Sy Reene

If anyone would be so kind as to explain what makes a wheel strong. And I guess I'll define this by the weight limit that a wheel is rated to be able to support.

Some of the reason I ask, as while looking at various wheel options, there are a number of manufacturers who start at 20/24 but suggest 24/28 for over 180-240lb riders (Boyd). or over 175-215 lbs (November). Then on the other hand you have stock wheelsets (eg. Campy Zonda/Eurus or Fulcrum R3, etc..) with plenty of available reviews (are these valid?) indicating these wheels are bulletproof and supposedly ok up to over 220lbs... Yet they're constructed with a 16/21 spoke count, which is basically 2 steps down (20/24 inbetween) from 24/28?

What makes this possible? Is there a design choice difference between these 'camps' -- eg. stronger/heavier rims with fewer spokes, VS weaker/lighter rims with more spokes?

Carbonfiberboy 

Or the rim geometry may be different though weighing the same.

hueyhoolihan

pretty much. they probably use different rims, spokes, nipples, hubs. you name it...

Sy Reene

Maybe. It just seems a bit curious that most of the custom wheel builds (BHS, DCR) as well as the independent smaller size wheel companies seem to suggest 24/28 spoke wheels with Kinlin, Pacenti for anyone over approx. 175lbs. The stock name-brand wheel companies, Campy, Fulcrum, Vittoria (eg. Elusion) with 16/21 spoke counts, Zipp (eg. Zipp 30 which are actually 18/20) are all not too hesitant to suggest their wheels OK for up to 220 to 250 lbs. If not obvious this is mostly about the somewhat mid-tier alloy clinchers out there (ie. usually sub $700 for most of these, many under $500).

Sy Reene

Perhaps to simplify discussion and just take 2 different wheelsets and compare. Boyd Rouleur 2016 Rouleur Alloy Clincher - Boyd Cycling -- a 1550 gram wheelset for their 20/24 and 1606gm for 24/28, vs. Campagnolo Zonda https://www.wiggle.com/campagnolo-zon...7c5360518141us (1553 grams for 16/21 wheelset). The Boyds are 28mm height with 21mm external width. The Zondas are 26mm rim height in the Front, 30mm in the Rear; 20.5mm rim width.

Which would you consider the stronger wheelset? As a 185lb rider, am I deluding myself and swallowing the marketing speak that Fulcrum/Zipp/Campy put out there about their wheel weight capacity? Are the Kinlin/Pacenti/Boyd/November guidelines more appropos or are they all just working with a different set of materials' suppliers with different engineering philosophies?

colnago62

I am in the 240 lb. range at 11% body fat. I am a big guy. My experience has been that no wheel will collapse under from under me. What I have found that low spoke count wheels generally don't last as long as higher spoke count wheels, all other variables being the same. Deep dish rims allow for a stiffer wheel with less spokes compared to a standard box rim.

I have a set of wheels that I do a majority of my riding on; 32F, 36R. Durable and dependable. I have several sets of other wheels that I use for particular situations. For example, when going on a fast group ride in flat and rolling terrain, I might use my 808's. I probably put less than 1,500 miles on my 808's this year. They will last a lot of summers because I use the infrequently. For me, I have always had a pair of training wheels built for durability and lighter wheels that I used when the situation dictates the need for something else.

chaadster

Yeah, first off, the recommended limits aren't catastrophic failure points, but rather something else, most likely a random assessment of durability.

The reason for durability variation gets to matrials and design.

Look at the wheels from the small builders, and often you see narrow spokes and simple, traditional lacing patterns of j-bend spokes on standard hub flange spacings.

Compare that to the big wheel manufacturers, and you start seeing wide aero spokes of various materials (e.g. aluminum), often straight gauge, in proprietary hubs with wider flange spacings and differential fla ge heights, and smart lacing patterns which enable those low spoke counts. Some have other proprietary bits like nipples, or use off-center rear rims, to further give integrity.

Can you build a perfectly durable 3x spoke wheelset? Of couse. Can you build a perfectly durable low spoke count wheel? Clearly yes, but it's going to look different in terms of materials and construction technique.

