smashndash

I’m having a new wheelset built and I have the option of going radial NDS or 2 cross NDS on the 24 spoke rear wheel. It’s rim brake.

My OEM rear wheel was also 24 spoke and radial NDS but the wheel was torsionally so flexy that the spokes would rub the rear derailleur and the only solution the shop could come up with was sticking an unnecessary spacer behind the cassette. I’m only about 135lbs/62kg but I was still able to flex that wheel without really trying too hard.

My new wheel is 24 spoke 2 cross NDS and is solid - but it also has a stiffer rim and uses cx ray spokes.

Does anyone run a radial NDS here, preferably on deep (56mm for me) carbon rims? Has anyone else had this experience with radial NDS spokes, or was that OEM wheel just garbage?

Andrew R Stewart 

I suspect the OEM wheel was laterally flexible, not so much torsionally so. Perhaps one of the draw backs to a minimally spokes wheel that has a lot of dish. Add in the reduction of clearances to fit more cogs and cage rub is more likely. As to the "unnecessary spacer", seems to me that it is necessary after all

I think you'll find that playing with lacing patterns has less to do with performance then spoke count, amount of dish and spoke tensions. Andy

ThermionicScott 

Have you read this yet? https://www.slowtwitch.com/Tech/Debu...ness_3449.html

smashndash

I mean... I did say that I have a very similar wheel - 24 spokes - that doesn’t have this issue. And I ride with a team of some very strong, large dudes (who have 40lbs on me and can destroy me on climbs) who all run 24 spokes. Though I don’t believe any of them run radial NDS.

I have read it, and it’s why I believe I was lacking torsional stiffness. I never had any brake rub despite throwing the bike around like crazy. The contact only happened when I was in the easiest cog. I could get the spokes to reach out to the derailleur even under a little power when seated, as long as I put down enough torque.

So does everyone here run 2 cross NDS? Anyone stronger and heavier than me (neither are high bars to clear) who have CX-Ray or similar spokes with radial NDS?

I wonder why Light Bicycle defaults to radial NDS then.

Bill Kapaun

Maybe the big guys spin a lower gear at a higher cadence instead of mashing like you?
With a low enough gear and a "jerky style", most anyone can torture a spoke.

smashndash

Doubt it. I climb between 90-120rpm when I’m going fast. And you’re right that jerkiness made it worse. But I want to be able to pedal how I please, especially since, again, I weigh 62kg and probably FTP around 220W.

Bill Kapaun

I smell someone that has their mind made up and is just looking for someone to agree to radial lacing.
It's not me.

smashndash

No... I’m actually against it as I know 2 cross will work. But I’m curious to see if anyone runs radial with no issues. It’s a racing wheelset so I want to build it up as “racy” as possible. Light Bicycle said they go radial by default (I didn’t state a preference one way or another). I wouldn’t have asked if they hadn’t said that.

ThermionicScott 

Obviously enough people use radial NDS without issue, that wheels of this kind stay in production. Wheelbuilders here on BikeForums tend to be a little conservative. You might get more experience and support for what you're trying to do, on a forum like Weight Weenies.

Litespud

Long time ago I had a wheel set comprising 32-spoke Mavic Open Pro rims on Chorus hubs, front laced radial with DT Revolutions (14g/17g, IIRC), and the rear laced 2x DS, radial NDS. One side had Revolutions, and the other 14g/15g butted spokes, but I can’t remember which was which. I had them built by Colorado Cyclist. Good solid wheels that lasted me years without needing anything (I was ~170lb at the time). I sold them when I bought my current Rolf wheelset - probably should have kept them as a climbing wheel set, as they were significantly lighted than the Rolfs.

smashndash

Thanks for your anecdote. 32 spokes is significantly more than 24 though, so I think I’d rather err towards 2 cross just to avoid the potential headache. Unless someone can testify to radial NDS being feasible with 24 spokes.

smashndash

I might make a weight weenies account to see if anyone there has experience with radial NDS. Thanks

ThermionicScott 

They have an "Everything Wheels" subforum featuring "The Wheelbuilding Thread" that has gone on to 400+ pages. Lots of good stuff to absorb. I just lurk on WW, since I already chat on too many online forums.

HillRider

Feasibility notwithstanding, what is the advantage of radial NDS lacing and why bother with it? The weight saving has to be insignificant. All I can think of is cool appearance.

Andrew R Stewart 

+10! Andy

surak

Did you ask Light Bicycle why they do radial NDS? Will they do 2X instead? I have pretty similar physical specs and have been thinking about the LB 56mm wheelset for a while now, still haven't decided though, but interested in your LB experience.

fietsbob

My only 24 spoke is on a 16" 349 rim rear laced 2 cross, both sides ..

but I don't follow the trendy builds that are now fashionable ..


seen: wheels built , spoked in groups of 3, 2 drive side to one to the left side ..

hub and rim made specific to that lacing pattern ..







...

Dan Burkhart 

I build a lot of 24 spoke rear wheels, and the only conditions under which I build radial on either side is if the hub takes straight pull spokes, in which case the spoke orientation is not optional, or the customer demands it for a J bend build.
I have also seen rims with farings that dictate spoke direction, so no choice there either.

ThermionicScott 

Since I can't see the wheel in question, are the drive-side spokes interlaced or not? Are we sure the derailleur and derailleur hanger are straight?

Jon T

With radial "lacing", the spokes are pulling on the weakest spot on the hub--straight out, where there is the least amount of parent material between the spoke hole and the edge of the flange. 2 or 3 cross puts the stress at an oblique to the flange hole and has lots more support and not as likely to rip out. Think about it for a minute and I think you'll see what I'm getting at. It's simple physics.
Jon

fietsbob

Not rear and not quite radial but does use straight pull spokes..
for Bromptons and other 16" folding bikes with a dynamo hub..

20 spoke... a 28, using a regularly drilled rim is also available..

WizardOfBoz

One site offers a condensation that lists some of the same things Andrew has. They condense a lot of sources and say
"Our goal is to maximize lateral stiffness, so how do you this? Well, in order of importance the contributing factors to lateral stiffness are*:

1. The rim stiffness
2. The number of spokes
3. The spoke bracing angle
4. The gauge of the spokes
5. The lacing pattern"

The say that that lateral stiffness is their key goal. I suspect that radial stiffness is gonna be somewhat related to lateral stiffness. Also, given your two stated options (radial and 2 cross), I don't think you have to worry about radial stiffness like you would if you laced 4 cross (tangential). Following the list above, you've got the stiffer rim in the new wheel. 24 spokes should be enough, especially given your weight. Spoke bracing angle is kind of fixed by the hubs and rims. CX-ray spokes are light - their cross-sectional area is about that of a 1.5mm diameter round section. And NOX composites suggests that lacing pattern doesn't affect lateral stiffness that much.

This leaves you to be concerned about tangential stiffness which is what you were complaining about I think. If you have a normal rear hub (that is not one that has a large, torsionally stiff center section) Jobst Brandt suggested that most of the driving torque will be absorbed by the DS of the hub. This would allow you to lace the NDS radially. The NOX folks use 2 cross and have done some research to prove it, but 3 cross gives you better tangential stiffness. I use 3 cross (and am rebuilding two vintage bikes using 4 cross), but I weigh 240 and the extra tangential stiffness is useful to me.

But all of this is the cart before the horse. What is it that you are attempting to achieve? If the big bugaboo is tangential flex, why not just use 3 (or perhaps 2) cross on both DS and NDS? What is it that you are looking for that the radial lacing offers that (for example) 2 cross doesn't? If more tangential stiffness is desired, why are you investigating lacing with LESS tangential stiffness? That is: