# When hub and rim don't match... 36 or 32h hub... 20, 24, or 28h rim



## rruff (Feb 28, 2006)

Why even try it? You might have an old high holecount hub that is in fine shape that you'd like to lace to a lower hole-count rim. Or maybe you can get a great deal on 32 or 36h hubs, but not in the count you want your rim to be. Or you just want something that looks different than what everyone else has. I've been playing around with this lately and have come up with some patterns that look viable. 

The biggest downside is that you will end up with several different spoke lengths. You will also need to calculate those spoke lengths using first principals (like geometry), but it isn't that hard. You can get spokes from Alchemy (and probably some other places) in the exact numbers you need, so it isn't more expensive... unless you want to get a spare for every spoke length in your wheel. 

The strength of these configurations should be fine. They are all torsionally neutral on each flange. All the rim holes are used in each case. Some have a different number of spokes on each flange. Since this results in a few spots where DS spokes are paired together at the rim, a stiff rim must be used. If the number of spokes is the same on each flange, then you can use any rim you like.

I used a simple drawing program to make the layouts. The main thing you need is the ability to project a line at a specified angle... that way you can determine the intersect points for the holes in the flange circles and the rim.

If you see that I've made any goofs, please let me know! Questions and comments are welcome. If you think of any other configurations, then post them up...


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## rruff (Feb 28, 2006)

*36 hub, 28 rim*

The 36 hole hub seems the most versatile, because there is an odd number of holes per quadrant... this way you can center a pattern on one flange, and produce one on the other flange that is 90 deg out of phase with it. Both patterns below have 14 spokes on each side of the flange. To get the locations of the other spokes in the build, just shift the patterns 90 degrees 4 times.


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## rruff (Feb 28, 2006)

*36 hub, 24 rim*

This one looks kind of cool with 14 spokes on the DS and 10 on the NDS. This will make the NDS tension higher than normal and is a good choice for a hub that has a wide NDS spacing. You will need a fairly stiff rim for this build. Rotate each set 180 degrees to get the pattern for the rest of the wheel.


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## rruff (Feb 28, 2006)

*36 hub, 20 rim*

This is a simple design that will work well with any rim.


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## rruff (Feb 28, 2006)

*32 hub, 24 rim*

This is a 14-DS, 10-NDS that works with a 32h hub.


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## rruff (Feb 28, 2006)

*32 hub, 20 rim*

And here is one with 12 DS and 8 NDS.


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## Squidward (Dec 18, 2005)

I thought about building a wheel using a 24 hole rim and a 36 hole hub by lacing two spoke holes in the hub then skipping one. The way I was going to overcome the different spoke length issue was to calculate the different spoke lengths then, if I found two lengths that are close, buy the shorter one plus one or two millimeters and use a longer nipple for the longer spoke. This way I might end up buying two different spoke lengths instead of four. I've never actually built this, though.


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## rruff (Feb 28, 2006)

Longer nipples can work... but some of the 14mm nipples do not have longer threads. The 16mm nipples do. Another option is to use a Hozan spoke threader to add some threads to the longer spokes so they will work at a shorter length as well. Alchemy might do this for a fee if you buy the spokes from them.


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## Jetmugg (Sep 22, 2010)

I just found this thread after Zen pointed me to it. I'm noodling the possibility of using a 36H Sturmey Archer 3-speed hub and a 24H Sinz 24 x 1-1/8" BMX racing rim. One nice feature of the Sturmey Archer is that the hub flanges are symmetrical, so there is no dishing required.

I think I have it worked out using 2 out of every 3 holes on the hub (spoke, spoke, skip one), and a cross 2 pattern, which will mean that I only need to buy 2 different lengths of spokes.

Rruff - I saw your diagram showing a 36H hub and 24H rim example with 10 spokes on the ND side and 14 on the drive side. Since my Sturmey Archer isn't offset, would you still do the 14 and 10 trick, or would you go with 12 on each side?

SteveM - (PS - I'm an engineer, so the math part doesn't scare me).


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## rruff (Feb 28, 2006)

12 on a side for sure... don't unbalance the tension if you don't need to! Seems like that would be easy, but map it out and let us know how it looks.


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## Jetmugg (Sep 22, 2010)

Okay, here's what I've come up with. .. So far, I've just laid it out in 2D. I still need to add the 3rd dimension to figure the final spoke length(s). I'm calculating a 5mm difference in spoke length between the "longs" and the "shorts". At that level of difference, I think I probably need to order 2 sized, as opposed to splitting the difference. Would you agree with that, or would you use an intermediate length spoke so I'd only be ordering 1 size?

Keep in mind the diagram is only for 1 side of the wheel.

Keeping in mind that this is for a 7 year old girl, who weighs maybe 60 lbs, what guage spoke would you recommend? She will probably be able to ride this bike for 2-3 years, and I can't imagine her hitting 100 pounds by then.










Any advice is appreciated.

SteveM.


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## 11.4 (Mar 2, 2008)

Egad, you can tell it's turning into winter.


