2020: state of the spoke count theory?

[tylercheung]

As Fridays are given to idle speculation, I figured it was worth asking - what is the latest thinking on spokes? Esp the recent post about how 32 spoke hed and Easton rims are no longer available. What is considered “performant” or “standard” these days vs “heavy” and “overbuilt”?

Current assumptions:

Alloy 32h 3 cross: gold standard for road rims?

Carbon rims: stiffer, need less spokes?

New thinking - 28/28 vs 24/28 in alloy?

[adrien]

I'll weigh in on part of this.

Had 32s for years. I was around 260 when I started riding. Now about 215, but strong, with sprint ability to hit 1500 watts.

I've been riding Enve SES 4.5s for about 4 years. Radial front lacing and radial NDS rear, with 2x drive side. 20 front spokes, 24 rear. There's no weight rating on these wheels, and they've never been out of true. I did have them built up locally by folks who know their craft, but I also never thought such a low spoke count would behave this well under me. Besides this factor, I can feel that they are much, much stiffer laterally than anything else I've ridden.

Between a very stiff and deep rim and a relatively high flange (King hubs), the spokes are a lesser part of the system than older box rims. Local wheel builder said that the amount of tension they can hold is extremely high.

So FWIW, yes, I think carbon rims have stiffened matters such that, combined with their depth (because a shorter spoke is stronger) that fewer spokes are needed.

[Mark McM]

I think the idea that a particular usage needs a specific number of spokes (e.g. 200 lb. riders need at least 28 spokes) stems from the common idea that "wheels hang from their spokes". In reality, wheels don't hang from their top spokes, they compress inward at the bottom, and support loads by de-tensioning their bottom spokes (this is why spokes need to have high tensions - they can only help support the wheel as long as they don't fully de-tension).

Why does this matter? Because how much the wheel bends inward at the bottom depends on the stiffness of the rim, which is largely determined by its depth. Deeper rims simply need few spokes to support their loads. If we all rode around on 100mm deep rims, nobody would need more than 16 or so spokes. On the other hand, if we all rode around on 12mm deep rims, we'd need 32 or more spokes to make for reliable wheels. This is largely why we are using fewer spokes than we did in years past - our rims are deeper and stiffer than those old box section rims everybody used to use in the 1980s and earlier.

So, you can't just say 28/28 or 24/28 for alloy rims - it depends on how deep those alloy rims are. The original Campagnolo Shamal wheels from the 1990s with their 42mm deep alloy rims got by just fine with 16 spokes. Alloy rims closer to 30mm deep need a few more spokes, but 20/24 seems to work fine with these. If you go down to 20mm deep, then 24/28 or 28/32 might be better.

[Ralph]

It seems to me that all that has happened is that as aero properties got more attention or important.....rim design got bulkier......and heavier and stronger. So fewer spokes are needed.

In the past, most thought that rotating weight was the important thing, and that weight should be near the center of the wheel. That's not current thinking, as aero is now considered more important than weight. So we have these very aero designed rims which don't need many spokes.

I remember some of my wheels in the 70's. Record 36 hole hubs, 36 butted spokes on 280 gram box section flimsy tubular rims. I only weighed about 140, and still occasionally had wheel problems.

Now I ride on Campagnolo Zonda's mostly 16F and 21 R (14 drive side and 7 non drive side. high flange on drive side)....with rear deeper, wider, offset drilling, and stronger than front.....the rims look so durable I sometimes think the only purpose of the spokes is to attach the hub to the rim. And bikes are now faster (and more durable) with these low spoke count wheels. Much better wheels than I rode on in past.

Just my opinion!

[wallymann]

if you're looking at build-your-own alloy ersatz-aero profile rims like belgiums or archetypes, IMO 24/28 is plenty of everyday spokeage for most regular-job-having non-professional adult male cyclists. wee little dudes can go even lighter on the spokecount.

[carpediemracing]

+1 on lower spoke counts. There's a huge strength margin in today's much heavier rims.

In the old days you had 32H GP4s and if you were daring you might have gone 28H up front. The rim was about 400g. A "light" rim would be 340-350g (GL330 or maybe a FiR Isidis). A really light rim would be 300g (GEL280, FiR... I forget the Fir one, but it's narrow and light.. Alkor!).

