LittlePixel

I've noticed on small wheel bikes like with lightweight wheels like the Dahon Speed Pro and Bontrager-wheeled Trek F600 that they have half the normal spokes for lightness. If you had a normal 32h rim and just laced it with 16 would it still be a workable thing? I'm guessing 'yes' if the spokes could take the specific load - in my case 140Ibs of man and you filled the redundant spoke holes so they don't let grime into the rim.

Anyone got any ideas on this? Interested to try it as they look cooler and save a bit of weight....

smurfy

Check Sheldon Brown's website at sheldonbrown.com/harris

He built up a 18 spoke wheel from a 36h rim with mixed success. One of the rims had eighteen high spots!

ctp

I'm guessing 'n'o most of the time, since the rim with 32 holes has been designed so that each 1/32 of it bears a certain kind and amount of load. Then asking each segment to bear more load, with a nice big gap, wasn't in their original job description...in other words it very much depends on the design of the rim, and if it was overengineered.

It may look cool, but really how much weight do you think you will be saving?

LittlePixel

I'm talking about 20" wheels though which as far as I can tell need a direct hit from an A-10 before they go out of true. Thanks for your thoughts though. I might unlace an old wheel and see how it looks.

'nother

I think you could save more weight by taking a decent crap before heading out on a ride.

Just seems like a really, really bad idea, whether it is marginally functional or not.

phantomcow2

You sacrifice a great deal of strength and the weight is marginal.
Spokes are what, 4-7 grams a piece, depending on the spoke?
So you will save 100ish grams but sacrifice half your strength, not worth it.

rufvelo

1)I don't think 16 spokes on a 32 can be done. That is the wheel may be built to run true on the stand, but not ridden any distance without losing it's shape.

2)Just opinion, but I've never believed in less spokes - always ridden 32+ spoke wheels without problems. Maybe for top level competition, but generally not required for most applications and everyday use.

gorn

I think 16 spoke wheels look flaky anyway, but I was talking to this guy that sold me an old rear campy record laced to a tublar rim (for $10!) and he said that he has the front wheel somewhere too, but it's laced with just half the spokes with tape over the empty holes. He said racers used to do that to save weight, but he wouldn't trust it for city riding.

AndrewP

Its not the load on the spokes that is a problem but the concentration of load on the rim. The spokes on a small 16 hole rim are almost as close to each other as the spokes on a 700c 32 hole rim. The large rim with half the spokes will have a 'hop' between each pair of spokes.

DannoXYZ 

Yeah, you have to design the wheel as a whole with the number of spokes in mind. You need a rim that's stiffer so you don't end up with an S-shape snake of a rim that wobbles between spokes. The individual spokes on the 16h are also tensioned much higher than each spoke on the 32h for the same load-carrying capacity, almost twice as much. That's why they're big fat heavy-duty spokes on the 16h rims.

While your original idea will work, it will be a weak wheel. It will carry you around with no problems, but... it will be much, much closer to its limit than the 32h build. Hitting potholes, big bumps, bunny-hopping kerbs won't be as strong as with a wheel that's intentionally designed for 16h.

urbanknight

Wow, nobody mentioned that if you skip every other hole, one side will be too far forward and the other side too far back where they meet the hub. Remember the holes are offset for the number of holes they have, so if you skip every other one, the opposing side won't have holes exactly half way in between the other side. What that means is you would have to use really weird spoke tension to keep the wheel from truing sideways, this a very weak wheel that wants to twist sideways. No thanks.

caotropheus

Wouldn't be a more wise idea to make the front wheel with radial spoke patern?

LittlePixel

Thanks for all the info people. Reat assured I won't be doing it. I actually built my first ever wheel last night. I'm converting my sister's old Peugeot tourer into a fixie and am switching out the rusty steel 700c rims with some Mavics. There's a lovely zen-like quality to lacing the spokes. It probably needs a bit more tensioning but I was very pleasantly surprised that I managed to get it all pretty straight in less than a couple of hours...

Retro Grouch 

You have to engineer a bicycle wheel as a whole.

