, unconnected parts of rim strip to stay in place will be a pita.
but this is just my (probably uneducated) opinion.
cheers!


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## gambo2166 (Oct 20, 2004)

*Veloplug!!!*

This is what I use you can loose over 20 grams for just a few dollars. http://www.velocitywheels.com/accessory.htm


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## cwg_at_opc (Oct 20, 2005)

*veloplugs*

yeah, looked at these things, but it seems like cloth will still be softer
and less 'pokey' to any tube i'll be using. interesting idea though.

finally found the official weight weenies(<a href=http://weightweenies.starbike.com/phpBB2/> forum</a>) and i'm not the only one
who thought of this; it does seem a bit excessive though, i.e. too
much work for a few grams. maybe if i'm <i>really</i> bored i'll try
my new front wheel both ways and do a few tests...

thanks for the replies so far!


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## rensho (Aug 5, 2003)

Fiberglass packing tape from your home improvement store. 2 layers ought to do it. Cheap and no more than 3g per wheel.


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## cwg_at_opc (Oct 20, 2005)

*velox*

i decided not to tempt fate, and at the same time try a little
experiment, which may not work out so well. i cut up some
velox(green) and laid them in over the spoke holes, and by
the time i got half-way around the wheel, two(out of about 10)
had come loose. i'm not sure if the tape is too big despite
being cut(ie. still too wide for the narrow channel at the bottom
of the rim), or if the sticky stuff is old. i used a tire lever to
'burnish'?/rub/press the tape onto the rim and it finally stayed put.
as for the other wheel, i just laid the whole strip in as designed.
time will tell.

the LBS only has the green Velox and some really thin/narrow Velox
that looked to be about as wide as the spoke holes, so i
passed on that roll. isn't there a blue velox? the green seemed
a bit wide.

p.s. the wheel is the Supergo Korso, which is a narrow, semi-aero
section rim. i'll try to measure the rim width inside if i can remember.


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## austex (Sep 20, 2004)

Let us know if this works. I'd expect not, as the rim strip relies on tensile continuity to resist 100psi pressure. Maybe you could cut out every other inch of the tire bead, too, to save more weight by just leaving the tread intact.


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## geraldatwork (Jul 15, 2005)

cwg_at_opc said:


> yeah, looked at these things, but it seems like cloth will still be softer
> and less 'pokey' to any tube i'll be using. interesting idea though.
> 
> finally found the official weight weenies(<a href=http://weightweenies.starbike.com/phpBB2/> forum</a>) and i'm not the only one
> ...


When I received my Velocity wheels they sent me some plugs. I didn't bother using them, ( I'm a little more trational minded) I put a few plugs in the holes and gather they would work well. I also put the tape in one hand and 32 plugs in the other and the plugs were definately lighter. Also if you needed to repair a spoke it certainly would be easier. One of the things they push is that it might make the tire a little easier to put on the rim as it would take up less room than the tape. Many reasons to use them but I went for the tape anyway.


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## TZL (May 4, 2005)

Supergo Korso's are great wheels, they are cheap, and strong, but they are super heavy !

mine weigh in at 1820 grams a pair.........I don't know why you would bother trying to save 5-10 grams on them. Just use them, and save your money and efforts for a lighter set of wheels.


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## gambo2166 (Oct 20, 2004)

The plugs work great!!! Cheap, light and it makes it ez to mount your tires.


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## cwg_at_opc (Oct 20, 2005)

*rode them today...*

...they seemed pretty stiff, spun up nicely, not sluggish at all.
out-of-saddle climbing on some of the hills went well, they felt very
efficient, each pedal stroke went directly to the ground. the most
surprising thing is how absolutely quiet they are when coasting!
i guess i'll have to go weigh mine so we can compare. at any rate,
they feel livelier than the old set, and they've got to be more than
a half-pound lighter.

for those of us who are returning to riding(me) or are feeling the sorry
effects of getting older(me too ;-) the weight weenie thing is more a
mental excercise than anything else when it comes to a few grams.
don't you feel happier when you know you've cut a few grams? it
makes me want to ride more! for those times that i can actually feel
the difference, it's nice to know i've done the right thing weightwise.
so, yeah, i'll save my pennies for a wheelset from somebody like
Mike Garcia(oddsandendos.com), but for now i'm happy to nickel
and dime my way to lower wieght.



