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32 or 36 spokes - Does it really matter?(19 posts)

32 or 36 spokes - Does it really matter?zmarke
Mar 11, 2003 9:47 AM
I have heard arguments for both:
32 spokes - less weight and wind resistance.
36 spokes - needs less tension which can mean less broken spokes and stronger wheels since the flanges of the hub do not need to be as strong.

My road bike has 32 spokes that always need to be trued. Could this be my weight or I am just not careful enough about the potholes and other road hazards?

I am building a fixed/single speed bike for winter training and commuting around the mean streets of NYC and need real world experiences and your strongest opinions.

I should mention that depending on what time of year it is I am between 190-200 pounds.

thanks in advance.
from what I have read...PeterRider
Mar 11, 2003 10:20 AM
don't remember if it was on Sheldon Brown's website or in the Jobst Brandt book: a few years ago, it was better to have 36 spokes for a strong wheel, but now pretty much any 32h setup is fine for any rider below 250 lb. Just because the quality of the components lines has improved.

It depends also on your rims. I've tried the CXP 33 that were staying true even when I jumped curbs and tried the bumps like on a mountain bike (conclusion: a road bike is not nice at all for jumps - is it due to the frame geometry, the larger wheels ? ). Now I have velocity aeroheads which I have to true relatively often. Since I did the build myself for both sets I know that the quality of the build was similar. I still jump curbs and go into potholes, just true the wheels more often.

Pierre
Less tension = more broken spokes.MR_GRUMPY
Mar 11, 2003 11:10 AM
A 36 hole wheel with DB spokes should las a very long time.
My experienceburdiman
Mar 11, 2003 12:26 PM
I am a certified wrencher but haven't worked in a shop for over 10 years. Anyway I weigh in around 225 (6'7") and build my own wheels and most of my friend's wheels (with a tensiometer).

Ok, anyway you can go 32 but I prefer and build all of my rear wheels with 36 spokes at around 125kgf (drive side).
If you use DA or Ultegra hubs use spoke washers between the head and the hub flange. That should help reduce breakage occurring at the elbow.

I am a big advocate on 36 hole wheels. Heck pick up 4 spokes there isn't much weight there (I know is it rotating weight but hey).

If you are using these to commute I would definitely go with 36 spokes. If you want aerodynamics tape your ears to your head or tuck in your elbows.
My experiencerussw19
Mar 11, 2003 3:19 PM
I have read (and I really wish I could find it again) an article that states that 32 spokes are actually stronger due to the wheel being more symetrical. The weak point of wheels has always been the J bend of the spokes, but the next weakest point is the hub flange. Most modern hubs are pretty damn strong and that shouldn't be an issue anymore. So that leaves the J bend. The article I read stated that a 3 cross lacing pattern with a 32 spoke wheel puts less stress on the j bend than a 3 cross pattern with 36 spokes and the spokes distribute the stress better as the pattern is more uniform and there are less holes drilled in the rim. But I can not find that article so I really can not back it's statement up either. I am not looking to start a flame war in this thread, but has anyone else heard this theory?

Regardless I would recommend a really good strong rim and hub combo as your solution, no matter if you choose 32 or 36 spokes. The strongest rim you can buy for road bikes without getting an overly heavy rim is the Mavic MA3. It's a simple box section rim, but makes a nice cyclecross/touring rim and is stronger than the CPX33, but weighs the same. Check those out, that's what I use as my commuter rims on my town bike. I beat the crap out of those wheels and I have never had problems with them.

Russ
The "triumph" of hair brained theory over realityKerry
Mar 11, 2003 5:51 PM
Sure, you can make an argument on paper (not based on physics or science) that 32 is stonger than 36 due to "symmetry" or whatever. Same argument for copper bracelets and pyramid crystals. However, there is no rational way to support that claim, as anyone who has passed Statics and/or Dynamics courses could tell you easily. There is no question about it, at comparable build and component quality, more spokes makes for a stronger and more durable wheel. Whether you need the extra strength and durability is the question, but it is there for sure. Full stop.
The "theory" I heard was that the hub flanges were stronger.dzrider
Mar 13, 2003 5:59 AM
The decreased number of holes when they went from 36 down to 32 allegedly left more metal on the hub. Whether that is a meaningful improvement is anybody's guess. Suffices to say, at 175 - 195 pounds, I've not been able to notice a difference in durability between 32 and 36 hole wheels.
Yikes!! and to the original poster, too.sprockets2
Mar 12, 2003 9:54 AM
There are a couple of things here that seem funny to me. I wish I could read that thing, I have never heard that arguement. I must agree with Kerry on this one-all else being equal, the 36° wheel will be stronger in every regard THAT ACTUALLY MATTERS.

The hub thing may have been true in the Golden Age, and may be true to some extent if you are talking about radial lacing on some hubs, but with 3x it ain't gonna matter-the hubs are gonna be strong enough. The critical thing is energy absorbance in the spoke structure and more is gooder. Obviously, there are practical limits on strength gains as you add spokes, but at 36° wheels, you are not at that limit yet.

