Because the opportunity for manufacturing defects is so high with composites all composite parts for aerospace are tested with ultrasound to check for wrinkles, dry spots, voids, debris etc.Never even thought about ultrasound for consistency or discontinuity...radiography for density lines..
The top tube and down tubes are so freaking thin on all these carbon bikes it's like a drum...you can push it in a little with your thumb..don't know that I care enough for it to make me nervous, but I do know they don't like rocks at all...
Think I'm going to ride wrap or throw heavier mil clear on sides of bike and stays to protect it from shock impacts and sharp hits...not an end all but there's a couple areas I'd be cool with some buffer
I've always assumed pre-preg carbon bike parts are overbuilt to allow for inconsistencies. Otherwise (and without ultrasound checks) most units with inconsistencies wouldn't pass stress tests or would result in warranty claims.Because the opportunity for manufacturing defects is so high with composites all composite parts for aerospace are tested with ultrasound to check for wrinkles, dry spots, voids, debris etc.
On a bike, you are the test.
And race face components. Ballsy.Trust carbon enough to build this last night. (Carbon front/Alu rear)
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Who knows. Might even be brave enough to ride it one day.
All composites need to be overbuilt to a certain extent to compensate for variability in the end product. There is certainly going to more variability compared to metals. You can reduce variable with tighter and more expensive process controls.I've always assumed pre-preg carbon bike parts are overbuilt to allow for inconsistencies. Otherwise (and without ultrasound checks) most units with inconsistencies wouldn't pass stress tests or would result in warranty claims.
One of the differences between two "grades" of carbon frame (Scott HMF vs HMX, Santa Cruz C vs CC) is more skilled, higher paid workers doing a more consistant job of the layup so they don't have to overbuild as much, saving weight.
Yeah. Seat tube angle. I've got long legs so I have to get offset seat posts. You know, knees and hips and stuff. Old man syndrome in there too.I already have 2 other vitus bikes.
I bought this new warranty frame (no shock) in Large at a good price. (obvs with no warranty) To swap all the parts from this XL Giga .
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The Giga is XL (490mm reach which is 20mm longer than an L) the rest of the geo is very similar between the two. I'm a tiny bit under 6ft. The Giga was a very capable, stable AF, fast descending frame and I had no issues riding it but I just didn't enjoy its lack of playfulness and maneuverability over my many other shorter bikes. I don't have a DH bike anymore (the Giga is faster DH than any of my old 26" bikes were) so the Giga was partly to replace their job as well as trail riding skewed towards descending. As will the Sommet. But at 470mm reach. It should feel a lot moar fun to ride. Just as a L Giga is (which I far prefered riding to the XL). I've increased the shock stroke so the Sommet also now has 170mm rear travel in full 29" wheel configuration the same as the Giga. (180mm fork).
Brief ride to set Sag etc. after building it told me straight away it fits my preference better. Seattube angle seems a little slacker than the super steep Giga's. (I'm not really a fan of super steep S/As unless the bike is verging on too long. Which as explained I'm not that much of a fan of either)
Yeah I got certified iirp radiation safety with California for open source cobalt and iridium as well as NDT II for ultrasonics, mag particle, dye, Eddy, Vis, radiography...but studies and field was petroleum, nuclear regulatory , aero space, naval and infrastructure......Because the opportunity for manufacturing defects is so high with composites all composite parts for aerospace are tested with ultrasound to check for wrinkles, dry spots, voids, debris etc.
On a bike, you are the test.
Yeah. Seat tube angle. I've got long legs so I have to get offset seat posts. You know, knees and hips and stuff. Old man syndrome in there too.
But really, Hmm...If I'm going to ride the lift at the bike park and try to hit all the features, proper style, I need a DH bike. A big hit single crown could probably do the job. But, IDK, the nostalgia in me says just get a DH bike. You (I'm talking to myself) already have plenty of other bikes. N+1. DUH.
Brain "What you need a million dollars heres a check, oh you need on too sure let me get right on that.." I'm bouncing checks like a b-baller...Just try not to let your brain write cheques your body can no longer cash.
You don't miss a proper DH fork? Even a lowered one?Realistically I don't really ride DH at a decent level anymore and it's extremely rare I'd travel to either of our two chairlift tracks. Granted if I were to it'd for sure be nicer to be on a modern DH bike but this thing is pretty much as long/slack as any DH bike I'd have and at 170 rear, 180 front with DH tyres. it won't really be holding me back anywhere else.
teaches you to use a backpack next time, like a normal personWhich reminds me I have a leyzene CF bottle cage to fix. Last race the bolts to the frame were loose and during the race they got progressively looser to the point where one bolt fell out and my pump and bottle cage went sideways. I got all my mix down and chucked the bottle in a bush and tried to keep riding, but the bottle and pump jammed my cranks, so as fast as possible, I yanked both of them free, breaking the pump mount and cracking the cage, where the bolt goes through. Didn't seem to affect my frame. Chucked those all and the pump on the other side of the trail. All in all probably cost me 10-15s, maybe a few more having to slow down just before. Got going again and finished 6th, was gaining on the rider ahead, but we were spread out enough that I dont think the cage debacle was decisive.