Back then rims flexed. If you were out of the saddle the bottom half of the rim flexed. You'd get no brake rub because nothing flexed above the hub.

Nowadays a "light" rim is about 450g, like any of the standard Ardennes etc. With such a strong rim you can go quite low with spoke count up front. My Jets (faired rims so the rim itself is not 60 or 90mm tall) and Bastognes (aka Ardennes) are 18/24H, and my used and abused Bastognes are now over 10 years old. Maybe 8 or 9 flights, at least one 400 hour year, etc etc.

Carbon rims are lighter and stiffer, for a given height, and the tall carbon rims aren't much heavier than a "light" alum rim. They're so stiff they tilt around the hub, not flex below it, so you actually get brake rub.

I'm anywhere from 165 on a dream season to about 180-185, and pretty much the only thing I do is sprint. I'm a high torque sprinter, lower rpm, big gears, and I shift under 100% power. I'd like to think that I'm not that easy on equipment. In races I use road hazards (potholes, grates, etc) to move up since I feel okay riding through them and others don't. My 18/24 (carbon tubular) wheels have been fine for about 10 years of racing.

Prior to them I had 16/20 rims (Reynolds DV46s, both tubular and clinchers), for something like... 3 years? The front wheel was so rigid that I broke a spoke up front in a race, raced an hour with a 15 spoke front wheel (very gingerly, after riding at the back for a while so as not to take anyone else out) and ended up sprinting to about 6th? at the finish. On a 15 spoke wheel. https://www.youtube.com/watch?v=-lgRKWEdG18 (spoke breaks about 1:10 into the clip).

I broke a rear spoke on a group training ride, did 2.5 hours with the group, and no issues other than rubbing the brake.

[maslow]

Esp the recent post about how 32 spoke hed and Easton rims are no longer available.


Sorry to a PITA but can you post the link to this. Is it disc and rim brake models? I’ve searched on here but can’t find it. I had a pair of disc Belgium plus rims on back order from HED since end of 2019. Even bought the SON Delux thru axle hub and dt Swiss rear to build them up with.

Every time I’ve spoken to HED UK, last time of which was probably a couple of months back, I’ve been told they’re still awaiting stock.

Now slightly worried I might not be getting them.

[saab2000]

I use 28/24 on my Boyd Altamont Lite wheels (3 sets on different bikes) and they’ve been super solid. I could probably get by on 24/20 but at my weight, pushing close to 190-200 sadly, why bother saving a few grams at the cost of stiffness, strength and durability.

I have the impression that 32 would be total overkill and even more so for the front.

[tylercheung]

Sorry to a PITA but can you post the link to this. Is it disc and rim brake models? I’ve searched on here but can’t find it. I had a pair of disc Belgium plus rims on back order from HED since end of 2019. Even bought the SON Delux thru axle hub and dt Swiss rear to build them up with.

Every time I’ve spoken to HED UK, last time of which was probably a couple of months back, I’ve been told they’re still awaiting stock.

Now slightly worried I might not be getting them.

I think this was it: https://forums.thepaceline.net/showthread.php?t=252125

albeit I'm not sure how much of the supply problem are due to nefariousness vs. COVID supply problems...

[tylercheung]

I think the idea that a particular usage needs a specific number of spokes (e.g. 200 lb. riders need at least 28 spokes) stems from the common idea that "wheels hang from their spokes". In reality, wheels don't hang from their top spokes, they compress inward at the bottom, and support loads by de-tensioning their bottom spokes (this is why spokes need to have high tensions - they can only help support the wheel as long as they don't fully de-tension).

Why does this matter? Because how much the wheel bends inward at the bottom depends on the stiffness of the rim, which is largely determined by its depth. Deeper rims simply need few spokes to support their loads. If we all rode around on 100mm deep rims, nobody would need more than 16 or so spokes. On the other hand, if we all rode around on 12mm deep rims, we'd need 32 or more spokes to make for reliable wheels. This is largely why we are using fewer spokes than we did in years past - our rims are deeper and stiffer than those old box section rims everybody used to use in the 1980s and earlier.

So, you can't just say 28/28 or 24/28 for alloy rims - it depends on how deep those alloy rims are. The original Campagnolo Shamal wheels from the 1990s with their 42mm deep alloy rims got by just fine with 16 spokes. Alloy rims closer to 30mm deep need a few more spokes, but 20/24 seems to work fine with these. If you go down to 20mm deep, then 24/28 or 28/32 might be better.

