How do you maximise NDS spoke tension?

Discuss light weight issues concerning road bikes & parts.
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fast700c
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by fast700c

Hi, for a standard 2 or 3 cross rear wheel build is there any way you can get a higher spoke tension on the NDS.
I've just built my first set of wheels (powertap 2X) and if I understood SPOCALC properly it indicated I would only get 55% percent spoke tension on the NDS which worked out about right.
115-120kgm DS, 60-65kgms NDS. Does this sound about right or have I done something wrong. The wheels look good and spokes feel tight when stress relieving I'm just wondering if thats going to be to loose.
I get my new bike later this week so haven't ridden the wheels yet but don't want a set of wheels where the spokes loosen up.
Thanks and before anyone asks, I did search.

by Weenie


Phill P
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by Phill P

For the wheels you have the only way to increase NDS tension is to increase DS tension. You are balancing the lateral forces left and right, so if tighter on one side you have conter with more on the other. You already seem fairly tight on the DS, so you may just have to live with the NDS tension. Besides adding 20kgm on the DS will only result in 10kgm on the NDS. The increased risk of fatigueing spokes doesn't seem worth it for what you get in NDS tension.

You have nice wide flanges it would seem, and you could go triplette. Half as many NDS spoeks would equal out the tensions.
Other solution is to have a narrower NDS flange hwere you have say 70% of the DS tension on the NDS instead of 55%.

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synchronicity
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by synchronicity

Thinner-gauge nds spokes.
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fast700c
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by fast700c

synchronicity wrote:Thinner-gauge nds spokes.


I'm using CX-rays all around.
Sounds like I'm right to go then with those tensions.

rruff
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by rruff

Phill P wrote:You have nice wide flanges it would seem, and you could go triplette. Half as many NDS spoeks would equal out the tensions.


The flanges are not very wide at all... it's just that the DS flange is ~17mm from center and the NDS is ~32mm. Triplet will work but cutting the number of NDS spokes in half will have a big impact on lateral stiffness. Triplet works best on a very wide flanged hub.

Probably the best way to lace one of these is 1x heads in on the DS, and 2x on the NDS... that makes the effective DS flange spacing ~19mm. 2x both sides is fine too... I wouldn't worry about the 60kg tension on the NDS as that is normal for many hubs and wheels.

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ergott
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by ergott

synchronicity wrote:Thinner-gauge nds spokes.


That doesn't change the tension. Tension is determined by the geometry of the components. Thinner gauge spokes will be slightly better at preventing spoke at lower tension from going slack.

OP:
If you haven't already built the wheel up, the 2X/1X lacing will decrease the difference in tension between the two sides as mentioned above.

By the way, 55% difference isn't that bad. If you already built up the wheel, you will be fine so long as the wheel is built well. Go with the highest tensions the rim will comfortably take.

-Eric

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synchronicity
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by synchronicity

ergott wrote:
synchronicity wrote:Thinner-gauge nds spokes.


That doesn't change the tension. Tension is determined by the geometry of the components. Thinner gauge spokes will be slightly better at preventing spoke at lower tension from going slack.


In that case, what's the difference between using nds spokes with half the cross sectional area in a conventional lacing pattern and a campagnolo-esque G3 spoking pattern with half the number of nds spokes?
Vertebrae. Precision braking and shifting.

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legs 11
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by legs 11

Half the number of NDS spokes means the dish tension is divided between less spokes effectively doubling the pull on each one, hence...more tension applied to each nipple meaning less likelyhood of a nipple loosening.
Reducing the gauge of the NDS spoke without reducing the spoke count or lacing pattern has little or no effect on the ratio between the two sides, it just means you can save a little bit of weight as the NDS spokes aren't working very hard anyway so why have the same cross section as the DS?
It's all about flange spacings, spoke count side to side and lacing patterns using either heads in or out to get the widest bracing angle with the minimum difference between the two flange distances from the hub centre.
mmmmmm? complicated stuff. :?
To the OP, I think you've done well to get that split of tension between the sides.
Something to remember though, is that when you get to a certain point the DS tension isn't so effective in pulling tension into the NDS, much above 100kgf and an extra 10 kgf won't make much difference at all.
I try to pull the dish into the wheel using the NDS nipples as late as possible in the build as it reduces the chance of rounding a nipple...not sure if it's in my head but that seems to give a little bit extra on the NDS.
Pedalling Law Student.

rruff
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by rruff

synchronicity wrote:In that case, what's the difference between using nds spokes with half the cross sectional area in a conventional lacing pattern and a campagnolo-esque G3 spoking pattern with half the number of nds spokes?


It reduces the chance of a NDS spoke coming loose from radial loads, but it has little effect on the lateral situation. It is often a good idea to put thicker spokes on the DS, if you are using a shallow rim that is radially flexible.

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Danton
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by Danton

legs 11 wrote:I try to pull the dish into the wheel using the NDS nipples as late as possible in the build as it reduces the chance of rounding a nipple...not sure if it's in my head but that seems to give a little bit extra on the NDS.

Sounds like you are an artist.

To the OP, all the solutions above make sense. Is this not the reason behind the differential drilling on the Campagnolo rims, like the Neutrons?

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legs 11
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by legs 11

@Danton, no not an artiste really, just someone who has noticed differences in building methods.
I've got three rears to do in the next couple of days all the same parts and tensions so I'm going to try the opposite on one and see if it really does make a difference in the finished tensioned wheel.
I think it may be fairy dust but it could be interesting if you're into that sort of thing? :D
Pedalling Law Student.

fdegrove
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by fdegrove

legs 11 wrote:@Danton, no not an artiste really, just someone who has noticed differences in building methods.
I've got three rears to do in the next couple of days all the same parts and tensions so I'm going to try the opposite on one and see if it really does make a difference in the finished tensioned wheel.
I think it may be fairy dust but it could be interesting if you're into that sort of thing? :D


Hi,

Don't bother.
I work the same way as you do and that's how I obtain the best results.

Ciao, :wink:
Being a snob is an expensive hobby.

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Amadeus
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by Amadeus

I second Legs 11 and Fdegrove
My bike is Italian so it is Nervosa and of course has Anorexia I like them thin!
GIOS "New" Carbon Ultra 2006 Campa Record+Special parts.
GIOS "New" A90 2008 Campa Record+Special parts. My winter and vacation bike.

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strobbekoen
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by strobbekoen

There will be no difference in the finished tensioned wheel. For a certain spoke configuration, tension is tension. Personally I prefer to get the dish right first at relatively low even spoke tensions, then get it true, and then raise the spoke tensions making small corrections on each cycle.

by Weenie


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