Bicycle Mechanics - 36 Spoke lacing: 3 cross vs 4 cross?

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rykoala
08-23-04, 02:38 PM
Subject says it. When inquiring to the LBS about a stronger wheel, they suggested a 36 spoke wheel laced 4 cross. This being for a 26" rear wheel. According to them the 4 cross pattern is stronger. Any word on this, wheelbuilders among us?
Rev.Chuck
08-23-04, 03:17 PM
Unless the hub flange is pretty big the spokes will make their first cross over the end of another spoke. This makes a high stress point( i have seen them break here) Three cross should be plenty strong.
karlfitt
08-23-04, 03:34 PM
According to the wheel building book I have, yes cross four is stronger.
I have never seen one laced this way so I can't responed to the above post about the stress point.
Gonzo Bob
08-23-04, 04:06 PM
My mountain bike wheels came 36 hole built cross 4. I don't recommend it. The spokes partially overlap the adjacent spoke head. In addition to weakening the overlapping spoke at this location, it also makes it really hard to remove a spoke when you break one.
A higher cross pattern for a given spoke count will make a wheel that's better at withstanding hub twist up forces but it will also be slightly weaker for side loads - i.e. may go out of true more.
rykoala
08-23-04, 04:26 PM
Hmmm OK. Where does a guy get a wheel that can handle high weight, and be super strong still? I don't want to have to worry about knocking a wheel out of true anymore...
AndrewP
08-23-04, 09:07 PM
Get a deep (30 mm) double walled rim. Have it built up with 36 14/15 butted spokes, as the thinner middle section will stretch more under shock loads, to give a more resilient wheel.
In the early 1970s, most European high-flange wheels were laced 3X, but the Japanese popularized 4X. (English 3-speeds traditionally had 32 spokes 3X, low flange, in front, and 40 spokes 4X, high flange, in back.)
On the front wheel, I doubt it makes any real difference, so I generally use 3X, which is slightly quicker to build. On the rear, 4X spokes are more nearly tangential to the hub flange than 3X, and are therefore theoretically subject to reduced windup/torque stress. Again, in practice, I am not convinced it makes any significant difference.
As to maximizing wheel strength-to-weight ratio, the more spokes, the better.
Hmmm OK. Where does a guy get a wheel that can handle high weight, and be super strong still? I don't want to have to worry about knocking a wheel out of true anymore...
An LBS with a wheel-builder who know what s/he is doing and talking about.
If you must have stonger wheels, perhaps you could find some tandem 40 or 48 spoke rim/hub combos.
A 36/cross 3 wheel is pretty damn strong. I think much of that strength is compromised with modern 8+ gear clusters, when the wheel is dished so much.
I wonder if there are high end options for 12g spokes, like I've seen on some heavy duty Worksman bikes?
rykoala
08-23-04, 10:35 PM
So is this an argument for a purpose built single speed wheel, with a bmx freewheel?
So is this an argument for a purpose built single speed wheel, with a bmx freewheel? Regarding wheel strength: 1) The more spokes, the better. 2) The less dish offset/asymmetry, the better. The latter is why mountain bikes tend to have wider rear triangles than road bikes, for a given number of cogs. If you need maximum strength on a road wheel, without giving up your gears, consider custom-spacing and custom-dishing with, say, a 7-speed freewheel/freehub on a 130 or 135mm overlock axle, assuming your frame can safely handle the spacing. (Just be sure to tighten your low gear limit screw far enough to keep your rear derailleur and/or chain out of your spokes!)
It would be better to do 4X with a disc hub due to it's larger flange, thereby mitigating the potential stress point. Having said that my 32 spoke Rhynolites laced up three cross have been just fine for this Clydesdale.
P. B. Walker
08-24-04, 02:07 PM
I had a 4 cross road bike wheel and had nothing but trouble with it. Spokes were always coming loose or breaking. I was in the LBS every weekend to get the wheel fixed or spokes tightened. I went to another wheel builder who stated emphatically that I should have never gone with a 4 cross pattern. He then built me a set with 36 spokes and 3 cross pattern and they've been perfect for 7K+ miles. And I'm a clydesdale for sure, ~275lbs.
I agree with something one of the other posters stated, if you don't think a 36 hole, 3 cross pattern will work for you, then go with a 40h or 48h wheel. But with a mountain bike, a 36 h, 3 cross wheel should work. You might also look into finding a deep V rim so that the spokes are shorter.
Rev.Chuck
08-24-04, 07:44 PM
I have built several trials wheels, 32-3x, with never a problem. My first trials wheel, with ten years on it, shows no issues other than starting to break its alloy nipples at about eight years(since replaced with brass, still original spokes)
Hey, Rev. Chuck, is 4X even possible on most 32-hole hubs?
I currently run 32/3x on the Bianchi and 36/3x on everything else, with no complaints or problems.
Hey, Rev. Chuck, is 4X even possible on most 32-hole hubs?
.No It's not divisible by nine.
