You can watch a few videos from Peak Torque and know more about bikes than watching 200 hours of videos from bike reviewers. Much more useful information than the standard approach.
@ Which means it's stiffer, which means it smoothes out chatter better, which means it's lighter, which means higher price tag, which means it fades fast too ;-p ;-p
Just came across your channel and loved it. As a mechanical engineer and lifelong bike rider myself, I was more than happy to finally hear someone making the right considerations about the frame materials and geometry. Thank you and keep it up!
Interesting to read the comments and a few things i didn't mention in the video which are important: Aluminium will likely have larger second moment of area tubes to meet the strength and fatigue requirements (due to having a lower yield and fatigue strength). Thus, the Al bike of equal mass will likely be stiffer due to the second moment of area being higher and having more material volume to play with. I did not address strength or fatigue in the video but its important. For Al frames its normally the driving factor especially near heat affected zones (welds) where the metallurgy changes.
I enjoyed the video, but isn't this contradicting the point that marketing around Ti frames is bullshit, as the majority of top comments appear to interpret the video as meaning? In the video you hypothetically compared Al and Ti frames of the same mass and tube shapes, saying they wouldn't noticeably differ in stiffness. But that's not how they're designed so that's not the reality of the differences between the frames on the market. It's up to the frame designer(s) to decide what qualities they will best achieve with the material, and there are different things achievable with different materials; particularly, as you stated, when regarding yield and fatigue strength. So the real point is: A frame isn't inherently 'better' because of the material it's made of, but one can be designed 'better' than another by exploiting the material used, depending on what 'better' means to you.
@@ccmmrrnn you're dead right and thanks for the comment. I had filmed a cut about in reality how the Al frame would be slightly stiffer and have more 'volume' to work with for the same mass, how the tube shapes would able to be larger to increase I, and reduce the fatigue stress. Im kicking myself for not including now, but it was getting to a bit of a 15min monologue. Not my best work, but there we are.
@@PeakTorque Appreciate your reply. Note: 'have to' be larger to 'reduce fatigue stress'. Enjoy the clicks from people thinking this is some kind of 'gotcha', which I suspect you intended, given the title.
@@ccmmrrnn I was taking the video in very much the 'like for like' comparison of materials, and dealing with some of the 'magic' material properties that people assign to what the frame is from. You're absolutely right that design can follow material, and that will effect the ride and other characteristics - be that complex shaping with composites, or tube constraints with heavy materials like steel - but think some of the key points made were valid.
To completely ignore the yield component is quite misleading. Your comparison of many of the factors including the resonant frequency change dramatically when you have a much thicker Al tube at 8KSI vs Ti (3Al-5V) at 79.9KSI or even steel at 36KSI. I do agree with your seat post comment, cheap Al posts act about like bar stock as they are so thick walled, Ti, high end Al or plastic (carbon) all can have a big effect on comfort and perceived ride quality. It would be interesting to see various equivalent bike frames put on a shaker table.
I have a Ti gravel bike and a Ti hardtail 29er-love them both, bought them because as a retired engineer I just love the corrosion resistance and look of titanium. I also have a carbon road bike which I save for the good weather, my gravel bike with road tyres fits the bill as a winter bike. It’s not a ‘magic’ material, I just happen to like it.
EXACTLY!!! Glad 2 hear this. Ride what U like b/c U like it. OVERALL fitness is where your BIGGEST speed gains will be had. Adversely ‘older’ isn’t necessarily worse... but style most certainly plays a part in many choices. I am a sucker for polished metals and clear costed cf...🤗😬🥴
I’m the same, I bought my titanium bike because of its corrosion resistance and it looks nice as well not because of the so called carpet ride quality.
Enjoyed the science. I love my Ti mountain bike (Jones Spaceframe) and completely agree that the seat post and tires have the greatest influence on ride quality. The durability and maintenance of raw titanium is great, no paint to chip and easy to buff out scratches. Also the sound of rocks or gravel bouncing off the down tube is nicer than aluminum.
Now this is a reviewer that listens to the ‘community’! I love that you focus on quality over quantity. Looking forward to more videos to make the coming year easier. :)
Agreed, I own steel, Al, CF and Ti. The titanium bike convinced me that it is a superior material. Yes it is marginally heavier than my CF bike, but it handles hard bumps in the road much better. Also titanium is much more durable than any CF bike.
@Jeff R I agree, Titanium is a wonderful material for road, gravel, cross and touring bike frames. It's super expensive to build with, and requires absolute precision build quality. But has a great smooth and springy ride. It's not great for high torque frames like full suspension mountain bikes (too much lateral and torsional flex) and aero sprint road bikes (really tough to shape), but otherwise, it's great!
