Dirt bike frames | Offroad Engineered

What the hell is longitudinal or lateral stiffness you read on every new MY bike press releases? And why are there steel and aluminium frames? Is it only to save weight?
The doubts will finally be uncovered!
0:00 Intro
0:56 Longitudinal stiffness
1:39 Torsional stiffness
2:14 Lateral stiffness
3:25 Changing the stiffness
4:13 The shift to aluminium
4:48 Mechanical properties
5:44 Manufacturing properties
6:21 R&D consequences
7:00 Cherries on top for Alu
7:21 End
I want to give a huge shoutout to Angus MacDonald from ‪@MCDMedianz‬ for providing such high-quality slow-mo footage. Without him, this video wouldn't be so easy to understand, so please check his channel and subscribe!
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#stepstopodium #offroadengineered #frames

[@mohba01]

Hey Man, nice explaination. Today, with current sofwares (like Catia) we can figure a 3D in movement to demonstrate the simple and easy way to calculate what happens during acceleration, braking when hitting a bump and so on. But with regards to demostration of how much material to use and what material to use, and because anything speical will cost money, most steel frame for eg use AISI 4130 alloy steel and some types of reynolds steel as there have been enough data fed for them regarding thier "Yield Criterion" and how much Von Mises Stress the material can take. Ofcource this is the reason why ktm sticks with steel frame, however japanese manufactures have focused more on different methods of extruding, casting and forging aluminum and mixing all three together to get the same "Yield Criterion" and how much Von Mises Stress the material can take ! funnily these are studies i gathered when i worked for a bicycle company that was planning to make carbon frames back in the days and it was indeed a lot of upstream learning for me. appreciate your videos, they are very englitening !

[@StepstoPodium]

Thank you so much for your input and I'm glad you liked it! 😄

[@ryangreen1588]

Dude, your breakdown, delivery of info and animations are awesome. Thanks

[@StepstoPodium]

Thank you!! 😄🙌

[@Outdoorsnmotors]

I had a kx450 with aluminum frame, cracked the frame on a cased jump, ended up switching to Ktm with steel frames because they will flex more before it cracks.

[@str5128]

no, its because it's a kawasaki lmao

[@filippomazzola5488]

Excuse me, I don't understand why you say that aluminum is stiffer than steel? Okay, we also need to consider the section of double-beam aluminum frames, but a tubular steel frame is significantly more rigid. Considering that, as you presented in the video, the elastic modulus of steel is higher = more rigid, aluminum is more flexible and therefore less rigid; it also has an FCC crystalline structure. Even considering the higher performing aluminum alloys, like the 7000 series, they have a significantly lower elastic modulus than quenched and tempered steel. For confirmation, the sections of aluminum frames are larger because if they used the same sections as steel, they would bend too much. Aluminum is less rigid than steel. What you told about the stiffness of alluminium frame is because they have more frame section and that the reason why is stiffer? thanks love your channel

[@StepstoPodium]

Essentially, yes!

[@rideyourbike]

Your explanation is simple and priceless. Congrats and thanks.

[@StepstoPodium]

Thank you soooo much! 🙌😄

[@AntiStressKit]

Oooh, I was waiting for that video to come out 🙂. Indeed, knowledge is power and I appreciate the useful information. Cheers 🍺

[@StepstoPodium]

Thank you so much Ariel for never skipping a video! 😃🙌💪

[@lucafacibeni1396]

Great article! Clear, simple and exhaustive on the topic. Congratulations

[@StepstoPodium]

I appreciate it Luca! 🙌💪

[@codyjames8424]

Love your videos man. Thank you!

[@StepstoPodium]

Thank you so much Cody! I really appreciate it 🙌🙂

[@free-birdrocker8809]

Bubba, good lesson. I rode a buddy's 98 250R and the frame was stiff as a brick, I have a 89 250R and its much nicer to ride. Im sure the new ones are improved, but everybody is a winner. We say Luminium here in cowboy land.🤠

[@StepstoPodium]

Couldn't agree with you more! 😄 As long as we understand each other, you can even call it potato 🤣

[@josephgreenlee6213]

Thanks for the video I’ve went over this so many times with co workers. Working at a Honda dealership they always ask me why I still choose my KTM, now I’ll have this video to show them instead of wasting my time explaining! Thanks!

[@StepstoPodium]

Nice! Glad I could help! 😄🙌

[@vinceking7878]

Exerlent video, first time this has been explained. Been looking for this.

[@StepstoPodium]

Thank you! Really glad I shed you some light on this matter 😄🙌

[@Jap_masters]

Espetacular 👌🏼

[@StepstoPodium]

Muito obrigado!! 😃

[@topstar3]

Another home run video my man!

[@StepstoPodium]

Thank you!😄🙌

[@trevornugent9680]

Great vid mate

[@StepstoPodium]

Thank yoooouuuuu 🙂

[@MCDMedianz]

Top work mate! I did the easy work!

[@StepstoPodium]

I appreciate it! 😃

[@nvmcrider8475]

Great Information! Which engine mounts can you modify to get more lateral flex or softness on an aluminum frame Yamaha WR?

[@luisquinta3137]

Excelente...

[@StepstoPodium]

Obrigado Luis!!!