TZL said:


> Supergo Korso's are great wheels, they are cheap,
> and strong, but they are super heavy !
> mine weigh in at 1820 grams a pair.........I don't know why you would
> bother trying to save 5-10 grams on them. Just use them, and save
> your money and efforts for a lighter set of wheels.


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## cwg_at_opc (Oct 20, 2005)

*update*

Ah, well. i can honestly say i can't tell the difference between a complete
strip and cut sections. if i had the time, i suppose i could hack up a test
rig to actually measure the time it takes to spin up a wheel given a set
force(torque), and then how long it spins before stopping(inertia v friction)
at least the new wheels _feel_ nice.



cwg_at_opc said:


> ...they seemed pretty stiff, spun up nicely, not sluggish at all.
> out-of-saddle climbing on some of the hills went well, they felt very
> efficient, each pedal stroke went directly to the ground. the most
> surprising thing is how absolutely quiet they are when coasting!
> ...


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## TZL (May 4, 2005)

I would have guessed that you can't feel any difference...... a complete Velox strip weighs 15g, so yours probably weighs 5g, so i'd guess you saved 20 g total between the two wheels........



cwg_at_opc said:


> Ah, well. i can honestly say i can't tell the difference between a complete
> strip and cut sections. if i had the time, i suppose i could hack up a test
> rig to actually measure the time it takes to spin up a wheel given a set
> force(torque), and then how long it spins before stopping(inertia v friction)
> at least the new wheels _feel_ nice.


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## winstonc (Nov 18, 2002)

I've actually done both the cut-strip thing and the veloplugs.

One of the reasons I cut up the strip is that I only had one strip on hand, but I had gotten two wheels (Korsos also). I used maybe 2/3s of a rim strip for both wheels -- they have only 16 and 20 spokes. I cut them with a large margin, so that they could slide around a little bit. They didn't stick all that well at first, but after peing pressed at 100PSI for a while, I think they'll be fine. They'll also set into the hole a little bit, so that they won't be able to slide around.

It's a little extra work, but it's not really that hard to take a length of rim strip and snip off some pieces. The fewer the spokes, the less work it is.
Anyway, it's held up fine for the last couple of weeks; I haven't had to do any tire changes though. I'll see then if it's still sticky.

My experience with the veloplugs is that they work as advertised. Mike at OddsAndEndos told me that they don't work very well with all rims since they don't all have the same sized holes... Obviously, they work with Velocity Aeroheads, but not with Mavic OPs or IRD Cadence. Supposedly they're coming out with different sizes of veloplugs for these other rims.


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## cwg_at_opc (Oct 20, 2005)

*test fixture*

so i was thinking about a test fixture and have come up with the following:

1 - put bike on bike repair stand, secure handlebars
2 - remove tires and tubes from front wheel
3 - get a known length of string, my guess is about 2feet long
4 - get a stopwatch, paper clip and a weight
5 - mount front wheel
6 - attach paper clip and weight to string
7 - make a 90 degree bend in paper clip
8 - put bend of paper clip in a spoke hole(it has to come out easily)
9 - spin wheel to wind up string, stop when weight is at 9 o'clock position
this will be the reference start for all additional runs
10 - release wheel and simultaneously start timing
11 - lap/mark when string comes loose of wheel, this is the spin-up time
12 - continue timing and stop when wheel stops entirely, this is the inertia
versus friction/drag time
13 - repeat ten(10) times and average

this should be run with:
- no tape,
- plugs,
- cut strips,
- uncut strip,
- and as much additional mass as you have the patience for. 

we can then graph the times against the mass and see what happens. i
predict that we will have difficulty seeing a significant difference at very
low masses, but the effects should be fairly obvious as the rotating mass
goes up. the question in the end will be at what point do you notice the
change in mass? certainly as the rides get longer or hillier, you'd want
to reduce rotating mass, but what is the point of diminishing return?
is it worth sacrificing reliability(no flats) for a few newtons?