If I had to guess, it's because the average aluminium bike is much cheaper than the average titanium bike, so it's typically paired with cheaper wheels, cockpit, seatpost, and saddle. There's no point spending £2000 on a titanium frame only to put the same cheap finishing kit on it. Presumably the comfort of high-end wheels and compliant carbon seatposts/bars are often mistakenly attributed to the titanium frame. Plenty of reviewers, vloggers, and bloggers have done enough testing to confirm that tyre and tubes (or lack of tubes) make the lion's share of the difference to ride quality.
I never tried to sell a ti bike on material based ride quality, only durability, repairability, asthtetic, and the lack of corrosion. Thanks for the confirmation.
Hi, yes I had a Litespeed Classic (96) in a 57cm,was 1400gm .They do flex around the Bb when you stomp on them,to me they have similar ride qualities to steel but lighter. As you said the best thing about them is corrosion resistance and long fatigue life. Mine was a polished finish,so no paint chip problems,also the surface hardness is very good. This is 3/2.5 ti alloy which is 3% alu & 2.5% vanadium . The Litespeed Ultimate was 6/4 ti alloy ,has more complex shapes and is stiffer.
Interesting. My impression of modern bikes, including titanium frames, is that wider tires and modern geometry (slacker head tube angles) have made riding more comfortable on more surfaces. After 25 years of hard work, saving and learning what I like and don’t like, I chose a titanium frame partially because of what it meant to me as a trophy but mostly because of the impeccable build quality. As I’ve gotten older, I have less patience for things like noises and quirks and a titanium frame solved a lot of my complaints about mass production bikes. As they say, “to each, his own.”
This is all silly. Titanium or rather the frameset has almost nothing to do with this. It's wheels, tires, freehub, drivetrain, cable routing, and 2x vs 1x that matter far more.
I live in a region with a hot humid climate. Titanium is the only material that stands up to my sweat. That's enough reason for me. I have owned steel, almunium, and carbon as well. Yes, rinse my bikes after every ride and give them a full wash, weekly.
Unless you have a poorly sized press fit bottom bracket on your frame or a carbon frame delaminating/ water bottle bosses falling out etc. Carbon has lightweight and supple characteristics that are desirable, but how many mid 90s litespeed ti and steel frames still ride just like their first day vs only 5 year old carbon.
I've just bought a Ti bike and I love it! I bought it for a variety of reasons but mostly aesthetics and hopefully durability. Having changed from an Al frame of similar weight it does feel more comfortable but that could be down to several factors such as the Ti bike has dropped seat stays, carbon fibre seat post and it's running 25mm tyres instead of 23's. I can't compare my carbon fibre bike as that's a TT bike and a completely different beast. Of all the bikes I've ridden the Ti one is my favourite though.
I really appreciated having all the common opinions about frame materials brought together and analyzed, saved me a lot of thinking in an area I know little about, but hear about often.
@@Primoz.r Totally, I mean it's comical but 30 straight minutes of hambini acting like a child is a bit jarring. There is also the fact that he usually reviews faulty frames that people actually send to him because they are faulty in the first place. Nevertheless he's a good educator when he's serious
Last year I purchased a litespeed gravel. The main reason I chose the gravel was so I could have multiple wheel and tire combos. The biggest difference in ride quality comes from the tires. 25mm tire rides like a log wagon and the 47 mm tires feel much better. The 47mm tires are not as fast but at 60lpsi the ride quality is much more forgiving , traction is confidence inspiring and it looks awesome.
The design of the bike has more to do with the "feel" of the bike than materials used. Over the past few decades, I have been fortunate in having a wife who has been tolerant of my spending habits regarding bikes. So, I have had road bikes in steel, carbon, aluminum and titanium. I still have carbon and titanium road bikes in the garage. The titanium is still my go to bike for half and full centuries. The design and materials make it efficient and compliant, much more so than a bike of any other material or design. I understand your preoccupation with numbers, but would suggest long test rides are a better measure of bike feel.
But how will bike companies massively inflate the value of their products if they sell bikes based on facts and not bullshit from marketing from the cycling "journalist" industry
They almost all did by 10-15% "due to covid-related supply issues", which is layman's terms basically is translated from, more demand minus the same stock sizes equals more profit for the same effort.
I think most industries market their products with bulshit that most people don't understand. And bicycle prices also have a big problem caused by how the sport is funded, basically from sponsorship, making their marketing budget heavy on the price of the products. And it is such an old model that I question their ROI and if that money should be better spend otherwise.
They will inflate the value of their products by changing the wheel size and destandardizing all the parts so you can't get replacements parts after five years.
