Risk assessment -- radial laced wheels
 

I've got a pair of wheels that have high flange Campagnolo hubs laced to Fiamme tubular rims. Great, right? The trouble is, the front wheel is radially laced and the rear wheel is radially laced on the non-drive side. I've had them sitting in my garage for a few years, lacking the temerity to ride on them but also reluctant to give them up.

https://live.staticflickr.com/4661/2...9812d1d9_c.jpg

Now I find myself in the position of wanting to build a set of clincher wheels for my De Rosa. I have a set of high flange Record hubs in a box in the garage, but the rear hub is French threaded. So, I was thinking about how I could cheaply procure a high flange Record rear hub with English or Italian threading and I remembered the wheels described above. Hmmm....

This, finally, leads me to my question. Would you trust a hub that you knew had previously been radially laced to a rim?

I have no idea how much, if at all, it was ridden like that. The spoke tension is fairly low. The bike they were on was small, so probably the rider was light?

Just to add to the appeal of this thread, here's a pic of the bike the wheels were on, which has long since been passed on to @Andy Antipas

https://live.staticflickr.com/4748/2...bc4e5e6e_b.jpg

Andy,
I have a set of Campy hubs with the rear wheel built as half and half of 3X and radial spokes. No problems so far, and they are built on Matrix clinchers. I see no problems with them riding and have seen plenty of radial spoked wheels that performed quite nicely especially on front wheels. HTH, Smiles, MH

I've got two bikes with radially laced front wheels and one of them has a half radial rear wheel, yet here I am to tell the tale.

And get this for dicing with death; when I laced up the half radial wheel, the hub was previously laced up in a different configuration. Aaaaargh!

See, this is another aspect of the problem. The rear wheel on this especially is kind of a work of art with the funky drive side lacing to go with the radial nds. I kind of hate to tear it down. But (a) I really don't want another tubular wheel set, and (b) I'm a big guy and given the reputation these hubs have with radial lacing I'm not going to try it. So, the dilemma, destroy the work of art that is this wheel build or risk destroying the work of art that is the hub or find a new caretaker for these wheels?

:twitchy:

I thought that only applied to C-Rec sheriff star hubs?

I don't know. When I posted about this bike three years ago a bunch of people chimed in telling me that the wheels were going to explode.

Hmmm. Any hub can potentially fail with any spoke pattern, but I can't say I've ever seen a bias towards radially laced Campy high flange hubs. YMMV.

I have a pair of wheels never ridden with the front being radial laced. It is on a low flange Chorus hub. I too have been advised that the hub is not recommended to be radial laced due to the lack of material radial out from the spoke holes.
https://live.staticflickr.com/3854/1...bea386a_4k.jpgOmega Strada Hardox V Chorus Front 32_01 on Flickr
My plan is to re lace 3x just to be on the safe side. The analysis of the forces on the hub using a free body diagram while looking at the material affected makes me nervous. I am not going to do a FEA model but just use my gut instead. Better safe than sorry. Half radial in the rear makes sense to me due to the lower tension on the NDS. But again, I don't have a good feeling about it and without data, it is not a good informed risk.

Picked up the pair for $50. They were hung in a basement for 15 years before showing up on CL.

In the 1970s I experimented with radial spokes, front wheels only. I am absolutely not a fan because of the high stress caused by the direct radial tension. I did break a Shimano hub flange, and I blame radial spoking.

ditch the artistic spoking
go 3x and be happy
lets learn more about this frame set
intriguing fork crown.

I think it's really cool and you should keep it the way it is, particularly the rear wheel. It's not like you're touring on it or anything.

Also, are those drive side spokes tied and soldered?

It's a 1969 Urago, and apparently the cool chrome spear on the fork crown indicates it was built by Anicet Cattanéo. Unfortunately, it was much too small for me.

​​​​​​Yeah, they are. It's a very cool wheel build, showcasing the kinds of master wheel building techniques I've read about but never attempted.
The things is, and I know this will further besmirch my reputation around here, I really don't like tubulars. They ride great, but to me they aren't enough better than good clinchers to be worth the trouble and especially the anxiety (irrational though it may be) of going on a long ride with them. Basically, the reason I want clincher wheels for the De Rosa is that I think I'd ride it more often that way.

