Another bike science video explaining what asymmetric wheels are, and why they exist. More bike science: • Saucy Bike Science Support the channel! www.thebikesauce.com/
Do I NEED Asymmetrical Rims? No. Do I WANT Asymmetrical Rims? Yes. When I built a set of wheels last year using Hunt 4 Season SuperDura Disc rims and DT Swiss 350 hubs front and back, my spoke length calculations ended up coming out identical for both sides. In fact, it ended up being the same front and rear. That made getting spokes a lot simpler.
Also, from a wheel-building and reliability standpoint, you don't want to have too much of a difference between the drive and non-drive side spoke tension due to the fact that the maximum tension is "controlled" by the DS. In other words, when the DS spokes are fully tensioned (to allowable limit of the rim), if the angle difference DS to NDS is too large, then the tension in the NDS can be quite low...and in some cases, if the rim radial stiffness is also low, then it's possible to get in situations (such as hitting a bump) that causes the NDS tensions (in the contact patch area of the wheel) to drop to zero...at which point the spokes can begin loosening and/or fatiguing. As you mention, it also results in a less laterally stiff wheel structure. All good reasons to prefer asymmetric spoke hole arrangements.👍
Brilliant! More or less complex mathematical and physical causes to a problem ( the solution of which I have long-forgotten since school 😹) visualized in a neat and well understandable package. ... Although the practical bottom line whether to choose asymmetrical rims for wheel builds remains unsolved for me, because whenever I took care of sufficient and even spoke tension, neither me nor the kids had any broken spokes since more than 12 years.
I would argue that it's not as simple as "spoke holes" as then we would introduce Asymmetric stress on the rim,. Rather the rim as a whole is Asymmetric to compensate for this, and make an overall evenly tensioned structure. Love the vid & vibe, and surprised that auto-play can find good vids XD
Great topic, and very clearly explained! I've always wondered about the benefits of an asymmetric rim. My question is with the tension in the spokes being equal, but offset, any externally applied vertical load on the wheel will induce a weak axis bending moment in the rim. You can see this when you draw a free body diagram of the wheel with the normal force acting through the center of the rim/hub. The question is, is the benefit of a symmetric spoke tension preferred over symmetric stresses in the rim? Has anyone studied this in-depth enough to make that conclusion? Although, the eccentricity is small (a few mm) and with a trend towards wider rims in general perhaps the minor axis stresses and/or deflections are fairly low, even with big impact forces? It would be interesting to hear your thoughts. As a comparison, what about the benefits of using an asymmetric spoke diameter, spoke lacing pattern, or spoke count instead? Looking forward to your research results on mass damping of bicycle tires and rolling resistance.
Mechanics of materials has entered the chat. Hey Henry! I see what you’re saying. I suppose a small offset in spoke offset yields greater benefit in tension balance than drawback in bending moment, but would have to do the math to quantify.
Excellent video that discusses the merits of asymmetric rims. However, I'll also like to see some discussion on what kind of trade offs there are too, like how the rim itself has to be overengineered more to preserve rim strength. Just as you are giving the isosceles triangle back to the spokes, you are taking it away from the rim after all. I've also noticed there might be a way to mitigate the spoke angle problem besides offsetting the rim, by offsetting the hub flanges instead. I have a set of hunt gravel wheels that does that. What do you think? Is it a viable solution or am I missing a lot of information?
This is actually what the Cannondale AI offset aims to do. The Cannondale system makes the spoke angle nearly symmetric with traditional rims. Instead of offsetting the rim the frame is offsetted. This gives the stronger rear wheel but also larger chainring clearance and tire clearances. It didn’t seam to catch on though which is a bummer because it helped solve a few issues.
Nice scientific explanation! Could you also make a video on the calculation of Gear ratio, Gear range, Gear inches, Derailleur capacity and other such similar things along with their significance/application? It would be very useful to have a single video detailing on that as well other online utilities/websites that one would use for such things.
Would the width of a tire have any reflection on how fat the rim can move to the nondrive side? I'm thinking of fatbikes with 4 or 5 inch wide tires, thanks for the video!!
