Radial Spoked Rear "Drive Side ???" Assistance Req

[Lazarus]

As per title above, I would love to hear from anyone especially wheel builders as to the pro's & con's of radially spoking the drive side of a 32hole wheel.

Question is = " Can drive side radial arrays be used safely ? "

The wheels are 32hole S/F rear Campagnolo Chorus Off Road Hub, DT Swiss DB Stainless steel spokes, on Mavic CXP12 rims (deep rim V). The CXP 12's are a solid rim that hold true on various build types, and are by and large "bombproof" rims.

I know that 2 cross & 3 cross are popular for their own reasons, but in general are used for lateral strength to prevent "drag" on the radial aspect when pressure is applied to the back block. I'm sure someone in here will know "from experience" why radial array is a No No OR a Yes Yes on this kind of rim / any rim.

I've used this array because I simply don't like the look of non drive radial mixed with a 2/3 cross drive side, used with a twin sided radial front. ie 3 sides radial - 1 side cross. So gents, any advice is welcome, yours Laz.

 

[dbmtb]

Re: Radial Spoked Rear "Drive Side ???" Assistance

As per title above, I would love to hear from anyone especially wheel builders as to the pro's & con's of radially spoking the drive side of a 32hole wheel.

Question is = " Can drive side radial arrays be used safely ? "

The wheels are 32hole S/F rear Campagnolo Chorus Off Road Hub, DT Swiss DB Stainless steel spokes, on Mavic CXP12 rims (deep rim V). The CXP 12's are a solid rim that hold true on various build types, and are by and large "bombproof" rims.

I know that 2 cross & 3 cross are popular for their own reasons, but in general are used for lateral strength to prevent "drag" on the radial aspect when pressure is applied to the back block. I'm sure someone in here will know "from experience" why radial array is a No No OR a Yes Yes on this kind of rim / any rim.

I've used this array because I simply don't like the look of non drive radial mixed with a 2/3 cross drive side, used with a twin sided radial front. ie 3 sides radial - 1 side cross. So gents, any advice is welcome, yours Laz.

The thinking is that there is more torque on the drive side, therefore it is better to have the cross as close as possible to the chain.

Also - the issue of wheel dish. It makes more sense with standard hub designs to have the higher tension at the side that is crossed so as to prevent the flange splitting at the spoke hole. As 8 speed and above designs have a considerable difference in tension on DS compared to NDS, it would make no sense to have the higher tension pulling on the weakest part of the hub flange, which is what would happen with radial spoking on DS.

With non-standard straight pull hub designs where the hub design reduces the wheel dish - it can be argued that it makes more sense to have the higher tension of the radial spokes on the drive side, to give a stiffer wheel - so Shimano and Spinergy (and others) have made wheels with radial DS spokes.

But don't do it with your Chorus hubs - you'll make the flanges split at the spoke holes.

It should be obvious why you can't run radial on both sides.

 

[Lazarus]

Hi DB Thanks for the info, it's pretty much what I expected to hear, but ... " I re-built a set of T Quattro Deep V rim 24hole radial wheels last year and changed the array from hit 1 miss 1, to hit 1 miss 2 hit 1, do you follow ?

ie: the wheels are 6 x 4h = 24h = 12 per side.
original spacing was : DS, NDS, DS, NDS.
new spacing became : DS, NDS, NDS, DS

Made for a much nicer looking wheel, put the higher strength on the DS, the lesser NDS. I bedded them in with no trouble after a 10mile test run and they held fine. A mild tweak after bedding them was all that was needed. That was 600miles ago and they are strong, steady reliable. In essence I broke the rules.

After making this change I wondered if perhaps Deep V rim's are stronger persay and require less "science / engineering" to keep them true and that perhaps old school rules were slightly outdated, hence that test. These Chorus Off Roads are seriously good strong hubs with thick flanges, and they are already built radially both front & rear. I'll assume your thoughts re: snapping the hubs is for when they are being ridden and put under some serious strain. This is why I wanted to post & ask to see if anyone has actually tried DS radial with good hubs on NON radial designed deep V rims.

Technically its possible because other wheels have them (my Roval's for example or the T Quattro's) . Don't get me wrong DB, I'm all ears on this 1 especially if what I'm listing to is from pro/expert/good wheel builders So my friend, that which might seem obvious has infact merely been put under the test of reality, the test being to see if anyone has tried this and knows from experience. The theory I agree with, but after making my T Quattro's the way I did and them NOT failing (trust me I've hammered them to try and make them break) I was game to try again.