Wen out next day and recovered all the parts.
The cage looks repairable, unlike the bottle mount. I have 3x weave and resin too.
I always ran my DH fork slightly oversprung with less sag than most and have tons MOAR riding time on old skool 32mm stanchion boxers than the newer 35s. Apart from a couple of years on Monster Ts around 99/00 I didn't ever ride anything stiffer (oo er missus). then managed a couple of seasons on shivers. Possibly the least accurate steering fork evar.You don't miss a proper DH fork? Even a lowered one?
I went to a Zeb to a Lyrik awhile ago and I'd tend to agree depending on the circumstance. For shorter runs in really chunky terrain I love the Zeb, in some ways its less harsh - I feel like it works better under heavy braking than the Lyrik did, and it performs better suspension wise when it is subjected to cross-rutting etc.I know it's blasphemy these days, but I wish you could still run Lyriks at 170mm. I've ridden latest & greatest Zeb and Lyrik back to back at 160, and I just prefer the feel of the smaller air spring. The larger diameter one in the Zeb ramps up a lot more strongly deep in the travel, even with zero tokens. For what I ride, I never feel like the Lyrik is flexy, if anything, I feel like the extra stiffness of a 38/Zeb is more tiring. Kinda like running uber stiff wheels.
Totally agree.I know it's blasphemy these days, but I wish you could still run Lyriks at 170mm. I've ridden latest & greatest Zeb and Lyrik back to back at 160, and I just prefer the feel of the smaller air spring. The larger diameter one in the Zeb ramps up a lot more strongly deep in the travel, even with zero tokens. For what I ride, I never feel like the Lyrik is flexy, if anything, I feel like the extra stiffness of a 38/Zeb is more tiring. Kinda like running uber stiff wheels.
Sounds like a candidate for those "reverse volume token" foam things. Was Formula selling those?The larger diameter air spring in the Zeb ramps up a lot more strongly deep in the travel, even with zero tokens.
My complaint with a 170mm Fox 36 was bushing bind caused by flex on braking bumps. It felt fine until you hit the brake, then it would get MUCH more stiction and be very harsh over braking bumps. A 38 feels much stiffer fore/aft and absorbs bumps much better under braking.For what I ride, I never feel like the Lyrik is flexy, if anything, I feel like the extra stiffness of a 38/Zeb is more tiring. Kinda like running uber stiff wheels.
I know what you're talking about, those funny "carbon air" cartridges. I've looked at them, but I'm very skeptical. They're also expensive as fuck, like $200+ last I looked. And they supposedly wear out / get saturated over time needing to be replaced.Sounds like a candidate for those "reverse volume token" foam things. Was Formula selling those?
The 38 needs more air because of its lack of compression dampingI know what you're talking about, those funny "carbon air" cartridges. I've looked at them, but I'm very skeptical. They're also expensive as fuck, like $200+ last I looked. And they supposedly wear out / get saturated over time needing to be replaced.
What Fox did with the 38 was put a reduction tube inside the air side to keep the air shaft diameter closer to that of a 36 and make the spring feel similar. It definitely behaves like that when I've ridden 38s - I needed tokens and higher pressure than Fox suggests to keep from hard bottom outs. RS instead tried to balance the pos/neg chamber volumes differently, and I don't think they quite got it right. I've tried a Secus on the Zeb and I feel like it pushed the ramp really deep but then made it a bit sharper, while making small bump and midstroke better.
I really like the Charger 3.1 damper (have it on both my Zebs and Lyrik), so it's not a damper side thing.
Regardless though, I don't think it's unreasonable to want to run a 35/36mm fork at 170mm, especially given the improvements that have been made in bushing overlap, CSU interface, torque caps, etc. EXT's fork goes up to 180 at 36.
I reckon a Secus or one of those activated carbon wundertokens that actually increase the air volume would be the go. FWIW, I think the Zeb's progressivity comes from the lowers as much as from the air spring itself.
Runt has definitely crossed my mind, and even been added to cart more than once. The main reason I haven't is that I haven't is below - even with zero tokens it seems awfully progressive. I'm not sure how the Runt would actually help that - if I run the ramp low enough for it not to spike, I'll have terrible midstroke.
Yeah, that's what I was trying to get at. Maybe I really should get one of those carbon snake oil things in the name of "science."I reckon a Secus or one of those activated carbon wundertokens that actually increase the air volume would be the go. FWIW, I think the Zeb's progressivity comes from the lowers as much as from the air spring itself.
interesting...i have zero issues with my 38...but maybe i'd be even moar happy if i runted it nao???Runt made that FUCKTARD of a fox 38 fork I had worth a shit...
This is my experience is well. Haven't done a Zeb/Lyrik comparison though.My complaint with a 170mm Fox 36 was bushing bind caused by flex on braking bumps. It felt fine until you hit the brake, then it would get MUCH more stiction and be very harsh over braking bumps. A 38 feels much stiffer fore/aft and absorbs bumps much better under braking.