How long are the threads of the spokes??! I bought some that are only 4 mm long, a real pet peeve...I can't get enough tension.... I think I need to offset my rim to the hub!!! The rim and tire is not centered to the back frame... Don't know how much shorter the spokes needs to be the gear side.... I made new wheel with a wider rim, and now my tire is obviously wider...and now rubbing on the brake side....
If the rim is symmetric, does that mean that the drive-side spokes need to be shorter so that spoke tension difference vs. non-drive-side spokes is minimized? Edit: after some Googling, "Differential spoke selection is done to create ideal thread engagement on both sides. It does not equal out left and right side spoke tensions."
It’s both. You need different size spokes just to fit the build (ideal thread engagement), but the math doesn’t lie - it balances spoke tension as well
So I get the explanation of why asymmetric profiles better distribute tension between DS and NDS spokes, but did we ever address whether you *NEED* them? I've had symmetric and asymmetric spoke wheels and never broken spokes by cornering (admittedly, mostly road miles). Do you MTB guys break spokes a lot more often / break appreciably fewer spokes with asymmetric rims?
Haha touché. ‘Need’ is always subjective anyways. It is definitely true the drive side rear spikes break way more frequently than non drive side (presumably due to the traditionally higher tension)
And he said: “this is pretty straightforward”, yeah right! Man you need to get together with the band again; I miss the nerd (Sauce), the nuts (Spindatt) and the hippie (Russ)… those shows were damn fun to watch
Ritchey makes asymmetric rims, so I bought sets in 650b and 700c sizes. I can tell you, they are bombproof. Tom has been designing for 50 years, enough said!
What extent of use in your opinion will asymmetrical rims be necessary because symmetrical rims can hold quite some load before the need the switch to asymmetrical rims?
Not a question of need really. Imagine carrying 100kg. Would you rather hold 50kg in each arm, or 80 in one and 20 in the other? Asymmetrical rim holes just balance out the tension a bit
Now I know why I like listening to your videos, because you have a brain, and you just revealed your day job, that explains it 😄😂 Hello 👋 from down under I have been cycling most of my life,including at a competitive level. Now gravel rules, well my favourite. But always been nerdy about the mechanics of cycling, that’s my background 😂
I bought the DT Swiss RR440 asymmetrical rim without knowing that it was asymmetrical (I have no chance of returning it), unfortunately there are not many rim options in my region... I had this rim knitted for the front wheel of my road bike without disc brakes. The appearance of the wires is symmetrical when viewed from above. Will I experience any problems such as stability or instability while driving?
Bike science is awesome! I was disappointed when the bike industry switched to 148 drop out spacing. Many hub companies didn’t widen the hub flanges and just added longer axles or end caps. So essentially the wheel strength remained the same. True the asymmetrical rim helps with strength but the width of the hub flanges also plays an essential role. So with that in mind you can see why some companies have gone to super boost 157mm axle spacing. Pivot,Evil,Knolly and Devinci to name a few. So my point is, if you’re buying a new wheel set, take a look at the flange width too. Personally I have some SS specific hubs for my single speedy Mtn bikes and those hubs have about the same flange width as SB157mm geared hubs. I’m not a big guy (160#) and definitely not a DH racer or freerider that’s smashing down the mountains,but I do think that a stronger wheel is important. The SuperBoost 157 standard hasn’t really gone mainstream but it’s obviously a stronger wheel than Boost 148 that wasn’t much better than standard 142.
I think you mean 142 drop out spacing. The 142 hub dimension is identical to 135 just with a longer axle. I believe the idea was to add slots in the dropout so you could install the wheel easier. The 148 is where they widened the hub flange spacing from the 135/142 design👍
@@DeeCountVideos they only widened the hub flange 3mm on each side and this is not the standard. Some hubs don’t even do the the full +6mm. All the hub manufacturers have to do is ensure the axle width is 148 and the non-drive side is properly aligned for the brake rotor.
