Need help for a weel build

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PeterKim
Posts: 12
Joined: Mon Mar 26, 2018 11:09 am

by PeterKim

Hi everyone, recently I did some indeaft research about spoke patterns. For a few years I thought the radial on the front and the 2:1 pattern for the rear hub was the best performance pattern for a rim beake wheel. But when I did my research some people stated that the 2:1 compromised the lateral stiffness of the rear wheel. Also, the spoke count varies between the weight of the rider, the rideimg situation, and the rim stiffness. So, what do you think is the best spoke pattern and count for a 60kg rider who rides at okey road, that whant to use a 50mm carbon rim, enjoys weekly hc level climbing, weekly group rides at varying terrain, and uses rim brakes. Of course the spokes will be cx-ray. Or is 50mm to deep for me

by Weenie


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Marin
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Location: Vienna Austria

by Marin

2x / 2x

2x on the left too, because it will give slightly higher tension, and will allow lacing over/under to prevent 0 tension situations.

PeterKim
Posts: 12
Joined: Mon Mar 26, 2018 11:09 am

by PeterKim

Marin wrote:
Tue May 08, 2018 8:51 am
2x / 2x

2x on the left too, because it will give slightly higher tension, and will allow lacing over/under to prevent 0 tension situations.
Are you suggesting the 2:1 or non 2:1 pattern for the rear wheel?
Because as you know it is possible to cross the non drive side of the 2:1 pattern


alcatraz
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Joined: Mon Aug 29, 2016 11:19 am

by alcatraz

There are many ways to make a wheel. I think you are obsessing a bit too much over the pattern. Some people just like the looks of a certain pattern over another. :lol:

Being lightweight you have a broad range of options. If you can find a good deal on hubs then use whatever pattern that works best with those hubs.

Now if saving money is no object then for me personally I'd like extralite spt rear hub and sp front. Rear hub uses straight pull spokes in a 2:1 fashion. I'd use Pillar Megalite SS spokes at 3.5gr each @260mm. :D

Marin's suggestion works fine and is very common for wheels. It has very few weaknesses, if any. I had a wheelset running 2x DS and radial NDS (12+12h) and the problem there is that a larger/stronger rider or a rider using very lightweight spokes could "overstress" the DS spokes in such a configuration. Those 12 (more accurately the 6 pulling ones) spokes need to be tensioned properly and be the right size and length. With Marin's suggestion you will have 12 pulling spokes which is good for torsional loads. I guess you just need to take care not to overtension the DS spokes or undertension the NDS spokes.

For an ultralight build I like 2:1 lacing because 16 spokes on the drive side sounds good to me and should be fine with very thin/light spokes.

PeterKim
Posts: 12
Joined: Mon Mar 26, 2018 11:09 am

by PeterKim

Marin wrote:
Tue May 08, 2018 11:11 am
No, 1:1.
Oh, thanks for the suggestion

PeterKim
Posts: 12
Joined: Mon Mar 26, 2018 11:09 am

by PeterKim

alcatraz wrote:
Tue May 08, 2018 2:42 pm
There are many ways to make a wheel. I think you are obsessing a bit too much over the pattern. Some people just like the looks of a certain pattern over another. :lol:

Being lightweight you have a broad range of options. If you can find a good deal on hubs then use whatever pattern that works best with those hubs.

Now if saving money is no object then for me personally I'd like extralite spt rear hub and sp front. Rear hub uses straight pull spokes in a 2:1 fashion. I'd use Pillar Megalite SS spokes at 3.5gr each @260mm. :D

Marin's suggestion works fine and is very common for wheels. It has very few weaknesses, if any. I had a wheelset running 2x DS and radial NDS (12+12h) and the problem there is that a larger/stronger rider or a rider using very lightweight spokes could "overstress" the DS spokes in such a configuration. Those 12 (more accurately the 6 pulling ones) spokes need to be tensioned properly and be the right size and length. With Marin's suggestion you will have 12 pulling spokes which is good for torsional loads. I guess you just need to take care not to overtension the DS spokes or undertension the NDS spokes.

For an ultralight build I like 2:1 lacing because 16 spokes on the drive side sounds good to me and should be fine with very thin/light spokes.
Yes, I am obsessing over the pattern. I whant my bike perfect as I can. Thank you for opening my eyes to Piller spokes and Extralite hubs. :D

alcatraz
Posts: 4064
Joined: Mon Aug 29, 2016 11:19 am

by alcatraz

Because of the dishing all rear wheels are inherently unstable. Torsional load on only one side doesn't help either.

