Lacing 48-spoke rim/hub with 24 spokes

I just got a Nimbus X ISIS freestyle (the first 20" unicycle I’ve ever bought), and I’m really not happy with some of the design decisions. The axle spacers, which keep the wheel from spinning properly and violate the ISIS standard, I’ve gone over elsewhere, but one of the things I hadn’t realized before ordering it was that it’s a 48-spoke wheel. 48 spokes on a 20" freestyle unicycle makes no sense at all; it adds a bunch of weight, makes the wheel annoying to work with in terms of hanging it on a hook, using a pump, or using a spoke wrench, and given the poor quality of the machine wheel build, probably still doesn’t result in a particularly strong wheel.

20" wheels need fewer spokes than larger wheels to achieve equivalent strength. I’m considering taking the wheel apart and rebuilding it as a 24-spoke wheel, using 50% of the holes in the rim and hub.

My spatial relationships aren’t great, so I’m having a hard time visualizing how it will work before I take the thing apart. It seems to me that the current spokes, which are laced 4-cross, should be the correct length for a 24-spoke, 2-cross wheel. The rim holes probably won’t work out perfectly, because of the offset; what’s the best way to handle this?

I think it would be possible, and alot lighter. If you lace it with a 2-cross patern your spokes will be too long, you can probably lace it with a 4-cross patern again, or maybe 3-cross would be good. Someone else can probably answer better than me so I’ll let others answer…

P.S. I’m not a pro in english, that’s the reason why I’ll let others answer…

If I understand you correctly you are proposing to take out half of the spokes, every other one on each side, which will result in a two cross wheel. I think it will work, but I think you will have weaker wheel than if you get shorter spokes and rebuild as a two cross wheel.

As for the offset, you can use a hand drill and set the angle of the holes to the opposite direction to relieve the stress on the nipples.
I have drilled a rim this way just to play with having the spokes crossing at the rim. It made an interesting wheel, but probably no stronger than if I had laced it normally.

If you have a 48 hole hub you could get a 32 hole rim and rebuild it with that. You just skip every third hole in the hub. I’m not sure, but I think you could do it with a single spoke length.

48 spokes = nice for hockey - less likely to get ball-in-wheel / ball through wheel, and good for situations where people fall directly on the wheel, mostly hockey when I’ve seen it, but I hear freestylers do it often in some tricks, like fancy side ride / jumping on wheel type cleverness. Some freestyle type tricks also put lots of sideways stress on wheels, maybe more than most normal riding. I’ve seen more wheels damaged at hockey than on muni rides for sure.

I think you can just take out every other spoke, leaving it 2 cross - look it up on
http://www.unicycle.uk.com/SpokeCalc.asp

Although personally I’d just get a new spoke key that fits the wheel, and keep it as is.

Joe

You can’t just take out every other spoke, because half the spokes are inbound and half are outbound; taking out every other spoke would remove all the inbound (or all the outbound) ones, which sounds like it would weaken the wheel. (The hub would have less lateral stability).

Given a rim and hub of identical sizes, a 24-spoke wheel laced 2-cross will have the same spoke length as a 48-spoke wheel laced 4-cross. You have half as many spokes, therefore half as many spokes to cross for the same spoke line. (I checked this in a spoke length calculator).

Falling on the wheel is perhaps an issue; I don’t play much hockey, but would possibly play basketball on this uni.

Looking at the issue, it’s not possible to do perfectly. To space the spokes properly (using every second spoke hole), half of them would need to be offset to the wrong side (left-side spokes going into holes on the right side of the rim). Or, you could stagger the spokes (use two spoke holes, then skip two), which should work, but might result in odd truing behaviors.

I still might try it.

how about using 4 holes, skipping 4 holes? then you would be leaving out complete sets (1 set is 1 inside from each side, 1 outside from each side) so building will be easier and truing may be easier. I think the standard build is a 3-cross, so some spokes would be a one-cross and others a 2-cross. If you rebuild to a 2-cross you will probably find that the spokes are the wrong length (I had this with a 3-leading 3-trailing build). If you’re the gambling type, you could just do it by cutting the spokes!