When you look at a minimum spoke 700c wheel, besides the scarcity of spokes the other thing that you will notice is a deep section rim. The deeper, stronger, heavier rim helps to make up for the lower spoke count. Paired spokes are also frequently used to counteract the tendency to pull the rim in a series of "S" curves from side to side.

urbanknight

Assuming you meant to keep it at 32 spokes but radial lace it for weight and aerodynamics, I would agree with you completely. A lot of people out there warn you not to radial lace, but it seems that it only becomes a problem if you are crashing (apparently, a radial laced spoke can pull right out of the hub under the forces of the crash. I have other things to worry about while crashing, and if I do I can probably save up for a new wheel while recovering. With that in mind, my velodrome and road bikes had radial fronts for all races (4x or 3x for training though) and I never had any problems. Not even needing to true them often.

freako

Not all wheels are designed for radial lacing, you have to ask your LBS or the wheel manufacture if radial lacing is recommended for that wheel, also not all hubs can be radial laced. But do not attempt to lace a wheel designed for 32 spokes with only 16 thinking your going to lose some weight and gain an edge, wheels are designed for a specific number of spokes and by modifying it beyond it's capabilities is asking for trouble. Also those fancy 16 spoke wheels you see on the road are high tension wheels and spokes, the 36 hole wheel you have is not designed for that, they are low tension and you will quickly run into a problem. You want a lighter wheel set try a 24 or 28 (better choice for durablity) hole rims and spoke them accordingly.

Retro Grouch 

That's not true. The tension required with radial laceing pulling right at the weakest point of the hub flange can cause the flanges to break out during ordinary rideing. It doesn't happen all of the time, but it happens often enough that Campy and Shimano won't warranty radially laced hubs.

MnHPVA Guy

This thread is hilarious, a bunch of people who've never done something, imagining reasons why it can't be done.

My friends and I have been doing this for 20 years without problems. 16 is plenty on a 20" wheel if the rim is even halfway stiff. I've even done 12 out of 36 on wheels that have lasted many years. The spokes do not have to be twice as tight, just tight enough that they don't go slack when at the bottom. In fact you will always get a longer lasting wheel with butted spokes as they can be stretched with less tension.

Radial is not a problem as each pair of webs is only supporting the tension from one spoke.

Skip pairs of holes in the rim, not every other hole. If you don't like the look of radial you can cross when using 16 of 32. https://bikesmithdesign.com/Paul/16x1wheel.jpg

Another trick for avoiding radial with 18 out of 36 is to use only the trailing spokes on one side and only the leading on the other. Might not work on the rear, though I don't know why, but will build long lasting front wheels.

urbanknight

While I have never built a wheel with 32h and 16 spokes myself, I have trued them and got to take a good hard look at them. First off, they seem to go out of true faster. Second, different spokes require different tension in order to get the rim straight. Now I haven't seen one that skips pairs of holes like you suggested, and that does make more sense since the spacing will be correct. I never thought about that one.

While I agree that it's a possibility, I have radial laced a number of wheels with no problems. I had a 32h Sun Mistral (box tubular) radial laced on my criterium wheels, and they survived the 1994 Claremont Criterium (deep rain gutters that cracked 2 carbon frames that day) without having to be trued. The reason radial lacing isn't all that bad on front wheels is because they don't see near as much torsional loads as the rear wheel which is being torqued by the drive side constantly. The flanges are quite strong compared to most rims today, which is why I think it's more frequent for a spoke to pull itself out of a rim. I have seen that happen, and spokes breaking at the nipple, but never have I had the chance to see a spoke pull through the hub flange, except in a magazine showing the damage from a Tour de France crash. But despite my long winded response, I do agree that it COULD happen.

freako

I did error on the problem with radial lacing lying with the wheel when it was indeed a more of a problem with the hub. I do not agree with radial lacing being used to make a reliable wheel; read this for more: https://www.sheldonbrown.com/wheelbuild.html

Ant then there's this from DT: Answer from DT:

