It is COMPLETELY noticable. I'm guessing you've never ridden a carbon bike before? It's like an extra damping circuit that every other force has to travel through. Yet it's so much stiffer noticeably, it's an amazing feeling.
Carbon V10
- Thread starter altix
- Start date
im gonna have to side with the majority. carbon and steel feel completely different than aluminum
Its hard to compare two idential bikes, one in carbon and one in AL. It was pretty obvious when I went from Al to Carbon on my XC bike (BLT2) going from after I breaking the AL frame.
I won't say I could tell on a big hit, but on washboard/higher frequency type stuff it was really obvious.
I won't say I could tell on a big hit, but on washboard/higher frequency type stuff it was really obvious.
lol wut?
That bag must be a PITA to get out. Looks like the head tube is a secondary bond so maybe they get the bag /peel etc out then chuck the HT on??
Can't avoid those creases unless you make a really nice bag eh. Not ideal but there is that many layers on that thing I doubt it would matter anyway.
Can't avoid those creases unless you make a really nice bag eh. Not ideal but there is that many layers on that thing I doubt it would matter anyway.
Agreed. I've tested several carbon bikes. The Trek Fuel EX 9.8 for a trail ride, an SW Epic for good XC loop have tried out the mojo as well. I've noticed the frame stiffness under pedaling as the primary difference from the comparable alloy bike. The SW Epic was amazingly responsive in that regard, it tracked really well.
This damping effect would seem to be pretty limited in a DH bike due to tires and suspension as mentioned earlier, but in a HT, maybe its more noticeable
thats not the point.
of course they have very different feelings... but one thing is a rigid road bike with 100psi skinny tires, and a dh bike with 2.5" tires and 10" of suspension is another.
people can tell the difference with 10" of suspension and fat tire to deform in between, or its just the kool aid talking?
can they feel a pea under 6 mattreses?
if you wrap 2 baseball bats in 5" thick latex and hit a ball twice, can they tell which bat is stiffer?
Last edited:
Different components (suspension, tire, frame) dampen out different frequency ranges. As someone mentioned, a carbon frame may dampen out high frequencies. Can't imagine this affects performance in any way, but it could definitely potentially affect feel at the handlebars.
that IS the point. there is a noticeable difference b/w all materials regardless of the amount of suspension and or size of the tires.
it seems you are the only one who thinks otherwise
The difference is noticeable on a road bike. It's VERY slight on an XC hardtail. It is not in any way noticeable in terms of "vibration damping" on a downhill bike, that's actually hilarious that anyone would try to pretend that it is. You might honestly believe that it is, but I can assure you it is a placebo. The vibration frequencies at which carbon has superior damping qualities to aluminium are FAR higher than the natural frequencies of the tyres or the suspension on a DH bike (talking like 30-40x higher!). Vibration transmissibility is a function of the ratio of input frequency to natural frequency; as input frequency gets higher relative to the natural frequency, the transmissibility drops asymptotically towards zero. On a road bike, the input frequencies to the frame can be high enough to feel a difference in compliance and damping between aluminium and carbon, the same is absolutely NOT true on a downhill bike, especially given that downhill frames are NEVER built for vertical compliance via flex - again unlike road bikes. Just total BS, like the claims that Ti springs are somehow more supple than steel springs... just people wanting to further justify the fact that they spent a lot of money on a bike.
hehe
yeah when i think about carbon, i always see weight savings.. how about 10kg DH rig?
But have you ridden a carbon DH bike? To experimentally prove this?
I have not.
But the human body is an amazing thing. I don't like to underestimate it. Is it the placebo effect? Possibly. But maybe not.Should have asked Peaty last weekend...
EDIT: I don't know why I'm arguing this point...doesn't make a hill of beans difference...
It's a noticeable difference on my XC bike (SC Tallboy) and I have ridden Commencal Meta 55 Alu/Carbon frames back to back with the same parts and it feels quite different. My Fury doesn't seem to smooth the ride as much but it is layed up quite differently than the SC bikes.
