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Stainless Steel DH Frame

VELOMECH

Chimp
Jun 15, 2012
18
0
Thanks for all the support, everyone!

Lets try to not let this thread turn into a random engineering gibberish generator. Save that for a frame building forum or better yet, an engineering forum.
If you want to know more about the tubes used for this frame, have a look at this link:

http://www.kvastainless.com/tubing-info.html

If you disagree with the manufacturers >200ksi claim or have other unanswered questions, please take it up with them directly. I'm not a tube manufacturer and cannot speak intelligently about their patented process.

It looks like we are just a couple days away from having the 250 votes required to qualify for the final round of Grant nominees. Then we can talk about bike specific stuff like how it rides, some design concepts and theories, aesthetics, ideas for how this prototype might evolve etc.

Again, thanks for all the positivity you guys are sending out.
 

sikocycles

Turbo Monkey
Feb 14, 2002
1,239
250
CT
Thanks for all the support, everyone!

Lets try to not let this thread turn into a random engineering gibberish generator. Save that for a frame building forum or better yet, an engineering forum.
If you want to know more about the tubes used for this frame, have a look at this link:

http://www.kvastainless.com/tubing-info.html

If you disagree with the manufacturers >200ksi claim or have other unanswered questions, please take it up with them directly. I'm not a tube manufacturer and cannot speak intelligently about their patented process.

It looks like we are just a couple days away from having the 250 votes required to qualify for the final round of Grant nominees. Then we can talk about bike specific stuff like how it rides, some design concepts and theories, aesthetics, ideas for how this prototype might evolve etc.

Again, thanks for all the positivity you guys are sending out.
More pictures of the bike please
 

HAB

Chelsea from Seattle
Apr 28, 2007
11,087
1,381
Seattle
Sorry for the sidetrack. The bike looks great, and as the happy owner of another one off steel DH bike I'm a huge fan of the premise. I've got some questions I'd love to hear answers to but I'll wait until you've hit 250 votes if you'd prefer. You've got mine for sure. Great work, keep it coming.
 

VELOMECH

Chimp
Jun 15, 2012
18
0
250+ votes are in! Big thanks for all the support.

Now I owe you guys some info.
Keep in mind, this bike is a proto and not slated for production/sales until early 2013. Some small details (like HT dia. and ST dia.) will be changing because I had to make do with the materials I could find when the proto was built.

Brand: Oxide Cycles
Model: Valkyrie
Intent: Ripping purpose built DH trails
Design Goals: Simple, Reliable, Easy Maintenance, Flex in the right places, Rigidity in the right places, Tunable, Multiple wheel size options, Multiple drivetrain options, Vintage race car / motorcycle inspired design.

Two sizes: Regular and Long (Proto is the long version)
Long size specs=
TTH: 24.6
Reach: 18.3
Stack: 24.2
HA: 65*
CS: 16.7-17.9 (min/max range of sliding dropouts and eccentric BB)
CS growth at sag: .25
CS growth max: .32
WB: 48.6 as currently configured
Frame weight: 8.7lbs
Bike weight as shown: 33.7lbs
180mm travel F&R

If I were to describe the ride in one word: Smooth

Between the vibration damping qualities of the frame, the big wheels and the superb fork/shock it rides butter smooth.

Pedal bob is minimal. I don't notice any torque induced bob, only a small amount of movement from the mass oscillation of my legs. Bikes I've ridden that have a similar pedaling feel would be the Intense VPP bikes and Canfield F1 Jedi. The DW link Pivot Phoenix has a firmer pedal feel for example. I was expecting more of single pivot feel like an Orange or Santa Cruz Bullit but with those you notice more reactivity from the drivetrain.

One of the nicer characteristics I have noticed (and others that have tried the bike) is the cornering feel. Some bikes feel too upright and won't lean in, while others tend to pull in too much. This bike initiates turn in freely and settles into the corner radius you choose and just stays there. It doesn't try to tip in further or straighten back up. Has that on-rails cornering feel that I really like.

What else do you guys want to know?
 

VELOMECH

Chimp
Jun 15, 2012
18
0
All the tubes are KVA
Small parts are either 17-4 or 316
The pivot shaft is 7075 aluminum and turns on four bearings (two each side) They are Profile racing BMX crank bearings, so you can R&R them with a standard outboard bearing tool. No hammers, no proprietry press tools. Available through any bike shop. I've been a traveling bike racer and have been burnt by fancy designs and hard to find parts that require proprietary tools. I want to be able to travel with this bike and never miss a day of riding. I could have designed a spiffy linkage arrangement, but did not want the weight (bearings, shafts, links) and complexity (more to maintain, more parts to break). That is why I decided on a single pivot and a highly tunable shock. I'll run single speed (quiet and reliable) until I can build a proper gearbox bike.

is it all KVA tubing, or did you mix materials?
 

descente

Monkey
Jul 30, 2010
430
0
Sandy Eggo
yea, i dig it and the simplicity. i'm really curious about the construction, as i'm currently materials shopping for a frame project of my own.

did you TIG it, or do i see some lugs in there as well (specifically around the upper shock mount)?
mind if i ask what tubing sizes you are using? i just poked through KVA's website and it all seems a little on the small side for DH use. i also didn't see anything that would be big enough to turn into a 1.5/tapered head tube...
 

sikocycles

Turbo Monkey
Feb 14, 2002
1,239
250
CT
250+ votes are in! Big thanks for all the support.