Don’t worry dude, you’ll love it. Even if it does not live up to the hype (I think it does) you have a sick looking bike, bragging rights, and your bike will last forever.
Thank you. I'm a relatively novice when it comes to biking but I have lots of experience with metals and structures. I never understood it when they said a ti bike is stiff yet somehow more forgiving. I still want a ti bike. Mostly for longevity.
Love the details you’ve put into this video. Keep them coming. I will say though, you’ve essentially just described why all of these myths are usually true, just not for the reasons that are usually claimed. We ride bikes we don’t just ride aluminum or steel or ti as a stand alone material. As you described the different ways these materials tend to be constructed is what leads riders to say they feel one way or another. Their observations are valid even of the don’t know exactly why they are feeling that. I love that you pointed out the difference that components will make to the the feel of a bike because it is huge. We don’t ride frames by themselves after all haha. And as you mentioned different frames of the same materials can feel drastically different.
Agreed, the Ti ride is no better than a steel bike. Glad you corrected yourself in the pinned comment. No amount of quoting technical terms - can hide that you missed crucial data. The simple fact is that ali frames have to be made stiffer - as they can handle far less flex. Stronger materials like heat treated-steel (e.g. 853) - are usually built to make more comfortable bikes with more flex - as the frame can take that flex repeatedly without failing. Standard cro-mo steel cannot do that. So yes, with young's modulus, you could, in theory, build a bike out of the same types of steel - with all the same wall thickness etc. But the lower grade steel would not be able to take the flex, esp. if it was an mtb with a heavy rider for example. Sorry, but your original video just missed the key points - and hide it in a lot of tech terms that made it sound like you knew what you were talking about. One can feel a quality steel frame flex as put on the power. Frames do flex! Agreed the seatpost often makes the most difference. Esp. a cheap compared to an expensive one. But frames matter too. Over the past three decades, I have built up and ridden many.
As I have gotten older I have come to desire comfort above other things on a bike. It's definitely true that the industries recent shift toward fatter tyres has had a far more significant impact on general ride comfort than frame materials.
Thanks for confirming what I've always thought and experienced about what gives you comfort. Wider tyres with lower pressure and in my opinion, also a 27.2mm round seat post since tube diameter is also a contributing factor. Been running 22m Continental GP4000 tyres at 120psi for years and was shocked at what a big difference I experienced when I first rode on 25mm tyres at 90 - 100PSI.
You are absolutely right, my 1998 Litespeed Vortex at 1280 grams of relatively small diameter tubing and 1" fork steerer had the magical flying carpet legendary Titanium ride, my 2019 custom titanium frame at 1650 grams with big tapered head tube (1 1/8 - 1 1/2), and a 42mm downtube feels a lot like a stiff modern carbon frame that weighs 1000 grams...
Thanks for doing this video. To me the construction of the fork and it's inherent flex and and the tire sizes and pressures used make the most difference, especially when when a long and flexible seat post is not part of the equation. One can see fork and tire flex when riding. I have high end carbon, titanium, aluminum and steel road bikes made from 1971 to 2008. The material makes almost zero difference to the ride quality for me, but what is noticeable is the sound the bikes have when hitting bumps. Let's face it, brands have to sell new bikes and they have come up with marketing "facts" to sell them. For me, my go to everyday bike is a 1994 Litespeed, as the durability of it the best and there is no paint to scratch or corrosion to worry about and I still do PR's on it.
Thanks for that! I recently destroyed my 1550g Al gravel frame, and replaced it with a 2050g Ti frame, swapping all the components over (group/wheels/bars/etc), and noticed that the Ti frame has less "chatter" from the trail. If I'm understanding your comments correctly, this is likely to be an artifact of the increased weight of the frame (and potentially a different seatpost)? Cheers
I ride many (6) different Titanium Bikes and there are huge differences in the ride feel between them. A REWEL with a seat stay shaped like a Pinarello feels like a fully. A MORATI with a straight seat stay rides like a KLEIN. The main reason why I have Titanium Bikes is not because of the magic carpet BS but the durability and the look.
There are certain characteristics for each materials, to where they are built differently. Strength to weight ratio, weight/thickness to stiffness ratio etc.. Crunching numbers to justify the "The same" argument is kind of asinine. I mean in that sense anything can be made equal.