[@willygt2379]

new sub

[@Chris-uh3cm]

I love your vids they help so much you don't even know. Can you do a vid on clutchless shifting?? I believe its bad but I want to know from you

[@StepstoPodium]

Thank you so much for that Chris, I really appreciate it! 🙌 What do you mean with clutchless shifting? 👀

[@ktkace]

CRO-moly (KTM / KOVE/ CFMOTO ) hi tensile steel can handle 980 MPA (VS 300 MPA for alu and 480 mild steel )

[@christoph3500]

great video too! do you know the exact aluminium material used on the dirtbike frames - somewhere i have read it is 7005 series - can you verify ? 6061 aluminium would need quiet sophisticated heat treatment...! But as there are homemade garage frame mods i strongly suspect the frame material to be some kind of 7000 series aluminium

[@StepstoPodium]

I hope you'll say that to all offroad engineered videos 😆 thank you very much 🙌 I don't know, but I'm guessing it's one of those two, yeah. They seem to have the best mechanical properties for this use

[@samammerman6075]

The major hard enduro brands only use some type of chrome Molly or whatever that specialty steel is,,,, you will not see any of the aluminum frame bikes on the podium on hard enduro or Woods riding, when it comes to the pro.... so I'm wondering how they pull it off on motocross Supercross unless that's really not the bike but just a façade like NASCAR vehicles

[@xenzie-yt8979]

Hello and thank you so much for this video I learned so much but I do have a small question. So I own a Honda cb160 r which is mostly used in India and Sri Lanka. I am so scared to ride on some roads. I prefer only to ride in very flat and smooth roads because I fear that it might damage my bike frame and also to mention I have OCD. I feel that if I write on roads that are not very flat and smooth my frame Bend and crack. Is what I'm thinking correct or am I over thinking too much hoping for your answer thank you so much in advance

[@StepstoPodium]

Hello! Of the frame has no cracks or os not compromised in any way, I'm sure it won't break!

[@maneljoaquim4047]

Que video!

[@StepstoPodium]

Muito obrigado manel! 😄

[@Offroadreel]

I just switched from an aluminum frame to a steel Ktm frame bike, the steel frame is way better, not too mention my last brand new kx450 aluminum frame cracked pretty bad.

[@ricardofonseca24]

Se calhar uma pergunta estúpida 😁 Se os quadros de motocross para enduro teem rigidez diferentes para cada propósito, porque alguns dos prós usam motos de cross para fazer enduro?

[@StepstoPodium]

Não existem perguntas estupidas no S2P grande Ricardo! 😄 Penso que essa questão tem mais haver com preferência dos pilotos do que propriamente o quadro em si. Uma mota de cross tem um comportamento inerente que muitos pilotos preferem, nomeadamente motor mais agressivo, suspensões mais firmes, etc, mas claro que certos prós preferem algumas de cross especificamente pelo quadro. Lembra-te que tudo o que disse são orientações gerais que se observam entre ps fabricantes e não especificamente uma regra escrita em pedra. Os fabricantes correm nos mundiais r tudo mais, mas no fundo o que querem é fazer uma mota para venda ao publico (e para o comum piloto), por isso nem tudo pode ser feito consoante as escolhas especificas de certos pilotos de topo (que a grande maioria tem gostos que fogem completamente à norma! Um exemplo é o Billy Bolt) Espero ter ajudado a esclarecer 🙂

[@ricardofonseca24]

Por isso é que existem várias marcas com diferentes tipos de ciclisticas diferentes, ao gosto de cada um. Esses ditos pilotos não são humanos, são extraterrestres 😂 Obrigada Luís por nos mostrar o porquê das coisas. Não demores com o próximo vídeo 😁

[@StepstoPodium]

Exactamente!! Gosto muito dos meus subscritores porque são pessoas que pensam nas coisas!! 😄💪 Ando a fazer o meu melhor com o tempo que dá, mas depois de uns dias de descanso, já vou começar com o proximo! 😁💪

[@thra5herxb12s]

He ll=ooks like a magician 🤣

[@cowpker4life333]

Thought aluminum frames cost alot more due to needing more r&d for getting flex etc all correct. Why chinese bikes staying steel still. Also aluminum frame gives lot better stability at speed vs steel doing lot better abosrtion of bumps

[@MiikeyLawless]

As stated in the video, steel is more labor intensive. What does China have over Japan? A cheap labor force. A bad steel frame is still a bad frame, same for aluminum. But a perfect steel frame has better characteristics than a perfect aluminum frame. That said, give me good geometry over all else.

[@6Twisted]

So why do cheap bikes use steel frames and expensive bikes use aluminum?

[@StepstoPodium]

Steel is cheaper and easier to weld. Requires less r&d to make proper welds!

[@6Twisted]

@@StepstoPodium You said the opposite thing in the video?

[@Paul-gu2lv]

The joke is on you. I've got a plastic frame.😂

[@StepstoPodium]

😂😂😂

[@Paul-gu2lv]

@@StepstoPodium 😁 I'm joking. It is a Yamaha aluminium frame, but it's mostly covered by acerbis guards so it is actually plastic on the outside. 😉😂. Great and very informative video though. Thanks!

[@StepstoPodium]

Ahah! 😂😂

[@commonstragedy]

So, it's spelled "aluminum" yet you're saying 5 syllables. Huh? (Yes, I'm trolling.)