No It's not divisible by nine. Neither is 40, but 40-4X was standard on the old English 3-speeds. Prime factorization of spoke count is irrelevant here, but the lower the total spoke count, the less radial the spokes become, for a given cross-number and hub flange diameter.
brucejackson
08-25-04, 03:22 PM
I don't think the previous poster meant divisible by 9. What he meant to say was the maximum number of crosses for a certain spoke count wheel is determined by the floor of dividing the number of spokes by 9.
48/9 5
40/9 4
36/9 4
32/9 3
28/9 3
24/9 2
etc.
With the right hub there is nothing wrong with 4 cross. If the flange is two small the spoke will travel over the head of the adjacent spoke. As mentioned this makes it harder to lace and can cause fatigue. Most of the Japaneese sport touring bikes I sold in the 1980's had 4x rear and 3x front wheels. Most rear hub flanges are large enough to avoid overlap while most fronts aren't. Certain brands of hubs make the front flange the same size as the rear (e.g. Bullseye, Specialized sealed bearing hubs, Phil Wood). With these hubs you can build the front 4x with no issues and in fact I normally did.
I do remember that you can go too large on the flange for 4x. I know Jobst Brandt cautioned against lacing drum brake and large flange hubs 4x. I don't remember the explination but I do remember him saying it wasn't good. Before I knew better I did build several 4x large flange wheels and I didn't notice any problems with them.
Retro Grouch
08-25-04, 03:59 PM
I've built some hub brake wheels that had some really big hub flanges. When you try to cross too many spokes, the spokes seem to approach the rim at too much of an angle and eventually break at the nipple. I also rebuilt a rear internal hub geared wheel from a Bike Friday triple that had been replaced by Bike Friday once and rebuilt once by another wheel builder. It looked to me like it suffered from a similar problem due this time to the 20" wheels. I smoothed out the divots in the rim flange spoke holes with a dremel and relaced the hub cross 2 and, last I heard, hasn't broken a spoke since.
I don't think the previous poster meant divisible by 9. What he meant to say was the maximum number of crosses for a certain spoke count wheel is determined by the floor of dividing the number of spokes by 9.
48/9 5
40/9 4
36/9 4
32/9 3
28/9 3
24/9 2
etc.
With the right hub there is nothing wrong with 4 cross. If the flange is two small the spoke will travel over the head of the adjacent spoke. As mentioned this makes it harder to lace and can cause fatigue. Most of the Japaneese sport touring bikes I sold in the 1980's had 4x rear and 3x front wheels. Most rear hub flanges are large enough to avoid overlap while most fronts aren't. Certain brands of hubs make the front flange the same size as the rear (e.g. Bullseye, Specialized sealed bearing hubs, Phil Wood). With these hubs you can build the front 4x with no issues and in fact I normally did.
I do remember that you can go too large on the flange for 4x. I know Jobst Brandt cautioned against lacing drum brake and large flange hubs 4x. I don't remember the explination but I do remember him saying it wasn't good. Before I knew better I did build several 4x large flange wheels and I didn't notice any problems with them.That's the point I was tying to make. :D
i8angus
09-30-04, 06:27 AM
Hello all,
I am building an electric bike and the 20" rear wheel will be subjected to lots of torque. I have a Surly 36 hole single speed disk hub and had planed on lacing 14G spokes to a bmx rim 4 cross.
After reading your posts I am wondering if I would be better to use a 12G spoke (if I can get them) and lace them in the 3 cross pattern.
Any advice you guys can give me :o ?
Thanks
Subject says it. When inquiring to the LBS about a stronger wheel, they suggested a 36 spoke wheel laced 4 cross. This being for a 26" rear wheel. According to them the 4 cross pattern is stronger. Any word on this, wheelbuilders among us?
Hi
Go for 3x double-butted. They will be more than strong enough if tensioned properly,evenly and stress- relieved. Use 4x only for hubs with large flange hubs. Using 4x with small-flanged hubs means every spoke would tend to lie on the head of the adjacent spoke. Choose your wheelbulder with care!
legalize_it
09-30-04, 05:41 PM
rykoala-
what rear hub are you using? hi or lo flange?
I don't think the previous poster meant divisible by 9. What he meant to say was the maximum number of crosses for a certain spoke count wheel is determined by the floor of dividing the number of spokes by 9.
48/9 5
40/9 4
36/9 4
32/9 3
28/9 3
24/9 2
etc. ...
Thanks for the clarification. Although I have built numerous 0X, 2X, 3X (my favourite by far), and 4X wheels over the years and have read several articles and postings on wheel building, I have to admit I have never before seen your equation, which does look like a very rational (so to speak) guideline.
rykoala
10-01-04, 08:30 AM
Well I am pretty shocked by the number of responses, and that this thread still lives! Its great info that has come of it. I ended up buying a new wheelset last night. Deore LX hubs on Mavic double wall rims, cant remember the model number. But, I plan on taking the bent wheel from my bike and re-using the hub (older XTR) to build my own wheel for the first time. So this info is VERY valuable to me.
dirtyscratches
10-04-04, 11:34 AM
Just to throw it in the mix, how about crow's foot lacing? Check out this page on it:
http://www.stormpages.com/spokeanwheel/lacingcf.htm
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