Yep, ridden two of the ~15 Lahars in existence, amazing bikes. I don't question that it's stronger or stiffer (in fact, particularly on an XC bike I'd entirely believe you could feel the difference in stiffness, just not the vibration damping thing everyone harps on about), but the "feel" of carbon thing is exactly the same as the whole steel roadie/XC hardtail thing - yes there is a noticeable difference when your total "suspension" from frame and tyres combined is measured in single digit millimetres, not when you have 2.5" of soft compound rubber at 25psi backed up by a further 10" of travel!But have you ridden a carbon DH bike? To experimentally prove this?
I have not.
Should have asked Peaty last weekend...
EDIT: I don't know why I'm arguing this point...doesn't make a hill of beans difference...
I agree with whatever DW says.
Not sure why, but I am surprised to hear you say this.
It is not placebo, not someone trying to justify the cost, etc. Metals and polymers behave differently. The nature of the material results in vibration deadening. There is a very noticeable difference, even with lots of travel and squishy tires.
If you can't notice the difference, you can probably ride pretty much any bike out there and stop enginerding everything.
It helps to ride the carbon and aluminum bikes back-to-back, but that isn't even really necessary.
The bottom line is, whether you can feel the high frequency vibration damping or not, it's not gonna make the bike any faster or give it any more traction. So it's a moot point.
Kind of like all this low center of gravity business. Yes, it makes the "steering" weight (actually roll moment) a bit lighter when flicking things around, but it doesn't really make the bike any faster or corner any harder. Just a matter of preference. (And as a side note, in the car world light steering = buick, heavy steering = BMW.)
In fact, one might ask why one would want all that weight at their feet when they could have it closer to their body's CoG?
But I digress.
Kind of like all this low center of gravity business. Yes, it makes the "steering" weight (actually roll moment) a bit lighter when flicking things around, but it doesn't really make the bike any faster or corner any harder. Just a matter of preference. (And as a side note, in the car world light steering = buick, heavy steering = BMW.)
In fact, one might ask why one would want all that weight at their feet when they could have it closer to their body's CoG?
But I digress.
There is SO MUCH that actually measurably and noticeably affects vibration transmissibility through a bike and rider (just so you know, I wrote my thesis on the transmission of vibrations through bike and rider, this isn't something I've spent 20 seconds thinking about) that makes a far, far bigger difference to the harshness you feel, than the vertical compliance of carbon fibre structures as compared to aluminium ones. Suspension characteristics, tyre pressure, tyre compound and tyre size are the big ones.
But if you really want to look at high frequency inputs to the front triangle of a bike (caused by such things as oscillation within a spring), carbon structures, being typically STIFFER than aluminium ones, have a higher natural frequency. Vibration inputs below about 1.4x the natural frequency of any mass-spring-damper setup will net a transmissibility ratio of more than 1, and above 1.4x the natural frequency the transmissibility will be below 1 (ie force and displacement transferred to the sprung mass will be less than the input). The natural frequency of DH bike suspension ranges, from memory, between 1.2-2.5Hz depending on setup. The natural frequency of, say, a swingarm on a DH bike, is going to be in the range of 30-150Hz (estimating here) depending on how it's constructed. Have you ever seen any kind of input above even 30Hz of any significant size? Think about it - have you ever seen your suspension move up and down 30 times in 1 second? Nope - tyres iron that stuff out. Mechanical suspension typically deals with stuff from 0.5 up to 15-20Hz. Below 0.6Hz or so your body can actively compensate for almost any input, to the point where the bike's reaction isn't actually predictable as it's dependent almost entirely on the rider's reaction.
As an easily accessible example of how input frequency affects what you feel, roll your bike down the street slowly (walking pace, 5km/h or so) and notice the distinct buzzing you get through the bars from the knobs on the tyres. Try it again at say 40km/h and see how much of the tyre vibration you can feel - for me, only the very faintest. Forcing frequency is significantly above the natural frequency of the tyre at that point, nothing is even getting through to the suspension (can feel this effect even on a fully rigid bike).
Anyway whatever - I'm a fan of carbon fibre bikes because I like the fact that they CAN be stronger, stiffer and lighter. If you honestly believe that it feels smoother over bumps too then great, as long as you love riding your bike then that's all that really matters. Hell, buy a $5000 bike just to hang it on the wall and stare at its awesomeness for all I care, nobody has to justify what they spend their money on to anyone else!