Great piece. Despite it not being the "wonder material" overall, it does have one other advantage not mentioned. It's extremely durable, i.e., resistant to dings and dents. Aluminum and carbon are susceptible to dents and chips respectively. It's certainly a lifetime material where as aluminum and carbon are not. But now I have more to chew on in my search for a new gravel bike. So, thanks for making my choice more difficult! 😉 👍
There’s myths out there about aluminum as well. The assumption that stress accumulates over time leading to inevitable breakage for example. Doesn’t seem to be the case with bicycles. I’ve had 3 aluminum bikes for 15+ years, no chips, no dents, all signs are they will last as long as steel…
Carbon frames become flexier with time compared to Ti steel or aluminum so I would say Ti is superior if you look at companies like Moots there superior
Youngs modulus and corrosion resistance were the two specifics I was wondering about. Thank you for the in-depth answer that so many skip over! I love my 20 year old Aluminum Specialized Allez but it seems like no one has found a good way to make paint to stick to Aluminum for more than 20 years or so.
I think most people mix up the great feeling of their first custom bike (if their builder was good) with it being a magical property of Ti. All down to the quality of the builder and their understanding your needs, or not for mass produced bikes.
Your right ,I got some in 25mm but they measure 27mm .....they feel great, comfortable, and feel super fast 👌I had veloflex corsa in 25mm before which were not good at all!!! Lots of punctures, the ride quality was awful even with latex inner tubes in 🤷♂️ they have improved there tyre line up now
Thanks PT great informative videos based on engineering realities, refreshing alternative to those marketing unicorns. Hugely enjoyable and always interesting seeing the wide variety of views they elicit. For riders thinking of a change of frame material ...... IMHO test as many bikes as possible by actually riding them and remembering .....(1) wheel build/ tyres/ seat post have significant impact on noticeable feel ....(2) Everyone has their own subjective arse. 😇. So ride it because you like it. 😁
Just found this video. I have my first ever titanium bike. I love the ride, sure, but as a mechanical engineer, I was pretty skeptical about the "magic ride" claims. And a year after owning it, no there is no magic ride. However, it made a lot of sense for a mountain bike due to the fact that I don't have to worry about paint chipping and rust. I think people convince themselves that titanium has a superior ride due to the high price, the rarity, the name, and the fact that there is a popular song named after it. As far as ride quality, I find that I still prefer high-end steel. I think it's because of the ultra-thin tubing walls, which make for a nice resonance and sound that I don't get from other materials.
I have a Dolan titanium ADX frame and it is beautiful to look at, but I agree that a carbon seatpost is huge when it comes to this. I watched one of your older videos where you talked about the cheapo FSA handlebar. I bought one for about 30 euros and it is amazing, I love it!
Thank you. This clip earned you my sub. My experience is that people should look for frames that accommodate wider tires (at least 28c), when looking for comfort and speed rather than specific material.
Great work on this. Nice to see someone finally trying to debunk some of the misconceptions that I have to try and educate people on daily. As someone who has designed frames in all of the materials you mention, but who works mainly in steel now I think the one area that is ripe for further content is the impact of tube size, shape and butt profile. One of the reasons Titanium has never really lived up to its promise is the difficulty of tube manipulation, unlike in steel or Aluminium. Id be interested to hear your thoughts. Maybe we should build two steel frames of the same mass but with different tube profiles and see if you can tell the difference...
My mountain bike and road bike are Ti, for the simple reason that I wanted a "lifetime" frame (basically I wanted it to be the last frame I ever bought etc...). I'm 99% sure that I actually hadn't given thought to stiffness or ride quality. As a Gen X'er, I just think Ti was that bad ass super alloy that was part of the space race. Growing up during the middle of the cold war, the X-15 and SR-71 was mind blowing, as such Ti was just that cool exotic material. I just bought Ti cause it just looked cool and it was the material that made amazing things happen when I was a kid. IMHO, if someone is obsessed with performance figures and wants the latest and greatest, they should just by the latest and greatest Al frame every other year (or a carbon frame if you've got deep pockets).
This is a late comment, but this is my exact thoughts on titanium frames. A good quality Ti frame can definitely be a lifetime ride, which is why I just spent $7k on Pilot Cycles Scram Pinion bike. It’s a lot of money, but it should last me my entire life! I’m not too stressed about ride quality, I just wanted that titanium “look” and durability.
Carbon frames to me are not durable at all. I think Al frames are still pretty damn durable. I still ride a Caad7 from 2003 that has a LOT of miles on it and it still works great, shows no sign of wear (has a dent on the main tube from a crash, which would have meant the end of the frame if it was carbon). That was my grandfather's bike, my bike is a 2018 specialized allez sprint comp because it was by far the best value bike on the market at the time. I expect it to last a really long time, even though it's an Al frame. Titanium is ideal, I agree, but way out of budget. I don't understand why people think Al doesn't last long, it easily can last 20-30 years.