Aubergine 

I just get 32 or 36 spoke hubs and rims, build 'em all up with good spokes, and don't worry about failure at all.

November Dave

This is a good question with a few answers.

I know that we (we being November) try quite hard to figure out what will work optimally for any given rider. We ride and test continuously (actually yesterday was the first ride I've taken since I don't know when where I had no notes to take or an agenda of things to observe), and we often enlist others to help us make judgments where we can't - different weight riders, etc. Plus we try to get a lot of feedback from customers to find out what's working or not for them. Boyd does a similar thing.

Weight is one big facet of the choice matrix, but there are many others. As we've grown (we grew a lot this year), the percentage of people contacting us prior to purchase has declined a little bit, but it's still REALLY high. Probably 40% of people who order at least confirm their selection with us prior to buying. In that interaction, we can ask a bunch of other questions which help us make our best recommendation. We're constantly working on an automated version of that process, with scores for various input, and maybe this winter we'll finally get it done.

We offer a broad array of lacing choices in alloy wheels - everything from 20/24 to 28/32 in rim brake wheels, and 24/24 to 32/32 in disc builds. It would be efficient from a purchasing and production standpoint to go one size fits all, but the product would suffer for it. But we do have a short supply chain - we generally buy from the company whose name is on the thing, and sell to you. For the bike industry, that's very short. If you take, for example, the Fulcrum Racing 3 (taken because it was mentioned in the OP and has a similar-ish price point to many of our alloy builds), for them to build with 4 different lacing options as we do would crush their supply chain. Campy would have to forecast lacing choice mix, make that into a production schedule, ship it to distributors, and then hope that retail demand ordered even vaguely resembled their forecast. That's really expensive on the way in, and if you get the mix wrong, it's really expensive on the other end, too. Shops would resist stocking multiple lacings of the same basic wheel, which would really hurt that supply chain paradigm.

We have zero interest in OEM business. OEM business demands one size fits all wheels. OEM business also demands a certain "shop floor attractive" look, which means low spoke counts. Someone will take exception to that but since "how few spokes can I get away with" is the question and exact phrasing we've been asked the most in our history, I defend that statement as an absolute truism. So we have the freedom to completely ignore those artificial aesthetic concerns. There will always be people who are turned off by our recommendations about how many spokes, and though I hate to sound callous about it, you can't please everyone. There are enough customers out there who get what we're trying to do, and it's with them that we build our business.

Looking again at the Fulcrum 3, it has a claimed weight of 1550g for clincher and 1565g for 2-way fit, with a 16/21 spoke count. That's the same weight as our Nimbus Ti build with Pacenti SL23v2 rims in 28/32 lacing. The 20/24 lacing of our build is right around 1450. People for whom the 20/24 build is appropriate get to do away with that weight, while people for whom 28/32 is appropriate get a benefit in strength, stiffness, and durability. Spokes are a great engineering tool for wheels. They add positives for bigger riders much more slowly than they introduce negatives. Much.

If our 28/32 build isn't at least on par with the Fulcrum 3 in aerodynamics, I will eat the computer on which I'm writing this response. Having put the 24h front of our build in a wind tunnel and having seen what Mavic wheels that have a similar rim shape and layout to the Fulcrums do in the wind tunnel, I have no fear of needing to eat a computer, and in fact am quite confident that it would be a solid win for our wheel. Drop down to 24 or 20h front wheel and it's going to go even further in our wheel's favor.

We have the flexibility to tailor the build to the rider, are free from external constraints like trying to make them look sexy on the shop floor, and we also really take a pounding if someone buys a set of wheels from us that they don't like or doesn't work well for them. It does happen, quite rarely fortunately, and it's pretty well my least favorite thing in the world so we try to avoid that.

Sy Reene

Thanks for the insights.. I guess I find reassuring as I'm considering after lots of hunting around, to just get a pair of Campy Zondas. While not as wide as my original target of 23mm rims, they're probably good enough, and the price (in the low $300s) seems great for the weight of this wheelset. Originally my hesitation was spoke count from this set (and others such as Fulcrum 3s etc..), convincing myself that a 21 spoked rear wheel was going to fail quite quickly.

