|   half-radial front disc wheel? | uber-stupid
Jan 7, 2004 12:55 PM | | I realize this question may earn me the nomination for the official captain crackhead of the freaky frankenstein society, but I'm curious if anyone's tried a half-radial lacing on a front disc wheel. I had a half-radial pattern on an old rear wheel, and the flanges on the XT disc hubs look beefy enough to handle a regular radial pattern if they weren't being used for disc brake purposes. So I'm curious, just for the sake of experiment, to know if anyone's tried this half-witted idea before.
And if I were to do such a foolish thing... how many crosses are recommended on the disc side? |
| Well isn't............. | Mike T.
Jan 7, 2004 1:08 PM | | .....experimentation how we learn and progress? I'm glad someone had the crackpot idea of putting pedals on a hobbyhorse's front wheel.
What about the rear wheel that had the radial spokes on the DRIVE side and the crossed spokes on the NON drive side? They therorized that it put the drive torque onto the lesser stressed spokes.
So why not give it a go Uber? What's the worst that can happen? The wheel starts to loosen up? I'm sure if you're smart enough to build a wheel you're smart enough to catch it before all hell breaks loose. |
| Well isn't............. | uber-stupid
Jan 7, 2004 1:32 PM | | That sounds like an interesting rear wheel... where'd you hear about that?
I'll probably give this thing a go, just for the sake of doing something different. Personally, it still eludes me how the spokes on two different sides of a hub can experience different torsional stresses, since the flanges are connected in the middle. Unless there's a serious amount of twist in the middle (which seems unlikely, or we'd hear a lot more about hubs that sheared in between the flanges) it just doesn't stand to reason that the spokes on one side would have to deal with more tension than the other. The hub, I can understand, would feel the difference on one side, but since it's a solid unit I don't see why the differing forces would move on to the spokes.
My own guess is that it's nice to have a certain number of crosses here and there, but that the wheel as a whole handles a certain amount of torque that's determined by a cumulative calculation involving both sides, regardless of which is laced which way... crosses on both sides of the wheel would feel the forces as transmitted through the full body of the hub. ...But then, what do I know. :)
I'll let you know if I manage to rip the hub in half. :P |
| I can't.............. | Mike T.
Jan 7, 2004 2:05 PM | | .....remember just what wheel it was but it was one of the pre-built boutique wheels and I think it was the one that had the carbon spokes a couple or three years ago. I'm sure someone will come up with the name.
People around here were saying the company had screwed up the spoking pattern but it turned out to be deliberate. |
| It is the Mavic road wheels | shiggy©®
Jan 7, 2004 10:54 PM | | Radial driveside, crossed nondrive. |
| I think mavic bolts their freehub to the nondrive flange though. | DeeEight
Jan 11, 2004 4:04 AM | | so the torque is mainly carried on the left side flange of the wheel, which is the cross laced one. |
| The pawls are still outboard of the right flange | shiggy©®
Jan 12, 2004 2:10 AM | | Mavic may have just beefed up the hub shell between the flanges (as compared to other road hubs).
Most mtb disc hubs should not have a problem transferring loads between the flanges. |
| Maybe contact this guy.. | Steve-O
Jan 7, 2004 2:53 PM | | http://www.stormpages.com/spokeanwheel/lacingcf.htm
He seems to be pretty big on crows foot lacing pattern and even shows a 32H modified crows foot pattern. Unfortunately he doesn't mention disk brakes on his page... |
| re: crow foot lacing wheel? | VernDog
Jan 7, 2004 8:25 PM | | I've built a few of the mentioned spoke patterns, just for shear novelty, not to prove that this is stronger then the tried and true 3 cross but just to have something different...Speaking of half radial half normal 3 cross lacing, look at some old Model T car rims from the early auto years, same mixed(half radial) spoke pattern and much more weight upon these wheels, I just finished a front hub, drilled like a motorbike front hub to build up a "racelace" spoke pattern...2 spoke circle diameters so all the spokes can be laced "heads out" I'll get a pic posted once I figure out how to do that on the forums section.
VernDog |
| Cane Creek sells one | shiggy©®
Jan 7, 2004 10:59 PM | | 28 spoke. Front is radial non-disc side.
http://canecreek.com/site/product/wheels/product/05_zonos_disc.html |
| I have built several mixed cross disc wheels | shiggy©®
Jan 7, 2004 11:08 PM | | 2-cross disc side and 3-cross non disc (32 spoke) and one 3x disc, 4x non-disc (36 spoke) front wheels. Used several different rims, all use Sapim Race 14-15 spokes and Deore disc or DT 240 disc hubs. Can not say I can tell any difference riding them. They all ride well and stay true.