I like the springy side-to-side flex at the BB. Makes climbing hurt my joints (e.g. knees) less, and makes my heart the limiter rather than the body. The frame gives, instead of my joints, and that flex is returned to the drivetrain as propulsion (see GCN "are you faster on a stiffer bike" vid) during my dead stroke. That's the smoothness I feel. Feels like steel tubing consistently gets the just-right amount of flex that I've grown accustomed to.
If you want a source to look at ride comfort you should look into the research in titanium vs aluminum wheel chairs since it's a medical device they did serious research on it. The findings where that aluminum is a better vibration dampening material but the difference is only noticable in instrumentation. When they tested it with people there was no difference in feel. However separating the parts with polymer materials acted as vibration dampening for the chair. I suspect the better feel is from the fact that usually titanium bikes use more carbon parts than aluminum bikes and the carbon is responsible for the vibration dampening.
I had an aluminium fork on my steel gravel bike and recently changed to a Enve Carbon fork and I find the carbon fork much hasher. Go figure. Nothing else changed so I don't know what to believe
HSS actually has a specific modulus similar to aluminium and titanium. Al frames can be built lighter than steel. The torsional stiffness of a bike frame is basically determined by the GJ of the top tube and down tube, and this is mostly controlled tube diameter. For the same amount of material, the linear static theory tells you it is better to distribute it on as large a diameter as possible. This breaks down at the point where the tube is so thin that it is at risk of shell buckling, and this tends to happen at a fixed thickness/diameter ratio. Aluminium is much less dense than steel, which means a given sectional density can produce much larger diameter tubes before buckling. For the same reason, optimally designed Al frames will be lighter than Ti frames. I work in composite structures, and there are some specific applications where balsa wood or styrofoam produce stiffer and stronger structures than carbon fiber at the same weight, for basically the same reason.
Don't be put off by this, its good explanation of why some of the marketing from bike manufacturers (and marketing in general) should be taken with a grain of salt, but speak to some Ti owners who have ridden other materials at similar price points/levels. There is a reason the vast majority of us end up preferring Ti that can't be quantified by simply looking at material properties.
My input, I have 2 steel Pegorretti’s, A steel Salsa and a Moots RSL, I have had a carbon tarmac and 2 Aluminum frames, so I feel like I have pretty good experience. If I had to choose just one it would be the Moots hands down! Now don’t get my wrong, as you can see, I love steel bikes, but I look at the Moots as a Swiss Army knife, it does it all well and doesn’t rust! Edit- so I just got a steel gravel bike, it has 38c tires MASSIVE difference, talk about frames all you want but big supple tires rock!
My thoughts as well. I have a vintage steel fleet, an aluminium framed gravel bike and a vintage carbon bike. Wheels, tires and tire pressure make the most difference to the ride quality. I use hand built wheels as well which also improves ride quality and performance. I can say this without any doubt. So while frame material is part of the ride quality equation it’s not the whole answer.
@@finarollerz Frame is a starting point. If it was the only thing folks would never upgrade wheels, tires handlebar tape and so on. Case study, hi mod carbon frame on 23mm tires and mavic wheels vs 26mm rubber at lower pressure on wider custom wheels is a night and day experience in ride quality and handling. Same frame. And same deal across all the bikes. Frame is a starting point. Much better with better wheels and tires.
People want to feel unique but part of a group at the same time. People underestimate how many of their choices will be influenced by the predominance of one over the other and the "noise" created by marketing. "Buy titanium. You will be uniquely different !" "Buy carbon. You will be part of the elite" "Buy aluminum. You will be part of the performers that are Savvy with their money and you will be different" The funny thing is that very few people buy a product based on their real needs/use case and their physical attributes/performance level. Generally speaking, as George Carlin said : "people buy things they don't need at a price they can't pay to impress people they don't like."
I went from custom 32mm dt swiss aluminum rims with dt swiss aero comp spokes on hope rs4 straight pull hubs to 60mm prime black edition carbon rims with the same spokes and hubs and the ride quality is better , but I did change from gp4000 28mm to 26mm specialized turbo tires as well so maybe they were making a huge difference. 😃,overall though they feel way smoother than the aluminum rims.
@@MrGarycoww ... Bianchi has been using vibration damping technology in their frames for a while now. Have a look. ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-2WlrUYjOBNg.html
@@MrGarycoww ... Similar but different in that with the Contervail system the vibration damping is built into the adhesive and a layer of specail composite, so it would be ideal for composite rims. www.compositesworld.com/articles/countervail-vibration-canceling-composite-technology
Hi it's a great video thank you. Currently I am having an Aluminum Bianchi Freccia Celeste road bike with Shimano 105 group set and rim brakes. It's performing well and I like it. however I am looking for a Ti for my second bike, I just need to know from you does TI material 3AL/2.5V durability in the long run is the same as 6Al/4V? Or having a 3AL/2.5V bike with only the top tube made from 6AL/4V ok? And finally the Litespeed bike that you showed in the video, the seat stays does not have a bridge on top (similar to a rim brake bike where the rim brake caliper is fixed this is the are I am referring to as a bridge) by not having this bridge on the seat stays will there be additional stress to the seat stays? Appreciate your answers very much in this regard.
