I would like to assume that manufacturers do not put out dicked-up designs that don't have wild rate changes that make no sense or really don't work with the shock speced..but...
Talk Me Out of a Capra 29?
- Thread starter Lelandjt
- Start date
How would you even measure stiffness? Stiffness of frame? with or without wheels? And is moar stiff moar better? I feel stiffness is really misunderstood. take wheels for example. At first everyone was like "carbon is great caus' it's stiff". Now, carbon rim manufacturers are falling all over themselves to re-introduce compliance back into the rim. But only vertical compliance. I wonder how long before they start introducing lateral compliance as well, caus' tests show it's faster (or some other marketing bs).
I'm a little cynical about this right now, caus' I'm helping a (very fast) buddy try and improve his Fox 34. He knows he's not happy with it, but can't even begin to explain why he doesn't like it. He filled in Vorsprung's questionnaire for a Fractive tune (when I suggested he start with a Luftkappe kit), and rated himself an aggressive rider (IMO, he's one step down from aggressive, but close enough). Yet he says he favours compliance over support. He has no idea what either of those mean in a fork. No idea. And yet he's fast. very fast. But if you start adding descriptors like stiffness to frame selection, it will be just another way marketers will be able to sell him more useless shit... (like the Enve rims he bought, which I'm convinced make his shitty 34 even shittier by highlighting the shit damping, and shit spring curve). and he'll have no friggin clue.
on the other hand, some people are just nerds, and enjoy thinking about it. I hope to FSM they don't enjoy thinking about it as much as they enjoy riding, but eh! to each their own I guess.
I'm with you on this one. The low-end 34 I had felt like it came from factory with Specialized's Brain damper. No matter how low the air pressure you'd run, it jackhammered all over the place when not riding smooth, flowy trails. And a VERY fast XC racer I know ended up switching his 29" Enves for a wet of aluminum DT Swiss wheels, since the extra stiffness in the Enves kept getting him out of line when facing roots or rocks.
Plus everyone knows the Industry Standard ™ for "stiffness" is moar variable -and not as predictable- as weather. Their statements on that issue are usually pulled off some marketing guy's ass without any justification whatsoever.
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When people start designing more sideways flex in hardtails, I'll believe this. Hardtails are kind of the ultimate in this respect and I don't see people complaining left and right that they are too stiff (laterally).
People riding rigid 29+ bikes with carbon rims are complaining they are too stiff because they are trying to rely on 8psi to provide suspension. The reason I like carbon rims is precisely because they are massively stiff and I can push them into a berm/turn and they hold a line better and don't flex all over the place, which ultimately means I can carry more speed/go faster.
He is talking about wheelrate stiffness here.
Apparently I'm not the only one that thinks the Fox 34 is a pile of horseshit?
I'm gonna swap it out for a Ribbon Coil.
I'm gonna swap it out for a Ribbon Coil.
I am with you Gary, at the end it is all about the fun on the woods!
But how do you buy a new bike? You go for a nice paint job, the last winning bike from your favorite pro combined with the latest gear from Sram?
Some facts are helpfull even if it is difficult to get the whole picture.
Ha ha... there might be a little too much truth in that. (for DH bikes anyway)But how do you buy a new bike? You go for a nice paint job, the last winning bike from your favorite pro combined with the latest gear from Sram?
I haven't ever owned a DH bike that hasn't at least won a UK National. Infact 8 out of the 10 DH bikes I've ever owned did win at least one world cup. 7 of them won world champs.
TBF if you're complaining about performance of the suspension design of a bike that won the biggest DH race in the world. Your problem is probably more to do with YOU than the bike.
I chose my Capra after riding 3 other folks. I can't think of any pro who rides one other than Lacondeguy. And it's not even the bike he's known for riding. Info from suspension and tyre nerds @Udi and @kidwoo actually did help me reach that decision.
A geek around here is definitely helpful but I wouldn't ever buy a bike based solely on info read here.
If you knew what new bike I have just bought this would become hugely apparent.
enjoy your new intense!Ha ha... there might be a little too much truth in that. (for DH bikes anyway)
I haven't ever owned a DH bike that hasn't at least won a UK National. Infact 8 out of the 10 DH bikes I've ever owned did win at least one world cup. 7 of them won world champs.
TBF if you're complaining about performance of the suspension design of a bike that won the biggest DH race in the world. Your problem is probably more to do with YOU than the bike.