This is on an old 126mm dropout road bike, but it's possible to get 9 cassette cogs in the space for 6 freewheel cogs. Actually shorten the 8,9,10 speed freehub by grinding the end leaving just a few threads for the lock ring. Grind a few threads off the lock rings. Grind the spacers on the axle so the last cog nearly touches the frame. Lock nut spacing has to equal 126mm. This gives a wheel dish lower than stock. Use 10 or 11 speed cogs to build the cassette. If a large sprocket, say 36 tooth freehub is used, it may be possible to grind the back of the cassette spider and get 10 cogs instead of 9. The axle needs to be cut shorter so the quick release still works. Time moves on, and "standards" shift, but ingenuity can upgrade your bike when it becomes obsolete. I wanted to get a Velocity offset deep section rim to further dish reduction, but they weren't available. Learn to build wheels and that will help with all of the above.
@@davidburgess741 sounds like a fun project. I’ve thought about using my old Hadley 135 bolt on hub to build up Pinion drive frame with a Gates Carbon belt drive. A townie or commuter bike. My old Hadley’s are a dark blu ano and still work great plus look amazing. The front hub is a 9mm through axle that fits old QR forks
@@hardmtnbiker Pinion drive sounds great, but the belt drive looks like it may have flopped commercially. It was available with CoMotion bicycles as seen on the retired Bicycle Touring Pro website. His older Australian buddy did wind up with some kind of problem with his Pinion drive on another make bike. Those systems are slightly less efficient than the derailleur system and are really expensive and heavy. If you want efficiency and reliability get a fixed gear! Tremendous mechanical efficiency, but horrible biometric efficiency! It depends on how you weight the usual factors. You can only choose 2. Your options grow when you learn to build wheels. Ali Clarkson and Jim Langley have made the best CZcams videos IMHO. I've actually built wheels occasionally for 30 years that worked, but these guys raised my game. Jim will also respond to questions of subscribers promptly. Penny Farthings? Well, he's done that too! Very interesting rabbit hole!
This is badass man I've got a set of affordable FSA NS Asymmetrical wheels, they are my 1 of 2 non OEM wheelsets that I own for my bikes and lemme tell you even tho they're only a 28 spoke wheelset vs all of my other 32 spoke wheels they feel tremendously stiffer, maybe becuase they require a higher spoke tension than a 32? I have them mounted with some 42mm Pathfinder pros tubeless 30psi front 35psi rear, soon as I got them mounted up to my Frankenverge (Specialized Sirrus X3 converted to drop bars IE: poor mans Diverge) Immediately it felt like I was riding on 28mm slicks at 100psi no joke them things feel stiff! Side note I dont really ride them that much because the hub to me is waay too loud even after throwin a bit more grease in there, they are a good warning for pedestrians as they can usually hear me coming before I get close enough to anounce myself.
german civil engineer here, thanks for porting me back into my second semester :D. Im glad I still understood what you were talking about.
Well I guess we should start addressing you by “Professor Sauce” from here on out….
‘Bike Sauce’ is weird enough. 😀
Professor sauce would probably have an awesome barbeque joint
Engineering Explained for bikes! I like it!
Do I NEED Asymmetrical Rims? No.
Do I WANT Asymmetrical Rims? Yes.
When I built a set of wheels last year using Hunt 4 Season SuperDura Disc rims and DT Swiss 350 hubs front and back, my spoke length calculations ended up coming out identical for both sides. In fact, it ended up being the same front and rear. That made getting spokes a lot simpler.
Also, from a wheel-building and reliability standpoint, you don't want to have too much of a difference between the drive and non-drive side spoke tension due to the fact that the maximum tension is "controlled" by the DS. In other words, when the DS spokes are fully tensioned (to allowable limit of the rim), if the angle difference DS to NDS is too large, then the tension in the NDS can be quite low...and in some cases, if the rim radial stiffness is also low, then it's possible to get in situations (such as hitting a bump) that causes the NDS tensions (in the contact patch area of the wheel) to drop to zero...at which point the spokes can begin loosening and/or fatiguing. As you mention, it also results in a less laterally stiff wheel structure. All good reasons to prefer asymmetric spoke hole arrangements.👍
Ditto... exactly the point I was going to make, but you said it better than I could. Thanks.
fantastic. learned so much. always wondered what the science behind the asym rims were. Clear explanation.
Very good lesson, for sure you are a good professor!
Love your videos! Mech Eng in its most interesting form! Keep on making epic content!
You know it's about to get serious when the Science hat appears!