What about specific Strength? (not to be confused with Stiffness) Giving the smaller second moment of area of Ti tubing most likely means the maximum distance from the centroid will also be less hence less stress for the same given bending load, combined that with the higher material yield strength of Ti means a Ti tubing will have higher strength and larger deformation at failure compare to one made from Al. Translate this into bike frame design, yes you CAN design a AL and a Ti frame that has the same stiffness, Ti CAN however allow for less stiffness (more compliance/comfort in marketing terms) for a giving strength requirement and that is desirable if comfort is what you want to maximize. Nevertheless, You can of course get a comfortable Al or a harsh Ti frame, other factors are also important.
Enjoying you channel and the fresh analysis of riding position. I’m tall at 193cm; all leg. Messing around, I feel way better coming forward with my saddle but I struggle with weight on my hands. Do you find your saddle height needs to go up considerably compared to the recommended position? So to be balanced without too much weight on your hands? I find tall, longed legged riders don’t fit any fitting algorithms. I’ll be interested in a post re your own bike fit. Thanks!
Since the main bulk of the comfort or compliance comes from the seatpost, how would a Ti-Carbon bike feel then? Ex: Bastion or Curve Belgie Air. They're marketed as combining the best of both worlds but would we just be getting a Ti bike that has it's compliance ruined by the stiff carbon that's been added into the mix? What do you think?
First of all, thanks for the great content ! Most of the time stiffness (especially in the bottom bracket area) is advertised a key factor in bicycle performance. However some people contest this vision and even state that some lateral compliance is beneficial for performance for the vast majority of cyclists (some guys in a magazine even talked about "planning" to name the characteristic of lesser stiff frames deflecting along with pedal strokes). As a guy with no engineering background I can't seem to wrap my head around this question as I found mostly unsupported claims, or dubious marketing statements. So, is lateral stiffness around BB a key factor for performance ? And to which extent ? If this subject is addressed in one of your video (or elsewhere) I would be really eager to have these informations. Cheers !
Thanks for being a fresh voice in the clutter of bike marketing :) You are doing the community a service by making basic engineering easy to understand and give the consumer some tools to weed out the bs marketing. So, keep up the good work (it isn't work if you luv doing it ;)) and don't look to much at the comments...for some it will never be 100% ✌
Top class nerdery there m'boy! Couldn't understand it, but love it. I've a custom made Ti frame - it's fabulous, but you're right, the magic carpet ride comes from 26mm Turbo Cottons with latex tubes, not Ti tubes. Nice Litespeed though.
You’re exactly right that the impact of frames and frame material on ride quality often is overstated. Your choice of wheels/tires, fork, and seat post/saddle likely will have as much or more of an impact on ride quality. That said, titanium is very light and very strong, both of which are good qualities to have in a bike frame.
Hey I see you're good at FEM analysis, could you do a vibration/modal analysis of different frame types ie dropped/ normal stays and different materials ie alu and Ti thatd maybe help dispell some of the myths around material and show that it is more dependent on geometry/tubing
@@PeakTorque yeah its fairly time intensive, I've thankfully already got a frame designed using standard round tubing with no butting and standard seat stays made from steel on ABAQUS. I would need to change the materials and design a dropped seat stay version and run simualtions for each iteration. I could post the results after I've finished exams and had the time to do it
@@PeakTorque what calculator app are you using on your smartphone? Thanks for posting a video with some real engineering justifications vs pseudoscience and buzzwords.
Thank you for this enlightening video. At the end you say your frame is too light for your height and weight. Could you explain again which "ratio" is the right one? Maybe it corresponds to the other marketing race at the lightest?
Hi, great video. Have you made anything regarding the virtues of bicycle frame stiffness? Particularly with regard to the overall efficiency of torque transfer from chainring to wheel over a number of revolutions, I would be very interested to know whether a less stiff frame material resulted in any net power losses.
Great video, informative and well structured. Audio was also nice and uniform ;-) I do have a thought to share, a question left to answer, though. With Ti having more strength and being the denser material than Al, one would need to construct a frame out of tubes that are either scaled down (in the cross-section, not length ofc) or have thinner walls. (or combination in between, whatever) That way the resulting trusts has about the same strength and mass. But wouldn't those smaller tubes make the frame more flexible/less stiff in bending around the longitudinal as well as the vertical axis?