Sy Reene

then again, this thread is interesting if you get to the last post in it.. https://www.bikeforums.net/road-cycli...-wheelset.html

Sy Reene

Thanks Dave. Your wheels are one of the first I've considered and am still considering. I'm a bit hesitant though going as wide as the V2 pacentis though as I have concern I can't fit my 25 tires in my current frame.

I might suggest in your case that at the price point, you'd be more correct to compare your wheels to Fulcrum R1s (or Campy Eurus) though, but your points are still well taken. I'm still curious though how well the factory wheels compare in strength to the more custom wheels such as yours. Would these 16/21 wheels be more or less strong than your 20/24 builds or your 24/28 builds?

chaadster

You're welcome, and I'm sorry I can't speak more deeply to how all the factors work together to inform wheel quality. One thing for sure, though, is that spoke count alone says NOTHING.

I ride four great wheelsets regularly on the road (ignoring my short haul, 'coffee shop' bikes, one of which is running stock, +40 year old wheels, and the other an '80s vintage wheelset): two Velocity-built wheelsets in 32 butted round J-bend spokes, a 20/20 straight pull aero-bladed spoke set from Mavic, and an 18/24 j-bend aero section spoked American Classic set. The youngest set is three years old. All have carried my 220lb, hard-charging butt across many miles of Michigan's notoriously poor roads, both paved and dirt, three have done crit racing, two crashed, and all have been launched off curbs and ridden in cold, salt-dust, and rain. All have been great.

My takeaway from that recent experience (I'll ignore the worst set of road wheels I ever had, which were 36 spoke straight gauge, back in the '90s) is that good wheels can be built in a number of ways, but having good design, the right parts, and quality assembly are where the real differences are.

Personally, I'd rather have a factory-built Mavic wheelset than gamble to save $100 bucks buying a wheel built up from common, off-the-shelf components by my LBS. No disrespect to that LBS, but I just think that wheel building has progressed far enough that I can assuredly get more out of the larger builders' wheels simply because of economy of scale in manufacturing and purchasing. That and, well, I wouldn't trust my LBS to slot my hubs for 3mm wide spokes...

November Dave

There are a lot of definitions of wheel strength. For this discussion I'll simplify it to the wheel's ability to resist coming out of true or suffering some other situation (spoke breakage, etc) which would require fixing.

The biggest drivers of wheel strength are hub flange separation, rim stiffness (both radially and laterally), rim depth (which is a huge factor in the rim's radial stiffness, but also has an influence on spoke bracing angle), spoke count, and spoke gauge.

Since information on the hub geometry of system wheels isn't readily available (and by readily, I mean I would have found it in the brief search I did), I can't compare that. Geometry info for T11 and Nimbus Ti hubs is here.

Quality of wheel build is paramount. In making any comparison, you have to make the assumption that each wheel is going to be able to be, and will be, built to a proper and very even spoke tension, round, and straight. The perfect components, built poorly, will be a crappy wheel. Lesser components built well will in general be a better wheel than better components built poorly.

The Fulcrum 5 has rims that are 23mm wide external, 17mm wide internal, and 24.5 and 27.5mm deep front and rear. A Pacenti SL23 is 26mm deep, 25mm wide, 20 internal. Based on overall wheel weights, we can assume that the Fulcrum's rims are heavier on average, which would give them some small advantage (shape matters more). The Fulcrums and a lot of similar wheels have highly reinforced spoke beds to deal with the high spoke tensions used in their construction. Version 1 of the Pacenti SL23 needed a little bit more spoke bed reinforcement, evidently, but version 2 (knock wood) has shown no deficiency in this respect. You could assume that the rims would be similar in their contribution to strength between the two wheels.

Spoke count, based on the research that we've done ourselves (parts of which can be read here, and also here) has a large impact on wheel strength. That is a very easy thing to compare, one set of wheels to another. In a similar way to how weight is probably over-considered as a standalone point, spoke count is over-considered in wheel comparisons because it is taken in isolation. The nature of the spoke/hub/rim interaction in a 50mm-ish carbon wheel is much different than it is in an aluminum rim half as deep. Errors in spoke count have different effects in one versus the other. But, since we've established that the rims are probably similar among the two wheel sets we're discussing at hand, and since 11 speed-compatible hub geometry can only get so good, and since WI's road hubs are proven to have good geometry, I'll make the assumption that the hubs used in Fulcrum 5s are equally as good. That puts us in a place where, spoke for spoke, the two wheels are basically equal in strength.