Last edited:
Ive been reading the whole argument and we should end it at that. I agree with socket on it, though I have far lesser knowledge. Everyone told me my carbon bar is what makes my hands/arms less tired than my friends but suprise suprise - went to a 7075 flat bar and Ive noticed no differance. I like the material for the same reason Socket does, though Id rather try the fury over v10. Just like the susp idea more (the price a bit less
).Gasp! A plot twist in all this sillyness!
You are obviously very knowledgeable. I can't compete with some of your technical language and won't try.
Sure, for the same material, a stiffer structure will ordinarily have more vibration. But we are talking about different materials, with different physical properties. Did your thesis include a comparison of metals vs. polymers?
Metals act like a spring, with no damper, so they vibrate more. Polymers do both, and with built in damping, they vibrate less. You don't have to believe me, but it's true.
Anyway, I've made my points, the horse is long dead.
This is true.Sure, for the same material, a stiffer structure will ordinarily have more vibration. But we are talking about different materials, with different physical properties. Did your thesis include a comparison of metals vs. polymers?
Metals act like a spring, with no damper, so they vibrate more. Polymers do both, and with built in damping, they vibrate less. You don't have to believe me, but it's true.
Anyway, I've made my points, the horse is still breathing a bit.
And while I also agree with the majority of what Socket has said, a composite structure doesnt have to be stiffer than aluminium. The very nature of carbon composites is that it has different material properties in different orientations. Dramatically so in fact. To such a degree that with clever laminate design you can tailor them to your needs. You could make a structure like a bike frame hugely stiffer that an alloy one in one direction while at the same time being much more elastic in another This would translate to a totally different feel to that of an alloy frame in the real world.
the flex leaf stays of the lahar are neat in that regard - it's as laterally stiff as anything i've felt, yet they flex up and down ~2" in lieu of a pivot. cool stuff.
Great discussion Socket but I'm curious about imputs into the frame with large components perpendicular to the direction the suspension opperates?
Surely over the course of a long run there should be plenty of these types of hits to feel them?
Surely over the course of a long run there should be plenty of these types of hits to feel them?
This is an EXTREMELY complicated topic, and we are discussing in a few hundred words what usually takes entire textbooks to accurately describe. All materials have some degree of what's called material damping - that is, if you induce free vibration, they will not vibrate forever. Carbon fibre reinforced polymers (CFRP) typically have a fairly large degree of material damping compared to metals (which, make no mistake, are not "undamped", just not as heavily damped as CF), however what a lot of people miss is that a lot of vibrational input, especially when it comes to suspension, does not actually involve any of the oscillation that people typically associate with the term "vibration". Vibration on its own is a term used to describe displacement of a mass that has some kind of restoring force acting against the displacement, in other words, you push an object in a certain direction, but there is something (other than the inertia due to the object's mass) acting to resist you, and those components are broken down into what we refer to as "spring" and "damping". For the greatest part, spring rate is what varies the most significantly (think 3" XC bike vs 10" DH bike), and essentially it is the "spring rate" of the structures that makes the most significant difference to what a rider feels in terms of harshness - in my opinion, at least. For example, if you make a handlebar less stiff, it will transmit less harshness (less stiff = lower natural frequency, as I mentioned previously) to the rider, regardless of its supposed "damping" qualities. What a human rider feels as harshness is not actually oscillatory motion of the structure of the bike frame, which IS significantly affected by the material damping qualities, but singular inputs whose frequencies can only be accurately described by means of power spectral density (PSD) graphs - that is, to take a FFT (fast Fourier transform) of the motion of the sprung mass (again in this case the front triangle of the bike) and observe which frequencies occur most powerfully. Usually there will be a few notable frequencies which coincide with the damped natural frequency of the suspension, the natural frequency of the tyres, and occasionally the forcing frequency of something like braking bumps. In other words, a seemingly random motion of the front triangle, plotted against time, will show consistent frequencies of vibration once an FFT has been performed on that plot and graphed as a PSD. How is this relevant? Well basically, my measurements (which admittedly were at relatively low frequencies) showed NO significant density of power (ie no significant vibration) at anything above the natural frequency of the bike's suspension - ie the structure really wasn't making any significant difference compared to the suspension.You are obviously very knowledgeable. I can't compete with some of your technical language and won't try.
Sure, for the same material, a stiffer structure will ordinarily have more vibration. But we are talking about different materials, with different physical properties. Did your thesis include a comparison of metals vs. polymers?