The question about radial lacing comes up frequently. There are pros and cons of radial lacing depending on the component selection, rider, and use. There are only a few hard and fast rules about wheelbuilding. The fact is what works for some people will not work for others. At DT Swiss, we try to make recommendations that will benefit the majority of riders. Radial lacing looks cool. However, it places more stress on the hub, and in some cases, the rim. Most hub companies, like Shimano, DT Swiss, and Chris King, do not warranty standard hubs that are broken from radial lacing.
Some hubs are specifically designed for radial lacing. They are usually slightly heavier because the hub shell needs to be reinforced both in the flange area, and also around the bearings, to withstand the directly outward pulling of the spokes. Also in some cases the amount of flange material between the spoke hole and the edge of the flange needs to be increased. In the end, the weight savings of shorter spokes when radially laced may be less than the weight of the material added to the hub. As far as performance goes, someone your size will probably notice a handling improvement with a three-cross front wheel. The hub better supports the spokes, and there is a small bracing effect at the spoke crossings that stabilize the wheel.

Butted spokes will always be advantageous over straight-gauge spokes. They have greater elasticity and can handle the natural cycle of tension change that each spoke experiences as the wheel rolls. A three-cross front wheel with butted spokes and even tension is the way to go. DT Swiss now produces a tensiometer, which is a great tool for producing high quality wheels. You might ask your wheelbuilder if they are using a tensiometer.
Paul Aieta
General Manager, DT Swiss, Inc.

freako

I did error on the problem with radial lacing lying with the wheel when it was indeed a more of a problem with the hub. I do not agree with radial lacing being used to make a reliable wheel; read this for more: https://www.sheldonbrown.com/wheelbuild.html

Ant then there's this from DT: Answer from DT:

The question about radial lacing comes up frequently. There are pros and cons of radial lacing depending on the component selection, rider, and use. There are only a few hard and fast rules about wheelbuilding. The fact is what works for some people will not work for others. At DT Swiss, we try to make recommendations that will benefit the majority of riders. Radial lacing looks cool. However, it places more stress on the hub, and in some cases, the rim. Most hub companies, like Shimano, DT Swiss, and Chris King, do not warranty standard hubs that are broken from radial lacing.
Some hubs are specifically designed for radial lacing. They are usually slightly heavier because the hub shell needs to be reinforced both in the flange area, and also around the bearings, to withstand the directly outward pulling of the spokes. Also in some cases the amount of flange material between the spoke hole and the edge of the flange needs to be increased. In the end, the weight savings of shorter spokes when radially laced may be less than the weight of the material added to the hub. As far as performance goes, someone your size will probably notice a handling improvement with a three-cross front wheel. The hub better supports the spokes, and there is a small bracing effect at the spoke crossings that stabilize the wheel.

Butted spokes will always be advantageous over straight-gauge spokes. They have greater elasticity and can handle the natural cycle of tension change that each spoke experiences as the wheel rolls. A three-cross front wheel with butted spokes and even tension is the way to go. DT Swiss now produces a tensiometer, which is a great tool for producing high quality wheels. You might ask your wheelbuilder if they are using a tensiometer.
Paul Aieta
General Manager, DT Swiss, Inc.

urbanknight

That's some great info Freako! I always knew crossed wheels were stronger, but never thought about the pulling on the bearing. I still support radial lacing for lightweight racing wheels and time trial wheels, but as you pointed out, it's not good for high mileage or heavy riders.

LittlePixel

Thanks for all your info. I think the problem on this thread is that some people have missed the '20-inch 406 sized' thing and imagine I'm planning to do this to a pair of 700c wheels. 20" wheels are so bomb-proof; this is why I had the hunch I did - which you have confirmed. I look forward to lacing them - probably as 16 on the front when I pick up my rims next week. Did you seal the unused holes in any way? Is there any profit to be had doing that?

Nice one!
Huw

urbanknight

OMG I didn't even notice that you mentioned small wheels, let alone think that it could have been a 20". Oops. Anyway, you could find some plugs to go in the holes, but if you're using a velox rim strip or something like that, grim won't get inside the rim anyway.