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## Jetmugg (Sep 22, 2010)

I calculate the two required spoke lengths to be 231 mm and 235 mm. Is that too much spread to "split the difference" and order 233's, or should I just order enough of each to have a few extras?

SteveM.


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## Zen Cyclery (Mar 10, 2009)

Jetmugg- I have tried to spread a gap such as that one and it will be much less of a pain to simply order the right sized spokes. You MAY be able to make it work, but you won't know for sure until your almost entirely done lacing the hoop.


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## rruff (Feb 28, 2006)

You definitely want 2 spoke lengths for that much difference. Also, check how the other side lines up. 

Spoke size for a 60lber? Anything will do...

BTW, you can order exactly the number of spokes you need from Alchemy.


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## Jetmugg (Sep 22, 2010)

Thanks Ruff. That's a very good point about how the other side lines up. I assumed that I would be able to "clock" the pattern on the other side so that it ended up needing the same spoke lengths. The rim will be centered between the flanges on this hub, so there won't be any dishing issues.

I don't know a good way to model the other side of the hub. The assumptions I have made are that the spoke holes on the other hub flange (they are both the same diameter) will fall in-between the spoke holes on the side I have modeled. Since I believe that to be true, would you agree that I can use the same spoke lengths as long as I am careful to start the pattern in the correct relative location?

I don't want to seem like I'm over-analyzing this, but on the other hand, I want to do it right the first time.

SteveM.


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## rruff (Feb 28, 2006)

Yes, the holes on the hub will be half way in between, but you have to consider that the holes at the rim will line up differently on each side. It might work out the same, but it's good to check.


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## Jetmugg (Sep 22, 2010)

Thanks again Ruff - it's nice to bounce ideas off someone with practical experience. I appreciate your feedback. 

I'd like to describe what I see, and please let me know if it raises any issues from your viewpoint...

The spoke holes in the hub on the opposite side will be halfway between the spoke hole locations on the side shown (thanks for confirming that). 

The remaining spoke holes in the rim will also be halfway between the spoke holes shown in the sketch I posted above. Unless I'm missing something, the same pattern should be possible, using the same spoke lengths, on the other side. The entire pattern will be rotated 15 degrees CCW or CW from the pattern shown.

Again, I've never laced a wheel in this manner before. I've built a handful of wheels, but never a mis-match of hub and rim. If there's anything I'm missing, I'd love to hear about it now, as opposed to part way through the lacing of the rim.

Steve M.


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## Mauro Brazil (Aug 17, 2010)

Huumm ... great to see this.
Think build my Record hubs 36/20 and 36/24 ...
I can use those spoke calculators since will be same spoke quanty per side?


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## rruff (Feb 28, 2006)

Jetmugg said:


> The entire pattern will be rotated 15 degrees CCW or CW from the pattern shown.


I'm not going to work it out because it's been awhile since I've looked at these, and they tend to give me a headache. But it sounds like you are thinking straight.


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## rruff (Feb 28, 2006)

Mauro Brazil said:


> Huumm ... great to see this.
> Think build my Record hubs 36/20 and 36/24 ...
> I can use those spoke calculators since will be same spoke quanty per side?


The Record hubs are good for a build that uses fewer spokes on the NDS, because they have a wide flange spacing.

It's best to go to first principals to calculate the spoke lengths... pretty basic geometry really. You need to figure out the angle between the hub hole and the rim hole, and then it's easy.


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## moern (Jan 10, 2014)

rruff said:


> And here is one with 12 DS and 8 NDS.




Hey-ho!
I'd love to have a look at your solution on this 32 hub, 20 rim idea, since I am actually trying to build such a wheel with a Sturmey & Archer S2C in a quite bike project. This hub is so heavy that I wanted to save some weight by reducing the number of spokes :
Well, I'm aware of the possible risks, but the hub seems quite massive.
But I can't see your "attached thumbnails"? Did you remove them?
Could you help me and make them visible here!?
Thanks a lot!
Moern


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## rruff (Feb 28, 2006)

RBR deleted all my uploaded images for some reason. 

Been a long time since I looked at this, but I think this thread will give you what you seek. Please reply either way. 

Help needed from wheelbuilders for 24 spokes on 36 hole hub. - Weight Weenies

You need a stiff (deep, heavy) center-drilled rim.


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## moern (Jan 10, 2014)

Hey rruff,
thanks for your reply! I've been digging deeply in that thread you recommended and grabbed a pencil and blank sheet. Finally I found a design, which seems -at least visually- viable. Four spokes are radial (two on either side). The spokes that go into the rim change the hub-side they come from one by one. Only the assignemnt of the hub-holes is irregular. One either side (16 holes and ten spokes): xoxoxxxoxoxoxxxo.
I'm gonna post a picture as soon as I have one, other humans can read. Greetings!


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## saybiz (Apr 12, 2014)

Thanks helps a lot


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## xaus27 (Feb 12, 2017)

hi i am unable to view the thumbnail. could you please help. really appreciate the help


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