Metals act like a spring, with no damper, so they vibrate more. Polymers do both, and with built in damping, they vibrate less. You don't have to believe me, but it's true.
Anyway, I've made my points, the horse is long dead.
My thesis didn't include a direct comparison of metals vs polymers, in fact the aim of my thesis was to create a mathematical model of bike suspension incorporating the rider, which proved a lot more complex than I expected. Story for another time though. I'm sorry for the extremely technical language, this is stuff I generally hate trying to discuss so specifically because if you haven't got an engineering or mathematical background then a lot of it is going to sound like some kind of turbo encabulator, however I (ironically) generally try to avoid generalisations.
Exactly, and this is where flex-stay bikes such as the Cannondale Scalpel, Lahar M9 etc have managed to use the anisotropic properties of CF to their advantage. However, I'm yet to see any DH bike where VERTICAL compliance was a goal of the structural layup (yes the Lahar has a flex stay, however that was simply in place of a pivot - the main swingarm was EXTREMELY stiff in all directions), unlike road and XC bikes (rigid/hardtail frames) where this is actually commonplace.
And as I've said, if the frame was designed to be compliant in that direction, you might notice it. A lot of road/XC carbon frames are designed to be vertically compliant but laterally stiff, but I'm yet to see a DH frame where the objective was anything but stiffness and effective transmission of input forces at the wheel to the shock. When you have 8-10" of adjustably-sprung and adjustably-damped suspension, plus tyres of easily variable pressure, why would you even bother trying to add in a couple of millimetres of vertical compliance through the structure of the frame (everybody also please note that the swingarm of the new V10 is aluminium anyway...) that can't be adjusted and is entirely dependent on lab measurements of force-displacement characteristics?
Once again, I am fully FOR the development of carbon frames, just to make that one clear, just not because I believe it's legitimately more compliant when used in a DH frame.
Last edited:
http://www.pinkbike.com/news/steve-peat-worlds-interview-2010.html
Check around the 3:35 mark. He's been riding it all year, though he is speaking on SC'ss behalf. I believe him. Come on, it's steve peat, you can't argue with that.
Check around the 3:35 mark. He's been riding it all year, though he is speaking on SC'ss behalf. I believe him. Come on, it's steve peat, you can't argue with that.
Many riders officialy back their product up and when you talk to them unofficialy they are less than happy. Not to mention the not so old santa rumors
Though Im not doubting that its a bad bike. I only say its silly to belive anyone whos job is to promote a product.You mean the guy who's paid by SC? Who actually made no comment on the material properties making the difference in harshness? Who is riding a bike with different geometry AND SUSPENSION CHARACTERISTICS, with a different rear shock, despite still having an aluminium swingarm and lower link?
Sorry mate, doesn't fly. Believe what you want, but believing something doesn't actually make it true!
Nor does not believing something make it untrue.
And all the maths, physics, theory and thesis writing cannot and does not substitue for real world, pudding proof, actual riding. For example, I know for a fact, through my own personal riding experience that a steel downhill bike gives a much less harsh ride than an aluminium one and as you know steel is a much stiffer material than aluminium.
At the end of the day the Carbon V10 is a fully sick bike and carbon is a far far superior material for a high performance race chassis than aluminium alloy. Thats both my personal opinoin and my profesisonal opinion as a research and development materials scientist.
Carbon composites are the future for the downhill race bike.
And all the maths, physics, theory and thesis writing cannot and does not substitue for real world, pudding proof, actual riding. For example, I know for a fact, through my own personal riding experience that a steel downhill bike gives a much less harsh ride than an aluminium one and as you know steel is a much stiffer material than aluminium.
At the end of the day the Carbon V10 is a fully sick bike and carbon is a far far superior material for a high performance race chassis than aluminium alloy. Thats both my personal opinoin and my profesisonal opinion as a research and development materials scientist.
Carbon composites are the future for the downhill race bike.
Last edited:
I agree with you on material properties, but based on what I have felt riding carbon vs aluminum FS bikes, the carbon is a smoother ride.