😆😆
I love that you literally put your Science hat on for this video 😂
You know it!
@@TheBikeSauce dad jokes, gotta love em 😂
Thank you, great explanation!
As a fellow ME, please keep bringing the tech content. This explanation was sufficiently nerdy while still being understandable. Thanks!
Great vid! Super informative!!!
I used to shy away from asymmetric rims but now I think I want them! Haha
Brilliant! More or less complex mathematical and physical causes to a problem ( the solution of which I have long-forgotten since school 😹)
visualized in a neat and well understandable package.
...
Although the practical bottom line whether to choose asymmetrical rims for wheel builds remains unsolved for me, because whenever I took care of sufficient and even spoke tension, neither me nor the kids had any broken spokes since more than 12 years.
I would argue that it's not as simple as "spoke holes" as then we would introduce Asymmetric stress on the rim,. Rather the rim as a whole is Asymmetric to compensate for this, and make an overall evenly tensioned structure.
Love the vid & vibe, and surprised that auto-play can find good vids XD
Bro you deserve more subs but you got my respect!
Nolan, you freaking legend!!! So good dude!
😀
Great topic, and very clearly explained! I've always wondered about the benefits of an asymmetric rim. My question is with the tension in the spokes being equal, but offset, any externally applied vertical load on the wheel will induce a weak axis bending moment in the rim. You can see this when you draw a free body diagram of the wheel with the normal force acting through the center of the rim/hub. The question is, is the benefit of a symmetric spoke tension preferred over symmetric stresses in the rim? Has anyone studied this in-depth enough to make that conclusion? Although, the eccentricity is small (a few mm) and with a trend towards wider rims in general perhaps the minor axis stresses and/or deflections are fairly low, even with big impact forces? It would be interesting to hear your thoughts. As a comparison, what about the benefits of using an asymmetric spoke diameter, spoke lacing pattern, or spoke count instead?
Looking forward to your research results on mass damping of bicycle tires and rolling resistance.
Mechanics of materials has entered the chat. Hey Henry! I see what you’re saying. I suppose a small offset in spoke offset yields greater benefit in tension balance than drawback in bending moment, but would have to do the math to quantify.
Excellent video that discusses the merits of asymmetric rims. However, I'll also like to see some discussion on what kind of trade offs there are too, like how the rim itself has to be overengineered more to preserve rim strength. Just as you are giving the isosceles triangle back to the spokes, you are taking it away from the rim after all.
I've also noticed there might be a way to mitigate the spoke angle problem besides offsetting the rim, by offsetting the hub flanges instead. I have a set of hunt gravel wheels that does that. What do you think? Is it a viable solution or am I missing a lot of information?
This is actually what the Cannondale AI offset aims to do. The Cannondale system makes the spoke angle nearly symmetric with traditional rims. Instead of offsetting the rim the frame is offsetted. This gives the stronger rear wheel but also larger chainring clearance and tire clearances. It didn’t seam to catch on though which is a bummer because it helped solve a few issues.
Tom Ritchey did the same thing, only many years before Cannondale.
They apparently abandoned this technology in their latest Topstone bikes. Too bad for science, but good for compatibility.
Nice scientific explanation! Could you also make a video on the calculation of Gear ratio, Gear range, Gear inches, Derailleur capacity and other such similar things along with their significance/application? It would be very useful to have a single video detailing on that as well other online utilities/websites that one would use for such things.
Great idea
Can you do a video on truing the wheels? Cheers!
Would the width of a tire have any reflection on how fat the rim can move to the nondrive side? I'm thinking of fatbikes with 4 or 5 inch wide tires, thanks for the video!!
Oh the formulas! I miss college! hahaha! Good presentation bro!
.... I'll take your word for it. But thanks for showing your work 😀👍
😆😆
How long are the threads of the spokes??! I bought some that are only 4 mm long, a real pet peeve...I can't get enough tension....
I think I need to offset my rim to the hub!!! The rim and tire is not centered to the back frame... Don't know how much shorter the spokes needs to be the gear side....
I made new wheel with a wider rim, and now my tire is obviously wider...and now rubbing on the brake side....