More info please DB / anyone, yours Laz.

PS: I hear the below loud & clear DB, but I am no pro builder, just someone who listens a lot and has made his own wheels for years, without failure I guess I'm just getting experimental as I get older.

But don't do it with your Chorus hubs - you'll make the flanges split at the spoke holes.

It should be obvious why you can't run radial on both sides.

 

[Lazarus]

OK DB, had another read (there was much to digest)

Quote "Also - the issue of wheel dish. It makes more sense with standard hub designs to have the higher tension at the side that is crossed so as to prevent the flange splitting at the spoke hole."

If I understand this correct, you are saying that tension determines the dish ?

I have always built with = tension both sides with shorter spokes DS, the dish being determined by the spoke length. I've always used this method, 2 cross, 3 cross, radial.

Your wisdom would be appreciated by explaining further please Laz.

 

[dbmtb]

As I am sure you are aware, it is tension and only tension that determines the dish, as required spoke length is a pretty much a constant with only a couple of mm to go on for the given rim/hub/cross combination or you can't build the wheel if you want it centred.

Basically what I am trying to say is that to pull the rim over towards DS, requires more tension on that side. Quite a lot more tension. Radial spokes do not have the spoke they are crossed with to counteract that tension so all tension is placed on the hub flange. On NDS with less tension required, this is less of an issue than on DS. If you build the wheel with so little tension on the DS that you won't risk damage to the flanges, you'll have a very sloppy wheel that won't be very strong.

Seriously Laz - if there was a good reason to build a wheel the way you are suggesting, everyone would be doing it. But nobody is. There's a reason for that.

Of course if you are building wall-art then you can do whatever you want....

The flanges on Chorus hubs are pretty beefy. (I know them well and have built radial fronts and 3XDS/radial NDS with no problems. It's just he opposite that doesn't make sense.

 

[dbmtb]

I can see that what you mean is what is also referred to as crows footing.

So with some crossed spokes and some radials.

Well it will mean some variance in spoke tension which, all things being equal isn't good.

But your hubs will probably hold up as the deciding factor will be the tension at the crossed spokes.

Of course it's all about personal taste but I thnk it looks daft myself......

Fulcrum have it spot on with their 2;1 spoked rear wheels.

 

[Lazarus]

Thanks again DB "very informative and VERY helpful" Greatly appreciate you letting me pick your brains I've gotten away with the T Quattro build because of the hub/rim design, correct ? (made for radial DS), BUT, Chorus simply aren't designed to handle the stress loads, hence "looking good" but "potential death traps" when on the road (especially hill climbing).

You are gent & a scholar buddy, I now completely understand why the Chorus won't hold up. I shall change it accordingly I was placing too much emphasis on the appearance & strength of the rim to hold the wheel true, not realising the strength of the actual flange on the Chorus when put under so much spoke tension and drive tension when being ridden would most likely cause catasrophic failure of the flange itself .

PS: any tips for building 24hole Super Record Hubs onto CXP12 tub rims ? ie spoke pattern. I seem to have fallen in love with the CXP12's and want them everywhere. (unless you know of other reliable rims for 24hole SR) ie: Mavic Saturn tub rims ? Later buddy, Laz.

 

[dbmtb]

Super Record hubs won't work with high profile rims due to the position of the moon when they were made compared to the solar alignment of Pluto when the rims were made.

They only work with pre-1985 tubular rims unfortunately.

 

[monty dog]

There's a big wheel building thread over on Weightweenies - where radial or 1x on driveside is pretty popular on lightweight builds, particularly where there is a big dish and you fit heads-in to maximise the spoke angle. Mavic Ksyriums were the first wheels I saw with this pattern. I recently built a pair 28 Helium tubular rims radial DS/2x on NDS and they've survived a CX season.

 

[Lazarus]

Nah you lost me on the way to Pluto there DB, but thanks anyway Is the pre 1985 part real or part of the joke ? You take care buddy, yours Laz.

Thanks Monty Sometimes I like to delve a little into the unknown, and know from experience that often things not possible in the rule book, are often do-able in reality. The engineer in me is always seeking thresholds not boundaries Have realised since making this post that my Rovals are NOT complete radials DS, but stunning 1cross in a 16DS - 8NDS array. Had them for 18months, never used them in earnest, always loved them with their bladed spokes, yet never noticed the actual build.

Amazing wheels both visually and physically. So light, with strange hubs, instantly recognisable once you've owned a set. Thanks for the drop by buddy, yours Laz.