I guess my asumption would be the recent "modern" alloy rims - i.e. belgium/+, archetypes, DT Swiss R460, Altamonts? These all seem to hover around 25 mm, it seems like.

Then again, who knows what will be "modern" in a few years?

[Mark McM]

I guess my asumption would be the recent "modern" alloy rims - i.e. belgium/+, archetypes, DT Swiss R460, Altamonts? These all seem to hover around 25 mm, it seems like.

For medium weight riders, 25mm deep aluminum rims in the 450 - 480 gram range (real weight, not advertised weight), 24/28 works well. Lighter riders might be able to get way with 20/24, and heavier riders might want to consider 28/32.

[jtbadge]

For medium weight riders, 25mm deep aluminum rims in the 450 - 480 gram range (real weight, not advertised weight), 24/28 works well. Lighter riders might be able to get way with 20/24, and heavier riders might want to consider 28/32.

Archetypes at 24/28 can handle plenty of weight. I've been riding my two sets configured as such since I was about 225 lbs. Never an issue.

[weisan]

I weigh 145...and I have no business riding the 32/32 wheels that I built, but I do.

:p

[tylercheung]

So what is the thinking behind 24/28 vs 28/28?

[Mark McM]

So what is the thinking behind 24/28 vs 28/28?

Rear wheels bear more weight, and they are dished (which decreases lateral stiffness and increases spoke tension differential), so they commonly use more spokes than do front wheels. If the front and rear wheels use the same rim and the same number of spokes, then either the front is slightly over-built, or the rear is slightly under-built.

[maslow]

I think this was it: https://forums.thepaceline.net/showthread.php?t=252125



albeit I'm not sure how much of the supply problem are due to nefariousness vs. COVID supply problems...



Many thanks

[marciero]

I'm fine with 32/32 on my single-bike handbuilts for my weight and the type of riding I do-distance/rando, bikepacking, camping-and the rims I use-alloy, ~ 20-25 mm depth. Yeah, hindsight I would probably go 32/28 if I had to do over with some of the fronts. I'm sure 28/24 would be fine but why push it. The camping bike with panniers on the front I dont see the point in going lower than 28, but 28 would be fine. When I started building wheels, in the absence of compelling reason to use less spokes, the fact that more spokes are easier to build was a consideration. Another thing is that with more spokes you can build up with very even tension, which can be difficult or impossible with fewer spokes if the rim is not perfect. There is also the argument about breaking spokes. You can easily correct a 32, or leave it slightly out of true, and ride as per usual. Cant do that with 20 spoke rear. It wont ruin an epic ride, like the guy I saw at one D2R2 who broke a spoke on a descent and blew out the tire within seconds from rubbing. But then, with 32 spoke wheel you dont have to worry about that because you will never break a spoke.

[oldpotatoe]

I use 28/24 on my Boyd Altamont Lite wheels (3 sets on different bikes) and they’ve been super solid. I could probably get by on 24/20 but at my weight, pushing close to 190-200 sadly, why bother saving a few grams at the cost of stiffness, strength and durability.

I have the impression that 32 would be total overkill and even more so for the front.

NOT saying that you should do this BUT 24/28 vs 32/32..that second wheelset is 3 OUNCES heavier than the first...'overkill'..as in those 84 grams are somehow a 'deal breaker' and that 'overkill' would actually mean something? I doubt, w/o counting the spokes, you would even know. BUT, all things being equal....more spokes=more reliable wheel.

BUT yes, carbon rims 'can' mean fewer spokes compared to 'some' aluminum rims but when designing a wheelset, there are so many variables, hard to say '32h is dead' or anything like that.
For medium weight riders, 25mm deep aluminum rims in the 450 - 480 gram range (real weight, not advertised weight), 24/28 works well. Lighter riders might be able to get way with 20/24, and heavier riders might want to consider 28/32.

What Mark said altho again, hard to etch anything in stone..too many variables. I mean, unless you are counting spokes at the coffee shop, probably wouldn't even know. BUT, break a wheel on an underbuilt wheel..you WILL know that.

"More races have been lost due to equipment than won, due to equipment"
-anan