Now I owe you guys some info.
Keep in mind, this bike is a proto and not slated for production/sales until early 2013. Some small details (like HT dia. and ST dia.) will be changing because I had to make do with the materials I could find when the proto was built.

Brand: Oxide Cycles
Model: Valkyrie
Intent: Ripping purpose built DH trails
Design Goals: Simple, Reliable, Easy Maintenance, Flex in the right places, Rigidity in the right places, Tunable, Multiple wheel size options, Multiple drivetrain options, Vintage race car / motorcycle inspired design.

Two sizes: Regular and Long (Proto is the long version)
Long size specs=
TTH: 24.6
Reach: 18.3
Stack: 24.2
HA: 65*
CS: 16.7-17.9 (min/max range of sliding dropouts and eccentric BB)
CS growth at sag: .25
CS growth max: .32
WB: 48.6 as currently configured
Frame weight: 8.7lbs
Bike weight as shown: 33.7lbs
180mm travel F&R

If I were to describe the ride in one word: Smooth

Between the vibration damping qualities of the frame, the big wheels and the superb fork/shock it rides butter smooth.

Pedal bob is minimal. I don't notice any torque induced bob, only a small amount of movement from the mass oscillation of my legs. Bikes I've ridden that have a similar pedaling feel would be the Intense VPP bikes and Canfield F1 Jedi. The DW link Pivot Phoenix has a firmer pedal feel for example. I was expecting more of single pivot feel like an Orange or Santa Cruz Bullit but with those you notice more reactivity from the drivetrain.

One of the nicer characteristics I have noticed (and others that have tried the bike) is the cornering feel. Some bikes feel too upright and won't lean in, while others tend to pull in too much. This bike initiates turn in freely and settles into the corner radius you choose and just stays there. It doesn't try to tip in further or straighten back up. Has that on-rails cornering feel that I really like.

What else do you guys want to know?
Yeah One more question. How do I get one? Sweet bike.
What is the head tube size?
 

Pslide

Turbo Monkey
One of the nicer characteristics I have noticed (and others that have tried the bike) is the cornering feel. Some bikes feel too upright and won't lean in, while others tend to pull in too much. This bike initiates turn in freely and settles into the corner radius you choose and just stays there. It doesn't try to tip in further or straighten back up. Has that on-rails cornering feel that I really like.

What else do you guys want to know?
I'd guess this is at last partly due to the 29er wheel size. I'm assuming you're ridden 29er trail bikes? They have very stable, predictable cornering characteristics in my experience.

Are those Paragon drops? Do you think they'll hold up to DH abuse? Seems like a lot of force traveling through some small pieces...

The weight is impressive! There is a lot to love here...can't wait to see what other good stuff you have up your sleeve!
 

VELOMECH

Chimp
Jun 15, 2012
18
0
All Tig welded
Production bikes will have a 44mm head tube (to be single crown friendly)
Tube diameters are 3/4, 1-1/4 and 1-1/2. All the 1-1/4 tubes will go to 1-3/8 only to get rid of the funky 30.0 seatpost size and go to a 31.6 Chassis flex feels spot on (for my tastes) but I don't know how crash resistant it is. I want to get more ride time on it before I punish it.
 

VELOMECH

Chimp
Jun 15, 2012
18
0
I've been riding 29ers for eleven years. And yes, the cornering feel is definitely a component of the 29" wheel size.

Yes, paragon drops. 17-4 stainless is tough stuff. I'm not worried about them. But there are people that can break anything. Sometimes I stand in bewilderment of the stuff people drag into my shop broken. This bike is not for hucking your carcass off hillsides. This is for the rider that pilots the trails like a race car driver.

I'd guess this is at last partly due to the 29er wheel size. I'm assuming you're ridden 29er trail bikes? They have very stable, predictable cornering characteristics in my experience.

Are those Paragon drops? Do you think they'll hold up to DH abuse? Seems like a lot of force traveling through some small pieces...

The weight is impressive! There is a lot to love here...can't wait to see what other good stuff you have up your sleeve!
 

norbar

Turbo Monkey
Jun 7, 2007
9,988
542
Warsaw :/
I've been riding 29ers for eleven years. And yes, the cornering feel is definitely a component of the 29" wheel size.