I hope this is understandable. I am neither a mechanical engineer. Only sat in "Mechanik 1" course, because every student in Germany has to have heard Mechanik 1 at some point! :-) Yeah... Electrical engineering and I quit
Love my 2004 Litespeed Tuscany, as it fits me so well. I understand the Young’s Modulus and shape argument . This is born out by simply replacing the 21 mm tyres with a 25 mm tyres or changing out the wheels.....they make a huge difference to the ride quality on the same frame . Still, we don’t want to get into a digital vs analogue music argument then do we :)
Tyres, wheel seat post, handle bars all affect the compliance/ comfort of the a bike. The trouble is now disc brakes accept wide tyres so they can be supplied to the “influencers “ in a spec to make the characteristics fit the press release. Modern disc bikes have all the equipment to make them compliant flexing seat posts, carbon one piece bars and shallow wheels. If you pop 60 deep section wheels, 23 mm tyres, alloy post and bars you’ll see how harsh a modern disc frame is.
Yep, my 2003 Airborne with 25mm and 2014 Ultegra 6800 was a nice step up from the 03 version, but doesn't hold a candle to the upgrade to my 2020 T-Lab. Unique tube shapes make for a very stiff front triangle, with the rear triangle having that all familiar ti ride.
Finally! You confirmed what I thought I knew already from my own practical experience. I travel with a Titanium bike because it is indestructible. I have a CAAD 10 for the same reason. Both metals are ok for stiffness and comfort. I like the naked Titanium look. But that’s it. And it’s enough. Thanks for this and other videos like it.
Hi there. I've watched this video several times. I like the content. I love titanium bikes. I always wanted one as much o wanted a carbon bike back in the days when I was younger. Now I own a full carbon bike. But after seeing watching this, I will definitely build my aluminum frame /carbon fork up. I will build it with DA 7800. I will try to build a sub 8kg bike. Thanks for sharing man.
The "zingy carbon frame" thing is also marketing BS, with composites you can have whatever you want by changing the fibre orientation, material type, etc.
Well...exactly? You're correct that a frame being made of carbon fibre composites doesn't inherently make it 'zingy', but the use of those materials allows a capable engineer to create a stiffer and lighter frame than they might with other materials, i.e. 'zingy'. It's only marketing BS if it's a poorly engineered frame.
@@ccmmrrnn what I am saying is that there is nothing to stop you designing a nice soft and lightweight carbon frame, a really stiff one or anything in between.
Great video! I've always wanted a Titanium frame ever since my cousin got a Merlin back in the 90s - it just looked so incredibly beautiful and was so lightweight but also agile? Nimble on its toes and responsive! I guess that is what we could call stiffness? (I always get confused by what people mean). There's also the huge appeal of custom geometry and fit - that's the main appeal for me really. Having a Titanium bike built in America or Italy though (as opposed to a much cheaper Asian build) isn't an option, so the next best option for me then is good old steel. It's great to watch this video and understand that a metal frame with similar tubing layout and weight is going to result in a frame that is more or less the same in "stiffness" to titanium. A custom steel frame will have all the same simplicity and aesthetic qualities as titanium, but will be cheaper than a quality Titanium equivalent. I've been sat on the fence for ages, and I think this video just made my mind up so thanks!
Enjoyed the video. I am also a larger rider (250+ lbs). I notice the bottom bracket moving laterally quite a bit when I rally push hard on the peddles. I imagine that movement results in a loss of power transfer to the drive train. How power is lost and is there an optimum frame geometry and material for high torque applications? I have measured over 1,000 ft/lbs of torque (Garmin Vector 2) on some of my sprints.
I would love to see a follow up on the impact of hydroforming aluminium when both main factors are constant, in terms of stiffness in certain axes vs. compliance in others
@@timocallaghan4408 The idea is not new. You want rigidity in the lateral dimension but flex in the vertical dimension. There are a few ways to accomplish this by changing tube shapes. Much of this has already been fleshed out by all the major fabricators. I wouldn't worry about rehashing it all over again.
@@timocallaghan4408 Hydroforming is just a fancy way of shaping tubes. Do you want to learn about hydroforming? Altering tube shapes from a circular cross-section to an elliptical one is what gives the desired characteristics.
I think this is simplyfied way to much. As far as I remember from my engineering studies, I scales with the power of 4 of radius of a tube. Weight scales linearly. (Thats why bikes are made of tubes and not rods) Since risk of crimping puts a limit on wall thickness, aluminium can be used to make a lighter tube of equal stiffness to that of a titanium one. To make a fair comparison I think you need to compare the value of the square root of E divided by density, for each material.