I'll preface this with less ignorant prejudice...everyone has a different style, size, weight, torso and so on ..some come from my others from BMX...so we all rise different and I don't think there is one perfect item for everyone for riding besides just having a bike and build it to you..interesting...i have zero issues with my 38...but maybe i'd be even moar happy if i runted it nao???
i do wish mine was a bit more supple. don't mind progressive...i'm a 170# hack...on the dh i'm more plow than air...I'll preface this with less ignorant prejudice...everyone has a different style, size, weight, torso and so on ..some come from my others from BMX...so we all rise different and I don't think there is one perfect item for everyone for riding besides just having a bike and build it to you..
I got another Zeb the other day to play with some more also ordered a new rfx38 for the slashs rebuild after breaking...I want to play with the Zeb a bit next couple weeks more than I did, some different terrain and really take a day to dial it and see...the 3.1 is good the 3 had some issues with lighter riders again I think it's stuff chasis matched with too stiff of a platform on charger 3...(Burnish fork .14, drop oil to 5wt 19 CST and it comes to life)
That's said..
I like the way a coil rides I like a linear consistent feel ..why I prefer Ohlins as well . But the runt made the 38 more consistent and predictable than it was...also not a fan of a 34mm air chamber versus a 36 is bigger ...should have gone the way of the 40 on air chamber but for 38....I didn't get a long with it real well...tried I was digging fox but after an injury and riding different stuff it fell short on the list down...even my fox 40 is avalanche spring and open bath...rest of bikes are now all ohlins...
I think it's too (chasis) stiff, too progressive and it fights itself...matches with a damper and limited comp it never felt right...I can see where it would work for a different style rider for sure though....
This is exactly what it's about..this is a crap ton more fun then my ritual...i generally find something that feels about right and forget it....
Because the opportunity for manufacturing defects is so high with composites all composite parts for aerospace are tested with ultrasound to check for wrinkles, dry spots, voids, debris etc.
I think this gets overstated a bit when it comes to bike manufacturing. Aluminum alloy frames have a lot of areas to have manufacturing defects as well, there's probably more recalled aluminum frames than carbon out there. It turns out to be "easy" to forget to weld all the way around the headtube (the way the downtube, headtube and top tube come together and are welded turns out to be important), or drilled some extra vent holes, or "forgot" to heat treat the frames again after a thermal event that would weaken them. As price for aluminum frames went down, some of the fine art/attention to detail/process control gets lost in the higher volume facilities.Because the opportunity for manufacturing defects is so high with composites all composite parts for aerospace are tested with ultrasound to check for wrinkles, dry spots, voids, debris etc.
is that a result of there simply being much, much higher volumes of aluminum frames being manufactured, or is the incident rate of defects/failures actually higher? (or both?)I think this gets overstated a bit when it comes to bike manufacturing. Aluminum alloy frames have a lot of areas to have manufacturing defects as well, there's probably more recalled aluminum frames than carbon out there. It turns out to be "easy" to forget to weld all the way around the headtube (the way the downtube, headtube and top tube come together and are welded turns out to be important), or drilled some extra vent holes, or "forgot" to heat treat the frames again after a thermal event that would weaken them. As price for aluminum frames went down, some of the fine art/attention to detail/process control gets lost in the higher volume facilities.
This looks like a pretty common failure mode, one I used to see a lot. Seatstays don't need to be super strong compared to every other tube on the bike, but they get whacked in a crash or tip over pretty easily and thats enough to break em. If you still have the piece, cut open those rectangular stays and look at the cross section. What I found after some investigation was that the corners get thin, must be some dynamics in the mold with the bladder inflation into the corners and ply migration or some such. We designed an impact test that hit the seatstays on the side, and then experimented with different ways to make it more fracture resistant to impact like that. We ended up using a tow fiber method in the corner. Imagine taking a piece of UD prepreg thats 18" x 1". Roll it up so you end up with a fat piece of spaghetti thats 18" long, and place one on each corner of the rectangular tube. It reinforced the corners so the tube would resist fracture when hit. That reduced failures significantly.Not sure how much faith I have in carbon right now...I've broken my fair share of alot of frames and parts over the years.. but the way this snapped isn't like alloy..Ive dented alloy, trenched it, gashed it and cracked it...
Did have a buddy snap a head tube clean off his alloy intense. (So there is always that)
I like a damaged spot I can keep an eye on versus no in-between just good/fail replace...
I am swapping carbon bars to deity alloy now and cranks more than likely..took a look at the carbon cranks on the slash and they were gashed and pretty hammered after 5 rides...some of them are trenched pretty bad..
I'll still ride carbon frames , all 3 are carbon..I do have a steel one coming, but I question carbons durability with my weight and rock piles. Or anyone heavier hitting a rock or drop just right big or small it goes from zero to snap in just like that..
Just thoughts on it from others...
i don't know the answer to that - probably some of both. Could be that you can often identify what the defect actually is on the aluminum when you examine it so "the remedy" to fix it is more cut-and-dry. The number of variables is fewer, but that also means screwing up one thing, like using the wrong welding rod, etc. can have a big impactis that a result of there simply being much, much higher volumes of aluminum frames being manufactured, or is the incident rate of defects/failures actually higher? (or both?)