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## winstonc (Nov 18, 2002)

cwg_at_opc said:


> so i was thinking about a test fixture and have come up with the following:
> 
> 1 - put bike on bike repair stand, secure handlebars
> 2 - remove tires and tubes from front wheel
> ...


I'm not really sure if this would yield valuable information. If I understand the setup correctly, the weight will be released at the same position on each run, but that doesn't mean the wheel will be going the same speed every time. It sounds like you want to measure the moment of inertia of the wheel... there are ways to do that:
http://www.physics.brown.edu/physics/demopages/Demo/solids/demos/1q1020.html
http://www.mne.psu.edu/undergrad/CaseStudy/ME50/TorsionalPendulum/casestudy.html#N4000A0

As you note, it would be hard to make any real-world conclusions from this sort of test. We already know that lighter is better for acceleration, but the tradeoffs (like reliability) are hard to quantify. What the math tells us is that mass at the edge of a wheel has twice the momentum and four times the kinetic energy of mass that's not rotating... so you could calculate the effect of a rim strip or tire or whatever, instead of measuring it directly.


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## cwg_at_opc (Oct 20, 2005)

<i>[puts on thinking cap]</i>
hmm. the wheel is not moving when we start, the reference weight at the end
of the string is pulled by gravity, spinning the wheel via the string as it falls to
the floor.

i guess i'm not using the right terms in the right places; doesn't measuring from
a dead stop to when the string is off the wheel measure the acceleration of the
wheel? this time should increase as the mass of the rim increases, i.e. more
mass takes more force to spin up; we're using the same weight on the string
and only changing the rim's mass.

hmm. the spin down time is less important, so maybe we can skip that part.
the time it takes for a spinning wheel to spin down to a stop measures
the rotational inertia/momentum, which as the rotating mass increases, the time
should increase as well. erk. we don't have a way to ensure that the wheel is
spinning at a reference speed before allowing it to spin down(unless we hand-spin
it and check the speed with a cycle-computer before letting it spin down)
that measurement would be good to know nonetheless. 



winstonc said:


> I'm not really sure if this would yield valuable information. If I understand the setup correctly, the weight will be released at the same position on each run, but that doesn't mean the wheel will be going the same speed every time. It sounds like you want to measure the moment of inertia of the wheel... there are ways to do that:
> http://www.physics.brown.edu/physics/demopages/Demo/solids/demos/1q1020.html
> http://www.mne.psu.edu/undergrad/CaseStudy/ME50/TorsionalPendulum/casestudy.html#N4000A0
> 
> As you note, it would be hard to make any real-world conclusions from this sort of test. We already know that lighter is better for acceleration, but the tradeoffs (like reliability) are hard to quantify. What the math tells us is that mass at the edge of a wheel has twice the momentum and four times the kinetic energy of mass that's not rotating... so you could calculate the effect of a rim strip or tire or whatever, instead of measuring it directly.


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## winstonc (Nov 18, 2002)

Yeah, you're right... I read it too quickly and thought that you were only going to pay attention to the spin-down time.




cwg_at_opc said:


> <i>[puts on thinking cap]</i>
> hmm. the wheel is not moving when we start, the reference weight at the end
> of the string is pulled by gravity, spinning the wheel via the string as it falls to
> the floor.
> ...


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## No Circles (Feb 12, 2005)

*Velo Plugs*

I have them on my wife's OP rims and they are fine with one caveat. Rim tape provides a smooth edge in the valve hole. After a cut valve stem I added a small piece of Vemox and that did not happen again. Plugs have been fine.

I tried to use them on my DT 1.1 rims but the hole shape is different and they did not snap in.

My two cents worth anyway.


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