Then we get to spoke gauge. The only description given of the spokes used in Fulcrum Racing 5 is "stainless steel, aero, straight pull." Stainless and straight pull are easy enough to figure out, aero is a fun thing to call spokes. What does it mean? Even in this thread, there have been references to "aero spokes" where I'd bet quality money that the spokes in question net an aerodynamic penalty against round spoke alternatives. "Aero," until quantified in a wind tunnel, simply means "bladed." The spokes we use in the Nimbus builds are Sapim Laser in the front and non-drive, and D-Light in the drive side. The Fulcrum's spokes are probably heavier gauge. A small spoke-for-spoke advantage to the Fulcrum if that's true.

Taking all of that into consideration, I'd guess that our 1470g 20/28 build is roughly at par for "strength" with their 1658g 18/20 Racing 5. PLEASE NOTE that that doesn't mean that we would adopt the same rider weight recommendations as they give. We'll stand by ours with that.

We don't prefer to compare price point for price point. We prefer to use product level as a comparison.

garciawork

I have had two sets of Fulcrum Racing 3 2 way fit wheels (one left on a bike I sold). I can say that at my relatively light 160 (used to be in the 140's... need to ride more), over several years and thousands of miles the wheels are still completely true. About as bulletproof as I could ever expect. That said, I am not heavy, nor a powerhouse, nor very hard on them. So, I know they are pretty awesome wheels.

All that being said, if I needed a new wheelset, I would be strongly looking at the November's mentioned above. I love the hubs, and have heard great things about the Pacenti rims, and have also heard they run well tubeless.

JohnDThompson 

+1 this. If you race, then the low spoke count wheels make sense. If you want them to last forever, build with 32 or more spokes. Surprisingly, such wheels can be as light or lighter than low spoke count wheels, whose main advantage is aerodynamics, not weight.

fietsbob

Then there is Bracing angle , base of the triangle , spoke flange spread.. . rear wheels its narrow to get room for those 8,9,10+ cogs.

rpenmanparker 

Absolutely! There has never been even one single case where a 32 or 36 spoke wheel has suffered a broken spoke. Priceless!

Oh, I see the built in disclaimer. If you break a spoke on the 32 or 36 spoke wheel, it must not have been a "good" spoke.

I don't worry about failure of my 20/24 wheels at all either, but that has nothing to do with whether it will ever happen or not. It just doesn't matter a whole lot.

RJM

Well, when I have broken a spoke on a wheel with 32 or 36 spokes, I was able to ride back without the wheel going terribly out of true.

But, I currently roll on Rolf wheels, and thems don't have lots of spokes....I'm not too scared.

I also have a set of Novembers that have more spokes but are equally awesome.

Clipped_in

Nice post, and um can draft you?

Aubergine 

Now, now. My point was simply that I prefer to overbuild my wheels a bit. The extra weight of 8 or 12 spokes isn't worth fussing over, at least for me.

Wilfred Laurier

There are loads of 200+ pound cyclists riding low spoke count wheels, both shallow and deep section rims. My understanding of the weight limit on Campagnolo wheels is that the weak point is the hub design - not the rim or spokes.

rpenmanparker 

A reasonable approach!

Campag4life

Can you explain how your second to last paragraph is possible? What you write seems implausible.
thanks.
Also, if you can build a higher spoke count wheel with less weight than a low spoke Campy wheel, your rim is lower weight and with same modulus of elasticity is more flexible and weaker. No free lunch in engineering.
A last point is all I ride are factory Campy wheels and they have been flawless for many years. I am 175 lbs.

corrado33

Sheldon Brown thought that low spoke rims were a "scam" and that for most people, 32/36 or 28/36 (typical stock rim lacing) was fine.

Take that at what you will.