If the MA3 is about the same weight as the CXP33, I don't see how the MA3 can be stronger-it isn't made of the stronger alloy that the CXP33 is. What do you mean by stronger anyway? I ran MA3 for years and liked them, but I never would have called them "strong". I am perplexed. Explicate yourself please.

To the original poster: only you can know if you need a super-duty wheel or not, based on your style and terrain. You might want to go with a heavier rim if you feel that you need the strength. A Velocity DeepV rim would provide awesome strength for its weight if you need that much. A guy I know who runs a bike shop built a 36° Deep V wheelset for his Tandem bike and says they are excellent in that application.

If you are having true problems now, you might be beating the crap out of the wheels and/or they may not be the best built wheels ever.
Agree and disagree.....DaveLobster
Mar 12, 2003 10:55 AM
The basic premise of 32 being stronger than 36 spokes, when both are laced 3x is that the 32 spoke wheel has the spokes closer to being at a tangent (ie: 90 degrees off radial). Hold a wheel with the valve stem at 12 o'clock. Trace the two almost parallel spokes by the valve stem down to the hub. On the 32 hole, they will get closer to 3 and 9 o'clock than on a 36 hole. I agree that it is so theoretical as to not give any real-world benefit, and you are better off with more spokes.

However, you are forgetting that the MA3's are triple-cavity rims. What they have is internal reinforcing that goes between the inner and outer walls of the rim (breaking the internal part of the rim into 3 sections). Compare a cross-section of an MA3 to an Open-Pro and you'll see what I mean. This internal reinforcement gives the rim extra strength, both laterally and vertically. This is internal and hidden, but does as much or more for strength as having a deep V section. -Dave
Agree and disagree.....russw19
Mar 12, 2003 4:57 PM
I didn't jump back into this one right away on purpose. As I stated in the first post about this theory, I am not looking to start a flame war over it. If you can show me proof not allegory that one design is better than the other, I would consider myself enlightened, and not offended. And two, this is a theory I have heard, not particularly one I hold, and I only asked if someone else had heard of it.

Here's some wheel facts... I am sure we all can agree on these...
First, there are VERY FEW people in the world who fully understand all the precise forces that affect a bicycle wheel. There was no science involved in getting to a 36 hole wheel being stronger than a 32 hole wheel. It was trial and error. Period. Nobody ever did any calculations in the 50's to determine if 36 holes was indeed ideal. There were no models to test the math of 36 hole wheels as the optimum. It just so happens that for many many years people built 36 hole wheels and they were strong, so the idea is that 36 holes are strong. That's as scientific as it gets... if you don't believe me, ask Jobst Brandt about this. Now, is it at all possible that they overshot the optimum by 4 spokes? Sure it is. But has anyone proven one way or the other? No.

Again, I don't want to break this thread down to a flame fest.. if you have an idea, share it, if you think someone is wrong but can not prove it, then save it for a different thread, as that's not what I am looking for here. Of course I don't own the board, so if you want to tell me I am a quack, oh well, I can't stop it.

Now here's the meat of the research I was referencing and it was a few years old and before Campy Shamal 12 spoke wheels, which obviously prove that 36 may not be necessary, but may still be stronger. The point was that the weakest part of any spoke is the J bend. When you build a wheel you try as hard as possible to seat the spoke perfectly into the hub flange so as to eliminate stress from the spoke's bend, but that never happens in the real world. There is always stress there if you build by hand. That is the one place where machine built wheels have an advantage. They can preload the spoke to force it to fit the hub hole better. -Reference is Jobst Brandt's "The Bicycle Wheel" and many of his articles on wheelbuilding. The article I was referring to claims that due to the angle of the spokes in a 36 hole wheel compared to a 32 spoke wheel the stress at the spoke's J bend is slightly less in the 32 spoke wheels due to the symmetry of the build and therefore the wheels are slightly stronger, all other factors being the same. Can I prove it, nope. That would make a great thesis for a Physics Grad Student, but above my head and I don't have the lab to test it anyways. Point is, neither does anyone else here.. so is it so strange? Or is it that it just goes against everything you have ever thought about before? Because Rolf's pair spoke design goes against every well-held conjecture about wheels and spokes that we all thought we knew. It just so happens that trial and error with the components of the day lead to the common usage of 36 spoke wheels in the 60's and 70's and so now it seems that everyone is believing it like it's gospel. I just want to know one way or the other based facts and science if it really is the best way to build a wheel. If so, every wheel I will build from now on will be 36 spoked. 32 spokes be damned! But I want proof.
Agree and disagree.....russw19
Mar 12, 2003 5:01 PM
Anyways, having just read the post below about Sheldon Brown's reply.. I will just drop this question and move on. It's not like the answer is going to change the world anyways...

Have fun riding everyone, it seems that spring has finally hit most areas now!

Russ
Your weight + NYC potholes = 36 spokesBergMann
Mar 11, 2003 3:14 PM
Particularly on a fixed gear bike, on which you'll be hitting all kinds of stuff (stopping taxis, pedestrians, etc.) it'll be practical to have something bombproof.

I'm only 170, but have an old set of 36 spoke, 14 gauge, brass-nippled Campy Record/MA-40 wheels that I built over a decade ago and just can't kill.

