What do you think of this wheel build?

Everything about building wheels, glueing tubs, etc.
Marin
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Location: Vienna Austria

by Marin

Again, the 190g Bitex will be more than adequate for a 52kg rider. I'm pretty hard on equipment.

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

by alcatraz

bm0p700f wrote:
Mon Oct 01, 2018 7:51 am
...
So 45-46mm nds flange position is good for triplet hubs.

What about 2x/2x 1:1 hubs? Any distance that is optimal there?

What about 0x/2x 1:1?

I live in China so I'd like to sort out the bad from the good. I've been eyeballing some hubs with interesting patterns:

1. 2x/2x triplet (unusual)
2. 0x/2x triplet

How can my 125kg friend's wheels stay true when the rear is only 24 spokes? I'm 90% sure he uses sapim cx-ray spokes and dt240 sp hub 2x/2x.

I have a good feeling that his spokes are experiencing large variations in tension as the bike rolls with his weight on it. Because of his large weight it's varying a lot. It means that if you have NDS spokes at 60kgf and they go below 30kgf at some point they might as well be completely slack. They do nothing. By raising the NDS tensions I think you raise the max weight limit, as long as the hub allows it. On his bike DS is 150kgf and I think NDS is 70-80kgf but to be honest I didn't measure NDS.

He manages to keep this wheel from failing by the strength of the hubflanges. Their solid construction help to minimize the risk of spokes going slack.

What's your guess?

by Weenie


bm0p700f
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by bm0p700f

Spoke life will be affected by DT Swiss design. The stiffer the wheel the smaller the tension changes there are. However bracing angle only affects the laterally stiffness. The effect on radial stiffness is quite small to non existent.

Flange pcd has almost no effect on stopping spoke going slack. Making the flanges larger dies reduces the tension changes from pedaling torque though or braking torque from disc brakes. It does nothing else. The effect on bracing andle is more than marginal.

It is quite easy to get a wheel to stay true. You thread lock the nipples so the nipples can't move.

2x/0x is not optimal for triplet. You want to get the D's spokes to be tangential to the D's flange to minimise tension changes from pedaling torque.

Nds spoke tension is a red herring. Focusing on that by it self is meaningless. Hubs with 17/37 to 17//40mm spacing seem optimal to me. Spoke tension does not affect stiffness. A DT Swiss road hub may have high nds spoke tension but it has lower lateral stiffness. The hubs I prefer have lower nds tension but higher lateral stiffness when built into a wheel. When people talk about this wheel is strong, they normally mean it is stiff.

The wheels are laterally stiff enough to stop spokes going slack.

I use miche Primato hubs. The flange spacing c-c for the rear is 56mm compared to DT Swiss 50mm. Tension balance of the miche hubs is 40% or is it 43% I forget but the point is spoke never seem to fail which is why all the focus on tension balance somewhat misses the point. The wheel has to be stiff enough to minimise spoke tension changes. That is how you maximise spoke life. There are things you can do with rim drilling e.t.c to prevent failure at the nipple end.

It's all basic physics. Fatigue is simply caused by length changes in the material and for a wheel you keep though down not by increasing tension but increasing lateral, radial and torsional stiffness.

Although high D's tension is needed still as this allows the wheel to retain enough tension when tubeless tyres are fitted for example. High tension also means very high sideliads can be applied with out slacking off spokes.

Offset rear rims are a nice solution to low tension balance. The expense is a 2% loss of lateral stiffness (contribution of spokes and bracing angle only) which is marginal. The gain though is a wheel that can take much higher sideloads and it is laterally still stiffer than what DT Swiss make.

So take the BORG31 rear wheel. With its offset rim (3mm) it has nds tension similar to what a DT Swiss hub gives but it is laterally stiffer so higher side loads can be taken in fact you can't load it to the point of spokes going slack.

With a DT Swiss hub and an offset rim you get very high nds spoke tension but as the rear wheel is laterally less stiff with the same rim and spokes you end up with larger tension changes from side loads even though it can take high side loads without spoke going slack.

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themidge
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by themidge

Am I right in thinking that the only difference between the bitex/BHS 190g hub and the 210g hub is the bearings? Any difference in stiffness? The dimensions appear to be the same.

If so, which of these rear wheel configurations (weights using 190g hub) should I go for?

kinlin xr19w 24 spokes 711g

kinlin xr19w 28 spokes 730g

kinlin xr200 28 spokes 710g

add on 20 grams to each to use the 210g hub

bm0p700f
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by bm0p700f

With either rim go with 28spokes. Go with the heavier rear hub and the light weight front. That's the better compromise.

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themidge
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by themidge

Sounds like a plan :D I'll probably build myself some carbon tubs in the future anyway, so reliable and still pretty light is enough for me right now.

Is 20 spokes on the front still all right? I might go for 24 anyway to keep the looks balanced, but it's an extra 18 grams worth of spokes...

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

by alcatraz

Straightpull spokes are bit more durable at the head. UL190 doesn't use them. On bitex I didn't catch the model number.

If you wan't to shave a couple of grams off those hubs try the dati r6. Triplet lacing is a bonus. However uncharted territory about the geometry of the build according to bm0p700f. I'd risk it because I like the feature package deal.

cx-ray's are nice but cn424 pillar1420 work ok and are cheap.

Nothching could be an issue.

For rims I'd like to try the new light chinese rims. I tried finding them on aliexpress but I don't have the patience to scroll through the results. :lol: Can you see the pictures and the specs here? Show this to some sellers and they can maybe get the rims. 390gr for 38mm ultralight version 28mm wide. Pretty good. High temp resin. :D
【公路碳刀 700C碳圈 超轻碳刀 T700 开口轮圈 38MM 50MM 管胎 DIY】http://m.tb.cn/h.3S1eG0c?sm=8404a0 点击链接,再选择浏览器咑閞;或復·制这段描述¥Rqpzb5hcZiP¥后到👉淘♂寳♀👈[来自超级会员的分享]

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