I chose my Capra after riding 3 other folks. I can't think of any pro who rides one other than Lacondeguy. And it's not even the bike he's known for riding. Info from suspension and tyre nerds @Udi and @kidwoo actually did help me reach that decision.
A geek around here is definitely helpful but I wouldn't ever buy a bike based solely on info read here.
If you knew what new bike I have just bought this would become hugely apparent.
Not me. A Factory FIT4 at 150mm or less (ideally 130/140) on the right bike is stellar. Pretty much a Pike with a better damper.
Also, sorry for the thread hijack. No idea how a 34 came up in a Capra 29 thread, but that's RM for you.
Impulsive buying behaviour is ok too, I am actually waiting for my first fat bike
what about getting a Luftkappe and a Fractive tune?! could be cheaper... and there ain't nothin' wrong with the 34 chassis, as far as I know...
I hope you have snow where you live. and snowshoe trails you can poach.Impulsive buying behaviour is ok too, I am actually waiting for my first fat bike
Yes I do and I will give a try to bikepacking which I might like since I have been doing quite some backpacking before having a kid.
Higher spring rate and more progression both give you higher wheel rate. However, higher spring rate alone affect wheel rate across all travel range, including at top out, where you don’t often need a higher wheel rate, it also lower sag so geometry and negative travel is affected (could be for the worst or not). On the damping side, it decreases the damping ratio as you are increasing spring forces while keeping damping forces constant.
I agree however some too progressive designs give harshness feeling too like the intense 951 or just putting maximum volume spacer in some shock of fork configuration. Some of these could definitely feel like you hit a wall of brick!
I agree the demand might be low but I think it is more based on the fact it is hard to process, a geometry chart is quite easy to process, a bunch of cluttered graphs are hard to interpret and put into relation in a meaningful way.
As for Vital publishing curves, I think it helps to raise awareness but I think it’s still hard to draw conclusion from these especially when you mix coil and air.
It’s very hard to develop products AND make sure it is profitable, I acknowledge that 100%, but I also believe that an educated consumer base can only have beneficial impact on what we are offered. Right now I feel it’s not encouraging for people to try and develop products offering a technical advantage because marketing is king and there’s so much noise and misinformation.
I respect the fact that you don’t put value on it but I think it has the same amount of value as many other things you look at when making a buying or setup decision. I think we are riding the bikes we are today because some people got interested in geometry, suspension, materials, fluid dynamics etc…
I guess you are paying attention to your handle bar length, cockpit height, spring rate/air you ride, your tire knob design, geometry chart, the size of your wheel, your fork offset etc. You do this to make a choice relevant to your personal preferences but I’m sure when you tell your coworker who ride occasionally for fun that you chose a bike rather than another partly for a 5mm difference on the chainstay length or a 1.5 degree difference on the head angle and then you cut your handlebar 10mm he’d look at you kind of weird haha!
If all of this is ok, how comparing wheel rate overthinking it? It makes as much difference of a difference than most of these things.
Not necessarily dicked up, you just have a pretty big range to choose from, is a 67 degrees head angle dicked up? I don’t think so, it just handle different than a 65 degrees head angle. Same thing with suspension designs, most of the range work but there sure is a broad selection to choose from. It just doesn’t help reading: yeah it’s supple in the beginning, supportive in the middle and have bottom out under control.
Agreed! Stiffness can be very complex and you are right that a bike stiffness can be expressed in MANY ways. You can have all the data in the world but if you can’t put it into perspective or present it in a intelligible way, it is worthless. But right now, it’s just all over the place in term of ride quality and you only have subjective reviews with bike specced differently ridden by different people to make up your mind. I would see how normalized stiffness tests for a couple of key scenarios be helpful like it is in road bikes. If some one didn’t like Enve wheels harshness or the way his frame is folding under him in corners, how can he know how are other option faring in that regards? He can’t but he can listen all day to some athlete getting free stuff raving about their respective their stuff that work soo good.
The day your friend will have the luftkappe set in his fork, he will either like it of not, but if he can have a way to see what make the two fork stand apart (wheel rate) he will be able to tell what is it that he likes or not and be able to apply that new knowledge to his setup and buying preferences. Nothing’s worst than buying something without knowing you will hate it but could have known!
Sorry for the long reply!
Sorry. I think you may have misunderstood my comment. When I said he was overthinking. I meant with regards to this:
"Has somebody experience with what difference having 30% of progressivity vs 60 to 70% makes?"
All those things you listed above pretty much come from trial and error. albeit with less error for an experienced rider.