These days I MTB on _extremely_ rocky terrain with 32 spoke wheels w/ alu nips, but they wind up on the truing stand every couple months. It's a question of priorities - I find it worth it for the climbing benefits.

For an around-town beater though, I'd definitely go the bombproof route.

As for spoke tension, Mr. Grumpy's right -- the worst thing you can ever do is under-tension your wheel -- first you'll ride it out of round, then you'll spend the rest of your life cursing and re-truing the thing.
My tragic 32-spoke experience...cory
Mar 12, 2003 9:07 AM
I'm a little heavier than you, and I'd always used 36-spoke wheels with very few problems. A few years ago I had an excellent local shop build a new rear wheel, and I let them talk me into 32 spokes and alloy nipples on a Velocity Deep V rim. I had doubts, but the owner weighs about 150, and he never had problems with HIS...
The thing was a pain from the start. I had more trouble with it in three months than I'd had with my previous wheels in two years. The guy rebuilt it for free after the fourth or fifth failure (mostly from the nips, which stripped out or snapped off), but it still wasn't right. He finally laced up the same thing with 36 holes and brass nips for the cost of parts, and no more trouble.
Alum nipplesmcteague
Mar 12, 2003 11:25 AM
I think your bad wheel experience has more to do with the use of aluminum nipples on rims lacking eyelets than it does with 32 vs 36 spokes. I suspect that if the dealer rebuilt using brass nipples and 32 spokes the wheels would be reliable as well.

Tim McTeague
...More information pleasezmarke
Mar 12, 2003 1:30 PM
I appreciate all the responses and like all good discussions one must weigh the opinions.

It seems that all things being equal, same build quality, same rims, same spokes, same nipples, etc.,...

a 36 spoke wheel is just going to be stronger and/or maybe it is only the heavier riders like myself that are going to notice the difference.

Based on the responses I would probably use Mavic MA3s with 36 spokes to build a wheelset for my commuter/single speed since it will take more abuse. If my current 32 spoke road bike wheelset keeps giving me trouble, I will build a new set and use CXP-33s or Open Pros with 36 spokes.

Anyone care to agree or disagree?
...Sheldon Brown Says...zmarke
Mar 12, 2003 1:33 PM
The text of an email I sent to Sheldon Brown (sheldonbrown.com/harris) and his response.

------------------------------------------------------
I was looking through your site today to find an article and/or discussion on the merits of 32 versus 36 spokes when building a 700c wheel for a road riding or commuting bicycle but could not find anything. Is it there in a place that I could not find?

If you have not written one, do you know of anyone who has?

Thanks.

-------------------------------------------------------

36 is stronger, 32 is lighter. That's it.

I generally like to have more spokes in back than in front. I would consider 36 rear/28 front to be all around superior to 32/32, for the same total number of spokes.

All the best,

Sheldon
Spoke number vs. spoke guageOp en zie goed
Mar 12, 2003 2:04 PM
Tangentially related query:
If my math is correct, it is possible to build a 36 spoked wheel for less wt than a 32 by using lighter spokes. So which would be stronger, with same wheel build, hubs, nipples, etc: 32 hole DT comp 14/15, or 36 hole 15/17?

I ask b/c I would like light wheels (who wouldn't) but am not sure I want the fragility that should come with smaller gauge spokes.

Interested to hear the take on this.

MRT
Spoke number vs. spoke guageDaveLobster
Mar 12, 2003 2:48 PM
I will go out on a limb and answer that a 36 spoke wheel with 14/17 (DT Revo, Sapim Laser, Wheelsmith XL) will be both lighter and stronger than a 32 spoke wheel with 14/15's (DT Competition, Sapim Race).

According to Sapim, their 14/17 spokes are STRONGER than their 14/15 spokes. I attest to this because I built a set of wheels for a 210-+lb buddy who is hard on equipment with 32/32 3x Lasers, and he has never had a spoke-related problem with them. I have also had 2 sets of wheels with Lasers and no problems on either(175-185lbs). In fact, I have heard credible reports that the Sapim CX-Ray spoke (basically an aero Laser) is being used extensively by professional downhill racers.

So having more spokes which are stronger will definitely give you a stronger wheel, everything else being the same. I would recommend you stick with 14/17's over 15/17's due to the fact that the 14 gauge end fits better in the holes in the hub (read Schraner's book on why spokes break). -Dave
strongly agree with your post!satanas
Mar 18, 2003 7:00 AM
Also, there's a reason why all those tandems and expedition touring bikes use 36, 40 or 48 spokes - they're stronger.

My experience is that customers who had trouble with 32 spokes/light rims generally had zero problems with 36 spokes/deep section rims. Bigger tyres help too.

Agree that more spokes in front is sensible if weight is an issue. Trad UK bikes used 32/40 spokes, and I find 28/32 works for me. Thorn currently recommend 36/48 for heavy duty RTW use. OTOH, I've *never* had problems with any of my 36/36 wheels, crashes excepted.

All in all, it's probaly easiest to stick with 32/32, 32/36 or 36/36 as the rims and hubs are easier to get than with the more "peculiar" drillings...