Would asymmetrical rims help any more on a Cannondale asymmetrical frame?
YES - Next question ✌️
Nice video. Question: how to center the rim then? Meaning that is symmetrical comparing with the bike. Thanks
It’s dished off center wrt the flanges, but centered on the bike
If the rim is symmetric, does that mean that the drive-side spokes need to be shorter so that spoke tension difference vs. non-drive-side spokes is minimized?
Edit: after some Googling, "Differential spoke selection is done to create ideal thread engagement on both sides. It does not equal out left and right side spoke tensions."
It’s both. You need different size spokes just to fit the build (ideal thread engagement), but the math doesn’t lie - it balances spoke tension as well
So I get the explanation of why asymmetric profiles better distribute tension between DS and NDS spokes, but did we ever address whether you *NEED* them? I've had symmetric and asymmetric spoke wheels and never broken spokes by cornering (admittedly, mostly road miles). Do you MTB guys break spokes a lot more often / break appreciably fewer spokes with asymmetric rims?
Haha touché. ‘Need’ is always subjective anyways. It is definitely true the drive side rear spikes break way more frequently than non drive side (presumably due to the traditionally higher tension)
And he said: “this is pretty straightforward”, yeah right! Man you need to get together with the band again; I miss the nerd (Sauce), the nuts (Spindatt) and the hippie (Russ)… those shows were damn fun to watch
😆 the nerd, the nut, and the hippie. Spot on
Ritchey makes asymmetric rims, so I bought sets in 650b and 700c sizes. I can tell you, they are bombproof. Tom has been designing for 50 years, enough said!
Love the math! Nice, gold 1st gear cog on that bike, by the way.
*
Those polished rims!!!!!!!!!!!!
What extent of use in your opinion will asymmetrical rims be necessary because symmetrical rims can hold quite some load before the need the switch to asymmetrical rims?
Not a question of need really. Imagine carrying 100kg. Would you rather hold 50kg in each arm, or 80 in one and 20 in the other? Asymmetrical rim holes just balance out the tension a bit
Now I know why I like listening to your videos, because you have a brain, and you just revealed your day job, that explains it 😄😂
Hello 👋 from down under
I have been cycling most of my life,including at a competitive level. Now gravel rules, well my favourite. But always been nerdy about the mechanics of cycling, that’s my background 😂
I bought the DT Swiss RR440 asymmetrical rim without knowing that it was asymmetrical (I have no chance of returning it), unfortunately there are not many rim options in my region... I had this rim knitted for the front wheel of my road bike without disc brakes. The appearance of the wires is symmetrical when viewed from above. Will I experience any problems such as stability or instability while driving?
You want asymmetrical, it’s a better design
Bike science is awesome! I was disappointed when the bike industry switched to 148 drop out spacing. Many hub companies didn’t widen the hub flanges and just added longer axles or end caps. So essentially the wheel strength remained the same. True the asymmetrical rim helps with strength but the width of the hub flanges also plays an essential role. So with that in mind you can see why some companies have gone to super boost 157mm axle spacing. Pivot,Evil,Knolly and Devinci to name a few. So my point is, if you’re buying a new wheel set, take a look at the flange width too. Personally I have some SS specific hubs for my single speedy Mtn bikes and those hubs have about the same flange width as SB157mm geared hubs. I’m not a big guy (160#) and definitely not a DH racer or freerider that’s smashing down the mountains,but I do think that a stronger wheel is important. The SuperBoost 157 standard hasn’t really gone mainstream but it’s obviously a stronger wheel than Boost 148 that wasn’t much better than standard 142.
I think you mean 142 drop out spacing. The 142 hub dimension is identical to 135 just with a longer axle. I believe the idea was to add slots in the dropout so you could install the wheel easier. The 148 is where they widened the hub flange spacing from the 135/142 design👍
@@DeeCountVideos they only widened the hub flange 3mm on each side and this is not the standard. Some hubs don’t even do the the full +6mm. All the hub manufacturers have to do is ensure the axle width is 148 and the non-drive side is properly aligned for the brake rotor.