Nice video, I'm glad youtube recommended to me.. I have a question.. If Ti is marketed as buttery smooth it means it is more compliant? Which means it is less stiff? So then why would you want a stiffer frame? Do people prefer stiffer frame or compliance from Ti? I mean in the marketing terms..
They look cool polished, they don't corrode and can be easily recycled, that's about it. Like he says, the material doesn't matter too much, it's the shape of the tubes and bike geometry.
What’s the big difference between titanium and other bike frame materials? Other cyclists will admire your titanium bike over any other bike. The drooling factor should not be underestimated 😆😆😏
He ain't lying. I picked up an old litespeed ultimate with a polished finish for cheap 2 years back and it gets way more comments and interest from bikey people than a mid 90s frame would seem to deserve
Newbie:- is that carbon Me:- No it’s Titanium Newbie:- Ooooh 😳 …… Expert:- Titanium you say? Me:- Yes. Expert:- it’s lovely, how’s it ride?? Me:- It lovely, really smooths out the trail. *quickly deletes RU-vid history
When I raced mountain bike in Alaska in the 90s, one of the strongest road riders around was a cross country skier who only raced road in the summer as off season training and he used to crush everyone on an ancient 60s bike with cotter pin cranks. It was a hunk of junk, but the motor was faster than everyone else’s. Todd Montalbo was his name (I feel like I should be using the voice of the tackle shop owner in the Simpsons that told tall tales about Homer Simpson catching General Sherman, the biggest fish in the lake).
Agree with all you said , & great to see proper engineering basis vz seat of pants opinions around frames...keep it coming ! From my experience 'Durability' and 'fatigue resistance' are also tricky terms given how many factors affect them beyond the base material properties, - I've had two TI frame failures with cracks & two carbon frames badly deteriorated with alloy corrosion leaching into carbon at 'joints'
IF that alloy leaching was a problem, just imagine what will happen when those (soon to be the only way carbon bikes will be sold, if the manufacturer trends keep up like they are) all internal brake lines filled with corrosive brake fluid start leaking into those same carbon frames, even if they are internally gel coated (I'm guessing most are not, anyway??). The sharp bends required to be hidden internally, especially near the head tube/stem even help contribute to the brake lines cracking, wearing through, and rupturing. :( NOT a good design, in my honest opinion at least.
You can probably make that frame bit more comfy buy having curved seat stays instead of straight so you can let the chainstay flex more, plus curved front forks instead of straight.
Given the same steering tube angle and relative position of the axle to the crown, a straight blade fork can be made to flex as much as a fork with curved blades. the flex will be more up at the crown itself, and the force from the road bump through the wheel axle to the fork will have a longer lever arm to flex the larger section crown, while in curved blade forks the flex will occurs more at the lower end of the fork, where there is less cross sectional area but also much less of a lever arm. Don’t get me wrong; I prefer the aesthetics of a curved bladed fork, especially a steel one with a lugged crown, but that’s because I’m an old retro-grouch.
Interestingly, the specific modulus of steel is also basically the same as that of Ti and Al (and magnesium is right in the same ballpark, too). (Also, note that, unlike strength, the modulus of elasticity is essentially the same for different alloys, heat treatments, etc.)
It’s BS. The big advantage of steel is that it’s easier to work with, especially for a small custom builder, so you can get exactly the geometry you want. It’s also much better for custom forks. If you’re like me and enjoy riding low-trail frames, steel is the only way you can get that. Ok, steel fork with a Ti frame would work, too. But other than that, damping is the same for both (nonexistent) and springiness is essentially the same.
BS that has been spoon fed to consumers of boutique steel and ti frames for decades, and has now trickled down to the non boutique steel frame consumers. Same BS as the “springy smooth” titanium ride BS claims. Reminds me of all the goofballs, who claimed their silly priced Pegoretti Marcellos and Big Leg Emma's were smooth riding because they were made of steel. Some of the stiffest and most bone jarring frames ever made. Boonen rode one to his TDF Green jersey win in 2007, and even he conceded it was an incredibly harsh riding frame, but great for the sprints. People easily programmed by marketing BS will regurgitate any nonsense spoon fed to them that makes them feel warm and fuzzy about their purchase decisions. Happens in almost every industry. 😆
Having watched a number of club mates and friends buy Ti bikes and it's usually in their later (and post-racing) years. I've noticed a trend, that the Ti bikes tend to be more comfort oriented (longer stays, longer exposed seatpost, larger tires). They ride for a while and expound on how comfortable the Ti bike is... buddy it's not the frame, it's the 32c tires.