This way may work, but you would probably have to re-tension and true the wheel regularly (which I’m sure is the case whatever you do).

Finally, it could look pretty good… let us know how it goes!

Interesting idea. I’d be concerned about the strength of the wheel in the gap sections; four spokes is a sizable area, even on a 48-spoke 20" wheel. It probably wouldn’t be possible to keep it round.

You’re weakening the wheel significantly anyway by using half the spokes and there are some road bike rims where the spokes are grouped closely and then a large gap to the next set…

And as long as you’re not over-tensioning the wheel it’ll stay round. it’s not like you’ll be using a rim brake…?

Lateral rim errors matter if you have a rim brake; vertical rim errors can be felt when riding. (thump thump thump thump thump).

ouch ouch ouch ouch ouch.
as long as the tension is not too high, it should be fine… I’d love to try it but I’ve not got the time at the moment and I don’t think my fiancee would be too happy as it’s her uni that I would attack (even though it is a 36-spoke)!

Did you go through with this? I haven’t really looked at this issue carefully, but whoever said removing alternate pairs of spokes sounds right.

BTW my mountain bike with 26-in wheels has 18 spoke wheels. Rim brakes too. I go off small drops, slam into rocks (at 20 plus mph) and curbs, all the usual abuse and they work fine. Thousands of miles. The only downsides that I can see to the spoke spacing is you can see the wear pattern on the rim—the rims obviously get shaped a bit by the spoke tension. The other is that sticks are more likely to get stuck in the spokes. This happens and can cause lock-up. Fortunately only the back wheel so far (since it’s usually the front wheel that kicks up the stick). As someone said on this thread or another, the only downside to few spokes on a uni would be putting your foot through the spokes when falling or doing stunts. I’m very much a solo beginner, so take the uni related stuff with a grain of salt.

26-in. mountain bike wheels are usually built with 32 spokes FWIW—downhill, freeride, whatever. 24 on a uni should be plenty. The weakness if any will be spokes pulling out of the rim or hub. And my guess would be that would only be an issue if you’re doing big drops.

I haven’t done it yet–I wound up having other issues with that uni and exchanged it. The replacement uni still has 48 spokes, so I’m still considering it when I get some time. I’ll probably buy a spoke driver first, just because de-lacing a 48-spoke wheel is really annoying.

I’ve just done it to a 24", 48 spoke wheel.
Removing spokes in groups of 4 at the rim looks great and leaves pairs of spokes together at the hub. It took less than an hour to do leisurely. Truing was easy too.
I’ve yet to see how it holds up, I’ve covered it with a disc either side as it’s going to be used for hockey.

It will be significantly weaker, I fully expect to have to rebuild it at some point (just hopefully not during a tournament). Someone’s got to do these experiments! :slight_smile:

A word of warning though - don’t do it to a 20" wheel purely to save weight - I saved just 180 grams so a 20" would save much less. If you want the looks do a 3-leading 3-trailing wheel build for the same strength.

I’ve just done it to a 24", 48 spoke wheel.
Removing spokes in groups of 4 at the rim looks great and leaves pairs of spokes together at the hub. It took less than an hour to do leisurely. Truing was easy too.
I’ve yet to see how it holds up, I’ve covered it with a disc either side as it’s going to be used for hockey.

It will be significantly weaker, I fully expect to have to rebuild it at some point (just hopefully not during a tournament). Someone’s got to do these experiments! :slight_smile:

A word of warning though - don’t do it to a 20" wheel purely to save weight - I saved just 180 grams so a 20" would save much less. If you want the looks do a 3-leading 3-trailing wheel build for the same strength.

Forget it.

Just had an uneasy game last night and in really tight turns you could feel the rim flex, almost like the Max Challenger! It became less noticeable but I’ll still be rebuliding the wheel shortly…

Like I said, someone’s got to try!

Do you think it would have worked better if you did a use 2 skip 2 pattern instead of 4 and 4?

possibly but I didn’t want to mess around with different spoke & nipple lengths in order to get a decent build.
The wheel is so much weaker I don’t think it’s worth the hassle or risk.