You can tell me I'm wrong as much as you want, but I'll believe what I've felt, because that's how it is
Steel bikes almost universally use FAR smaller diameter tubing than the equivalent aluminium bikes, and that reduction in 2nd moment of area is what gives them their compliance, not the modulus of elasticity itself. Virtually no carbon fibre bikes are using tubing of significantly smaller diameter than the equivalent aluminium bikes! That said, I'd still be extremely surprised if you could legitimately notice, in a blind test, a significant difference in harshness between a steel dowhill frame with 8+ inches of travel and an alloy one if the suspension settings and the tyres were the same. As you should well know, there is no magical material property that makes one material inherently "less harsh" when used in bicycle frames irrespective of the construction! A steel frame of equivalent 2MoA for all tubing and parts, as well as weighing about 3x as much as the aluminium equivalent, will also be about 3x as stiff. A high modulus carbon fibre frame with the same 2MoA for all tubing (identical shape, diameter, wall thickness) will be up to 5 times as stiff as the aluminium equivalent. As someone who works on this stuff all the time, I'm sure you're well aware of this. I also find it funny how people seem to think greater degrees of "material damping" is the reason CF road/ht frames are typically less harsh than their alloy counterparts - ever increased the compression damping in your fork or shock and found it made the ride LESS harsh? If you have, give Westminster Abbey a call, ask for Isaac and tell him he was wrong on many counts.
As I said, I've actually ridden a few FULL carbon bikes, not just the carbon front triangle V10, as well as steel ones, alloy ones - you name it, if it's available to the general public it's fairly likely that I've thrown a leg over it at some point. I have both the first hand experience and the physics to back up my opinion. However, I agree, CF definitely has potential to be WAY better for pretty well all high-performance bikes. I think it's just a matter of time until the manufacturing methods become consistent enough for long enough that people actually start trusting them though, people are still scared by the carbon disasters of the 1990s.
And based on what I've felt riding carbon vs aluminium vs steel bikes, I have felt no such difference. It's like how many people I knew swore black and blue that their mate's old DHR got "bad brake jack" because it was a singlepivot, but that their Kona Stab didn't because it "wasn't a singlepivot". They believed it to the point where they honestly thought they were feeling something different.
But whatever, buy the damn bike, being a Santa Cruz you can be fairly sure it'll be sick to ride and be relatively unlikely to snap in half on you. I'm not going to argue the point any further, trying to convince people that what they WANT to believe is wrong is a waste of everybody's time.
Last edited:
I still <3 you socket.
Do you mind me asking what you do for work? I'm guessing you're an engineer, what is your degree in?
Do you mind me asking what you do for work? I'm guessing you're an engineer, what is your degree in?
Harhar, the first "non-working appliace" manufacturer that came to my mind was also Sony
http://www.theonion.com/video/sony-releases-new-stupid-piece-of-****-that-doesnt,14309/
Socket: are you still in Whistler?
If so, gimme a shout if you see me in the lift line. I'm the guy with a neon green Ibis Mojo HD with a gravity build. I highly doubt you've ridden one and I'd imagine it's a fair bit different than the full carbon bikes you've seen around the village. You're welcome to take it for a couple laps.
Perhaps your opinion will change after. Perhaps not. Can't hurt to try, right?
If so, gimme a shout if you see me in the lift line. I'm the guy with a neon green Ibis Mojo HD with a gravity build. I highly doubt you've ridden one and I'd imagine it's a fair bit different than the full carbon bikes you've seen around the village. You're welcome to take it for a couple laps.
Perhaps your opinion will change after. Perhaps not. Can't hurt to try, right?
Socket...really interesting discussion. I'm an ME by training as well, and would be curious to read anything else on this topic. Was your thesis published at all? Any other good reference sources?
Nah, out of Whistler sorry. Might be back next year.Socket: are you still in Whistler?
If so, gimme a shout if you see me in the lift line. I'm the guy with a neon green Ibis Mojo HD with a gravity build. I highly doubt you've ridden one and I'd imagine it's a fair bit different than the full carbon bikes you've seen around the village. You're welcome to take it for a couple laps.
Perhaps your opinion will change after. Perhaps not. Can't hurt to try, right?
Nah wasn't published except within my university's library. The aim of the thesis was to develop a conceptual mathematical model of a bike's suspension when the rider is incorporated, which was only partially successful, but it did involve me building a test rig that was essentially a single post shaker for the rear suspension of a bike. I know of no other directly related research on the topic unfortunately!