Were it my choice to make or problem to solve, I would disassemble the wheels, get some proper spokes and lace them up as 3x cross. Why take a chance with something (Campy high flange hubs) that is becoming more costly and harder to find? But that is just me.

Are the rims Ergal?

I think they're older than that. Also, I had forgotten that the front and rear rims don't match.

Front:

https://live.staticflickr.com/65535/...82e95d58_b.jpg

Rear:

https://live.staticflickr.com/65535/...37797408_b.jpg

So, yeah, whatever those are. Maybe a Super Champion Competition and a Fiamme Red?

The mismatched rims are another strike against the wheels as they are now in my book, though I do see that either rim by itself is pretty cool.

Rebuilding with a standard cross pattern might be risky. Back when Campagnolo offered a lifetime warranty on their components, they stipulated that hubs that showed evidence of having originally been built with one spoke pattern and then rebuilt with another (e.g., tensioning spokes rerouted to be pulling spokes) would not be covered under warranty.

I am not convinced there is a metallurgical justification for such a statement. Marketing and/or warranty positioning? Maybe. Document it and then you are covered. IIRC the reason you want to lace it the same way is to prevent spoke breakage as a result of deformed AL impinging on a spoke, causing a stress riser.

If true, then lacing it the first time would expose the spoke to the same stress - re-lacing a wheel in a different pattern results in the spoke elbow lying against a new portion of the spoke-hole chamfer, just as it does the first time it's laced.

Assuming there is a chamfer, of course, some manufacturers must be relying on the fact that spokes have a much higher yield point than aluminium (on the order of double or more); which fact leads me to suggest that one should worry more about the flange than the spoke. No doubt any of the marketing droids smart enough to know that would then put out such a warning; if it was the spokes breaking they could just shrug and say it was the spoke maker's fault.

It was at a seminar for local area bike dealers conducted by a Campy USA guy that I learned of the warranty exclusion for hubs showing two different spoke direction imprints. Didn't occur to me to question his point at the time (which was that such rebuilt hubs frequently crack or tear at the flange), but then I know nothing about metallurgy. Maybe someone such as cyccommute will chime in with some knowledge.

The Campy rep also said that the warranty was void for any wheels where the builder had committed the common blunder of miscounting the spoke holes (such that half the spokes appeared too short and the other half too long) but went ahead and finished tensioning the wheel anyway. "We're good," he said, "but even Campy can't drill an oval oil hole."

The bigger problem imo with radial lacing is the failure mode, where adjacent same-side spokes at the hub are also adjacent at the rim.

So in the case of a typical flange failure where perhaps two spokes suddenly lose tension, those two spokes are adjacent along the same side of the rim, causing the rim to go so far out of true as to possibly stop turning and possibly causing a crash or worse, a header. Spoke crossing prevents this by further separating spokes at the rim which are adjacent along the flange.

I've also seen quite a few radial-laced wheels fail while in storage, due entirely to aluminum's "creep yield" failure mode. Spokes don't fail this way but common aluminum alloys are known to yield slowly at the molecular level, similar to how plastics behave, even at "room" temperatures.
Today we have aluminum alloys processed to a degree as to be safely uses as spokes, in tension all of the time, but which doesn't apply universally to old hub shells.

Discussion about rim's role in failure or not. Would think a soft, weak rim would be a bad choice for radial spoking. On this rear, the radial is on the non-drive side which isn't tensioned as much as the drive side. Maybe good for time trials and riders who are light on the bike (versus gear mashers), but probably not for everyday use.

Andy, find another hub or wheel set, those are art wheels, probably suitable for a wall hanger or ride to the coffee shop bike.

Obviously the original owner had the drive side spokes soldered because it flexed too much, and I'm guessing they did radial on the one side to save a little weight. If I was wanting to ride those wheels I'd ditch the radial spokes. Just check the flange holes for cracks and you should be good to go.

your choice..... I ride both tubie and tubed and understand your concern...... for clincher tires I really like the conti gp5000 fwiw