Debating whether you want 60 or 70% progression on a mail order bike you've never ridden with a bunch of strangers who have also never ridden it i'm sure you'll agree is not likely to answer anything accurately.
Like I said. in my longer reply I don't even know for sure what his question even means.
I do actually agree with you that more information makes choosing a lot easier for anyone who does know what they're looking for.
I actually brought that up with Steve once - everyone thinks they're "aggressive". Or at least feels like they've been aggressive once because they bottomed their shock. Suspension tuners would have such an easier job if people had a fair idea of how they actually rode.
The problem with that logic is that it leads people to buy Orange 221s....
I agree with the over-nerding aspect btw, but it is really hard to test ride a lot of the bike that are available and if you're looking for something that fits and feels a certain way, then you've got to bust out the slide rule and protractor a little bit
Sorry if I sounded rude! that was not the goal. My comment was about you said it was sad people thought they needed such information, my point was just that it is as relevant as anything.
I'm with you that between 60 and 70 % progression it's pretty much a gamble but having previous references helps to grow your knowledge on what works for you
Haha... nah.
I don't think even I have been that drunk.
Oh. Yeah. I agree there. There's no point hankering after something new if there's something glaringly obvious that you're unlikely to get on with and that definitely sometimes takes a little nerding. Maybe I'm being overoptimistic but I think we probably all know enough here to have a fairly decent idea at least of what characteristics we really don't like in a bike.you've got to bust out the slide rule and protractor a little bit
I'm sorta lucky here in that I'm really close to the busiest mtb area in the entire country (it's kinda popular here). Ride this area a lot and with a little bit of patience the bike you've been looking at pretty much always comes along sooner rather than later. if it's something new usually with a proud new owner only too happy to tell you all about it. And I've never been shy in offering to evaluate others new bikes by way of a free test ride.
Seriously. even with something as new as this Capra I'll no doubt see one the next weekend I head out mountain biking.
Unless you spill my drink you've nothing to ever worry about there.
You do know i'm Scottish right?
Yeah. but what does 60% progression even mean?
I am actually curious as to how the new Capra's reduced progressivity compares to mine. Not that I'm unhappy with how mine performs in the slightest mind you.
For myself I started with the notion that 10=world cup caliber racer. 9=national level racer. 8=provincial level racer. I've ridden with guys that raced at the provincial level and they're faster, but I can keep them in my sights. So I chose 7. Then I described the trails I've ridden in the Whistler area, and how I did on certain classic Whistler trails. I figured that would give him a good idea of my level.
I suggested to my buddy that he do the same. Describe to him the trails he's ridden in Whistler, and what were his favorites and why. I figured that would probably help Steve out more than anything else. I hope.
Gary either got an intense or a fatbike. Both of which are unridabru.Ha ha... there might be a little too much truth in that. (for DH bikes anyway)
I haven't ever owned a DH bike that hasn't at least won a UK National. Infact 8 out of the 10 DH bikes I've ever owned did win at least one world cup. 7 of them won world champs.
TBF if you're complaining about performance of the suspension design of a bike that won the biggest DH race in the world. Your problem is probably more to do with YOU than the bike.
I chose my Capra after riding 3 other folks. I can't think of any pro who rides one other than Lacondeguy. And it's not even the bike he's known for riding. Info from suspension and tyre nerds @Udi and @kidwoo actually did help me reach that decision.
A geek around here is definitely helpful but I wouldn't ever buy a bike based solely on info read here.
If you knew what new bike I have just bought this would become hugely apparent.
Apparently my question is not so well formulated, sorry for expressing myself in a foreign language
maybe I should use progression instead of progressivity?I agree that 60 or 70% of progressivity is in the same range and would most probably not make a sensible difference.
The progressivity (progression?) I am talking about is a way to quantify how much the leverage ratio changes through the travel compared to a constant (aka linear) ratio. But I guess that you got that already.
I have tried during the last few months similar trail bikes all with coil shocks and with progressivity numbers of 11%, 25% and 28%. The 11 and 25% bikes were actually the same frame with just a swap for the rocker, @vincent had some good advice on that one!
The 11% bike was rubbish: it was either supple of the top with really poor bottom out resistance or harsh with high enough spring rate to avoid bottom out and compromised geometry because of 15% sag.
On the other hand, the 2 bikes with 25 and 28% progressivity were much more to my liking.
With that background, I wanted to know what difference 30 vs 60% of progressivity feels like. I know that I would have to try it for myself in order to really know but with the answers I have got so far, I have a fairly good idea where things would go even if it is just theoretically.