This is on an old 126mm dropout road bike, but it's possible to get 9 cassette cogs in the space for 6 freewheel cogs. Actually shorten the 8,9,10 speed freehub by grinding the end leaving just a few threads for the lock ring. Grind a few threads off the lock rings. Grind the spacers on the axle so the last cog nearly touches the frame. Lock nut spacing has to equal 126mm. This gives a wheel dish lower than stock. Use 10 or 11 speed cogs to build the cassette. If a large sprocket, say 36 tooth freehub is used, it may be possible to grind the back of the cassette spider and get 10 cogs instead of 9. The axle needs to be cut shorter so the quick release still works. Time moves on, and "standards" shift, but ingenuity can upgrade your bike when it becomes obsolete. I wanted to get a Velocity offset deep section rim to further dish reduction, but they weren't available. Learn to build wheels and that will help with all of the above.
@@davidburgess741 sounds like a fun project. I’ve thought about using my old Hadley 135 bolt on hub to build up Pinion drive frame with a Gates Carbon belt drive. A townie or commuter bike.
My old Hadley’s are a dark blu ano and still work great plus look amazing. The front hub is a 9mm through axle that fits old QR forks
@@hardmtnbiker Pinion drive sounds great, but the belt drive looks like it may have flopped commercially. It was available with CoMotion bicycles as seen on the retired Bicycle Touring Pro website. His older Australian buddy did wind up with some kind of problem with his Pinion drive on another make bike. Those systems are slightly less efficient than the derailleur system and are really expensive and heavy. If you want efficiency and reliability get a fixed gear! Tremendous mechanical efficiency, but horrible biometric efficiency! It depends on how you weight the usual factors. You can only choose 2. Your options grow when you learn to build wheels. Ali Clarkson and Jim Langley have made the best CZcams videos IMHO. I've actually built wheels occasionally for 30 years that worked, but these guys raised my game. Jim will also respond to questions of subscribers promptly. Penny Farthings? Well, he's done that too! Very interesting rabbit hole!
I was too distracted by that Outback. Please tell me you’ll present it in more detalj for us soon?
Ha, yea Outback videos in the works
New sub for you.
You've convinced me to buy monocoque carbon wheels
4:52 its not just offset drilling, the entire rim profile and shape is offset. Its no longer a perfect pyramid
Spot on! Drawings are schematic
how about asymmetric hubs?
Millions already exist which is the problem, we need more symmetrical hubs
This is badass man I've got a set of affordable FSA NS Asymmetrical wheels, they are my 1 of 2 non OEM wheelsets that I own for my bikes and lemme tell you even tho they're only a 28 spoke wheelset vs all of my other 32 spoke wheels they feel tremendously stiffer, maybe becuase they require a higher spoke tension than a 32? I have them mounted with some 42mm Pathfinder pros tubeless 30psi front 35psi rear, soon as I got them mounted up to my Frankenverge (Specialized Sirrus X3 converted to drop bars IE: poor mans Diverge) Immediately it felt like I was riding on 28mm slicks at 100psi no joke them things feel stiff!
Side note I dont really ride them that much because the hub to me is waay too loud even after throwin a bit more grease in there, they are a good warning for pedestrians as they can usually hear me coming before I get close enough to anounce myself.
We don't "need" them, but asymmetrical drilled rear spoke holes is a must for 99% of bikes, but no one does it
So... Symmetric rims are pointless?
What are those beautiful wheels?
Haha Hunt carbon gravel x wide
Baby, talk bike nerdy to me.
I feel like I'm gonna work here?
Can I audit your classes? I'll sit in the back and be quiet, I promise.
🤘
ME here. yahhhhhh! mmmmmmmm, brain happy
I would get a crash on my ride while thinking this 😅
Fickn hat needs to be a reatil item for the masses !!!
Haha it is. It’s from skratchlabs
I have 5 spokes and none of these asymmetrical problems.
I'll NEVER look the wheels the same way...
😆
Can you make your content accessible by having closed captioning instead of the dreaded auto captioning please? (I'm Profoundly Deaf)
Ah yes, more of this. Good ole boring and niche bicycle engineering content!
Would asymmetrical rims help any more on a Cannondale asymmetrical frame?
Probably not, because the rim is shifted to NDS.
It will create more problems, because you will have to have higher tension on NDS than on DS