I also built a geared rear disc wheel 1x drive side/3x disc side. Doing fine. It did need a minor truing after 4-5 rides under a 200-lb rider (not me). |
| OK, then... here's the next question regarding radial lacing | uber-stupid
Jan 8, 2004 2:12 PM | | On the radial side, heads in or out? I have a bonty non disc front wheel that had heads in, I have another wheel with a mavic D521 and specialized stout cartridge hub (non-disc) that has heads out. Are there any reasons in particular I should choose one way over the other in the context of a half-radial wheel? |
| Two schools of thought | shiggy©®
Jan 8, 2004 2:30 PM | | Heads out: Reduces the amount of dish on a "half radial" rear or disc wheel (when on the non-drive side rear or non-disc side front) . Reduces the amount of bend of the spokes at the hub flange. Some hub/fork combos lack clearance for heads in.
Heads in: On a non-disc and/or dishless wheel it increases the spokes' bracing angle for better lateral strength. The spokes are better supported by the hub flange.
Mostly builders preference. I like heads in for radial and 1x front wheels. |
| Two schools of thought | uber-stupid
Jan 8, 2004 3:18 PM | | maybe I'll alternate heads in and heads out :-p |
| Why???? Can't be for weight savings. | Cevan
Jan 9, 2004 8:29 AM | | Assuming you're using 14/15ga spokes, you'll save about .43 grams per spoke, or 7 grams for a half-radial wheel. |
| Why???? Can't be for weight savings. | uber-stupid
Jan 9, 2004 11:28 AM | | That's sorta why I said it would earn me the captain crackhead nomination.
To be honest, I don't really think it will perform significantly better, or worse, than a normal 3 cross wheel. I can understand why a full radial wheel is not good for disc wheels, but I don't think half-rad would really be that bad.
Partily, I suppose I would try to defend it by claiming that radial tensions are (I think) a little bit higher, so it might help balance the tensions on what is by nature a dished wheel. But basically, it's just something different, and something to do. If I get really bored I could even use black spokes on one side, silver spokes on the other, and alternate between all of the different anodized colors on the spoke nipples... but I doubt the madness will go that far. |
| Why? | seb at work
Jan 9, 2004 1:26 PM | | On a half radial wheel that is dished away from the radial side (which they typically are- drive side crossed or disc brake side corssed) the radial spokes are actually at a (slightly) lower build tension than tangential ones would be.
The main advantage to a half radial pattern is that with radial spokes, none of them can go slack under torque loads, so the (very slightly) lower tension never goes any lower under torque. This is actually a flaw if you need them transmitting the main torque load in thew wheel. However, it can be a useful feature on the "non drive" side of a dished wheel that needs to tranmit torque from the hub to rim.
An alternate solution is to reduce the dish, say through the use of an assymetric rim and "race lacing" one or both sides in the direction of the dish. That evens up the build tension on both sides, so neither one goes slack before the other, and thuis neither has an abnormal problem with spoke fatigue. |
| Why? | uber-stupid
Jan 9, 2004 10:00 PM | | I could be wrong about tension, but I wasn't thinking of it terms of tension under torsional loads, I'm thinking more in terms of lateral tension. The crossed side can (or shoudl be able to) handle the torsional loads, the radial side would be there to pretty much pull the rim simply away from the disc side. Since the dished side of a wheel is generally tighter, and radial patterns are known (or at least believed by some folks, from what I've read) to be more laterally stable, I figured the radial side would at least add lateral tension, and hopefully stabilize the wheel some that way.
By the way, please understand that most of this theorizing is coming straight out of my ass... it seems to make sense to me logically and theoretically, but not all of my theories have a solid grounding in practical application.
An offset rim might be a good idea, though, I hadn't thought of that. |
| You mean like this? | DeeEight
Jan 11, 2004 4:01 AM | | 32h laced 2x on the disc side and a spiral radial lace on the non-disc side (all heads in) with 14/15/14 butted competition black spokes and silver alloy nipples to a Diatech large-flange disc hub and a Sun SubIV rim. |
| Wow... maybe | uber-stupid
Jan 11, 2004 3:22 PM | | Why'd you spiral it in that particular direction? It seems to me that the spokes on that side wouldn't help at all under braking, that they'd all go slack... |
| Doesn't matter... the torque is carried by the left flange... | DeeEight
Jan 16, 2004 4:47 AM | | which is where the rotor is, not the right flange. |
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