I made that mistake once while ordering a tuning kit. I don't remember if I had an overly good day or if beer was involved when I had to fill the information but I went for aggressive... The result was quite harsh. Leave and learn!
I agree progression is not really meaningful. Let's take the capra 2017 vs 2018 in 27.5Yeah. but what does 60% progression even mean?
I am actually curious as to how the new Capra's reduced progressivity compares to mine. Not that I'm unhappy with how mine performs in the slightest mind you.
The capra 2017 has ~65% progression vs ~55% for the 2018, both have ~170mm travel. What you are actually feeling is the wheel rate which is the firmness of the suspension, lower wheel rate means the suspension is softer and higher wheel rate means the suspension is harder, it's actually a much simpler and intuitive concept to understand than leverage.
With both bike set at 28% sag for a 81kg (180lbs) rider with 65% rearward bias here are some numbers:
with an approximation of a fox evol air can with no volume spacer.
Capra 2017 sag wheel rate: 0.94kg/mm (52.5lbs/in)
Capra 2018 sag wheel rate: 0.95kg/mm (53lbs/in)
The rate is the same between those 2 bikes but it is not always the case, it is not because you ride your bike at the same amount of sag as another that the firmness will be the same at sag.
Capra 2017 end stroke wheel rate: 9.7kg/mm (542lbs/in)
Capra 2018 end stroke wheel rate: 7.4kg/mm (413lbs/in)
That's a rather large difference if you ask me!
If you would go and put a coil on the bike (with same sag) here's the numbers:
Capra 2017 sag wheel rate: 1.20kg/mm (67lbs/in)
Capra 2018 sag wheel rate: 1.25kg/mm (70lbs/in)
more support at sag than air!
Capra 2017 end stroke wheel rate: 3kg/mm (167lbs/in)
Capra 2018 end stroke wheel rate: 2kg/mm (111lbs/in)
The relative difference is the same as with air but the end stroke rate is much lower. keep in mind the shock bumper is kept out of the equation.
Obviously there's more to it than just a picture at sag and at bottom out but you get an idea of the feel you experience much better than with leverage ratio.
Again, These were calculated with approximated but fairly accurate frame and shock data, don't take these as the absolute truth.
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I'm surprised that we're on 90 post and still on topic. Usually by post 8 we'd be arguing about the color of the interior of your car or something else useless.
Yeah. this is exactly what I was getting at with in querying @Happymtb.fr's question comparing progressivity as a percentage.
thanks for taking the time to do all the slide rule shit BTW. Pretty awesome info.
For the percentage I do:
100×[ (leverage ratio at beginning of the stroke / leverage ratio at the end of stroke) -1]
This works well for leverage ratio that are progressive only. If there is smal regressive parts in the leverage curves, you can skip them and go for the highest and lowest values instead. If there are large regressive parts, then I try to forgot about this bike.
The Intense 951 was notorious for being too progressive. How did it compare to the 2 generations of Capra?
“allegedly”
Lots of people I know rode those and loved them. Maybe the concept was ahead of its time, but if I remember right, the progressivity was such that full travel could never really be reached, even with a coil.
For discussion sake here is the leverage ratio from the 2016 Capra (as far as I know the 2017 was pretty much identical)
The full video includes anti squat curves, chain growth, pedal kick, and axle plot graphs. Interesting stuff. Probably watch on mute unless you like bad music.
The same dude has an interesting discussion on "progressive" suspensions. Things start getting good around 1:00. He compiled some interesting charts on different bikes and how progressive they are.
I should mention that all his calculations assume a coil shock so everything goes out the window with air shocks cause they have a progressive force curve of their own. But coil is a good baseline to use.
The full video includes anti squat curves, chain growth, pedal kick, and axle plot graphs. Interesting stuff. Probably watch on mute unless you like bad music.
The same dude has an interesting discussion on "progressive" suspensions. Things start getting good around 1:00. He compiled some interesting charts on different bikes and how progressive they are.
I should mention that all his calculations assume a coil shock so everything goes out the window with air shocks cause they have a progressive force curve of their own. But coil is a good baseline to use.
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I know man. For a bit he was coming on here and promoting his stuff. He never really seemed to get into the conversation though.Hey @andrextr
I've been nerding out on @Steve M's Vorsprung channel too. He gets into some interesting stuff regarding why low speed compression will actually make high speed stutter bumps feel harsh in this video.