Some lacing patterns try to work with these issues. No pattern is perfect. I think this is the reason why you can see so many curious funky lace patterns on rear wheels.

/a

PeterKim
Posts: 12
Joined: Mon Mar 26, 2018 11:09 am

by PeterKim

alcatraz wrote:
Tue May 08, 2018 11:41 pm
Because of the dishing all rear wheels are inherently unstable. Torsional load on only one side doesn't help either.

Some lacing patterns try to work with these issues. No pattern is perfect. I think this is the reason why you can see so many curious funky lace patterns on rear wheels.

/a
If the torsional load at one side is the issue then dos crossing the non drive side at least make it the situation better? Or is there a fallowing issue if I do that.

alcatraz
Posts: 4064
Joined: Mon Aug 29, 2016 11:19 am

by alcatraz

This is way over my head really. Maybe there is an article on it somewhere... I'd like to learn more too.

Certain hubs can be a problem with torsional loads. They can actually break if the torsional stiffness between ds and nds is unbalanced.

To answer your question, I think it would help. Crossed on both side is what I see a lot on high end wheels. Sometimes 3x DS 2x NDS but most of the time I think it's 2x DS 2x NDS.

The more crosses you got, the smaller a portion of the spoke tension is going to lateral stiffness and more is going into torsional stiffness. Because dished wheel DS spoke tensions normally are so high and NDS are so low, the intuition is to do more crosses on the NDS side to balance out the spoke tension. This would however make the NDS more torsionally stiff than the DS and stress the hub.

So to sum it up. The 2x : radial example I mentioned in my previous post has no torsional stress on the hub. Marin's example has nearly no stress (i think) and helps to balance ds/nds spoke tensions a little. It's probably the best commonly found configuration out there which means good looking for parts/learning building. I still like the idea of 2:1 though with 2x : radial for light riders and light builds but as you've noticed, patterns are somewhat of a personal taste for some. :D

/a

bm0p700f
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by bm0p700f

Take a normal hub with 17/37mm spacing and a 2:1 hub. the lateral stiffness of the 2:1 hub will be greater if the NDS to centre spacing is greater than ~45mm. If the flange is further inboard then you have wasted time with 2:1 lacing.

Also under/over lacing does not prevent zero tension situations. 2:1 lacing has the advantages if used in tubeless ready wheels as the tubeless tyres can cause savage tension drops and the higher NDS tension is therefore useful.

The ideal 2:1 lacing hub has flange spacing of 17/50mm and you use an asymmetric rim with it. That is something I hope to bring to market next year. I have alot of pennies to save first to get the hubs produced (500 min) and the rims.

shimmeD
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Location: eNZed

by shimmeD

I think you've posted before but can you pls reiterate the spoke tension ratio NDS to DS of 'normal' 2:1 hubs 17/37 vs your special?
Less is more.

bm0p700f
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by bm0p700f

Simply ratio the flange spacings and your pretty much there

For the special the 3mm offset makes it 20/47mm but double the NDS tension of course.

2:1 lacing does not have to be equal tension either side. That desire compromises the wheel and you loose the benefits you could have.

So 46% balance vs 85% balance.

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WinterRider
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Joined: Tue Feb 05, 2013 2:46 pm

by WinterRider

Always.... with the lateral stiffness comedy per 2/1 lacing. :noidea:

If you lace the 2/1 rear 3x DS with either radial or 1x outside left you will have a stiffer unit that 99% of all riding a bike could ever require.

G3's.. the Campy 14/7 lacing.. many in use professionally. Same thing just 3 less spokes.

Go to the bike shop and look at some of the high end mass produced stuff... look at the rear wheels.. what do you see? Usually 2/1's..........
Litespeed 2000 Appalachian 61 cm
Litespeed 1998 Blue Ridge 61cm

Fitness rider.. 1 yr from seven decades age.

That is my story and I'm stick'n to it.

bm0p700f
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by bm0p700f

a back of the envelope (spreadsheet) calculation of the relative lateral stiffness of two wheels
1) with 17/37mm hub spacing 44/45mm PCD (DA9000) and 580mm ERD 24H 3mm offset (I let you guess which rim)
2) with 17/49mm hub spacing 46mm PCD and 580mm ERD 3 mm offset 16:8 (24H) NDS laced radially so 2.5mm subtracted from NDS spacing as I am hoping for a forged hub with classic flanges.

The 2nd wheel is 6.66% stiffer laterally. The tipping point is actually when the NDS flange is 45.805mm from the centre.

So that is what I have been getting at.

by Weenie


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