Yes, paragon drops. 17-4 stainless is tough stuff. I'm not worried about them. But there are people that can break anything. Sometimes I stand in bewilderment of the stuff people drag into my shop broken. This bike is not for hucking your carcass off hillsides. This is for the rider that pilots the trails like a race car driver.
Yes but some extra beef for that once in a month case is quite useful ;)

I really like the design and the looks. One thing makes me wonder - the current specs are for size large? Because the wb seems pretty long for that ha and cs.
 

HAB

Chelsea from Seattle
Apr 28, 2007
11,087
1,381
Seattle
I really like the design and the looks. One thing makes me wonder - the current specs are for size large? Because the wb seems pretty long for that ha and cs.
Did you see the reach? That's one biiiig bike. I very understand wanting to make a bike that fits you well (I'm the shortest guy out of 11 on my dad's entire side of the family at 6' tall, so seeing them not fit anything gives me an appreciation for the plight of wookie sized people) but I have to wonder how much of the potential market you're sizing yourself out of by making only two sizes, with one of them being that big. I know I'd want something a good bit smaller, and I'm not exactly short. Of course you should make that large size if that's what you need, and it's great that someone's offering bikes for super tall people but maybe a third size would be a good idea? Of course that's more tube sizes to figure out and an additional jig setup, etc, so I understand if it's just too much to handle at this stage. Have you figured out what the reach is going to be on the smaller size? If it's something I could ride I'm very interested.
 

RD3

Monkey
Nov 30, 2003
661
13
PA
I probably wouldn't use the Paragon sliders on the production bikes. Too much leverage and not enough surface area. Fine on xc, but could be an issue for dh. You could make some hooded sliders by using a section of stock rectangular / oval tubing with a welded back plate and have the axle go directly through it.

Your seat mast has a lot of downward force on it for just one tube. I see you have it sleeved at the base, but would consider an additional tube to triangulate it.

Like the clean lines of the design.
 

VELOMECH

Chimp
Jun 15, 2012
18
0
Regarding the structural questions raised, I hear ya. From an intuitive design perspective, it is a struggle to have faith in these materials. Every day we see bikes made out of lightweight, low strength materials. To build a bike out of heavyweight, high strength materials requires a whole different perspective.

One designer that had an influence on the way I look at things is Colin Chapman (Lotus Race Cars) When everyone in the industry was adding horsepower, he was "adding lightness". I once read that Chapman would incrementally subtract frame members from his cars until something broke, then he would add in the last piece he removed. I doubt this is literally true, but the design philosophy is certainly his style. If you overbuild something, you won't know where the excess strength is. All you can do is guess at where you can make things lighter. If you under-build, you are more likely to find the week points, and then you can add strength just where it is needed. That is how people built winning race cars on small budgets back in the day.

Check out this link to see a race car that was very successful while being built on a small budget and creative use of materials:

http://www.classicoldcars.info/classic-car-reviews/maserati-tipo-6061-birdcage-motor-sport-icon/
 
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VELOMECH

Chimp
Jun 15, 2012
18
0
Yesterdays photo session. We did not have much luck with the light, but we still got a few sweet shots.

_MG_0008.jpg_MG_0047.jpg
 

tacubaya

Monkey
Dec 19, 2009
708
71
Mexico City
Regarding the structural questions raised, I hear ya. From an intuitive design perspective, it is a struggle to have faith in these materials. Every day we see bikes made out of lightweight, low strength materials. To build a bike out of heavyweight, high strength materials requires a whole different perspective.

One designer that had an influence on the way I look at things is Colin Chapman (Lotus Race Cars) When everyone in the industry was adding horsepower, he was "adding lightness". I once read that Chapman would incrementally subtract frame members from his cars until something broke, then he would add in the last piece he removed. I doubt this is literally true, but the design philosophy is certainly his style. If you overbuild something, you won't know where the excess strength is. All you can do is guess at where you can make things lighter. If you under-build, you are more likely to find the week points, and then you can add strength just where it is needed. That is how people built winning race cars on small budgets back in the day.

Check out this link to see a race car that was very successful while being built on a small budget and creative use of materials:

http://www.classicoldcars.info/classic-car-reviews/maserati-tipo-6061-birdcage-motor-sport-icon/
Colin Chapman built chassis insanely light and tested them out. Then if something broke, he fixed it and tested it again and again until he was satisfied. Then he knew he had the lightest design that could handle normal operating conditions and nothing more. He hated overbuilding.
 

norbar

Turbo Monkey
Jun 7, 2007
9,988
542
Warsaw :/
Colin Chapman built chassis insanely light and tested them out. Then if something broke, he fixed it and tested it again and again until he was satisfied. Then he knew he had the lightest design that could handle normal operating conditions and nothing more. He hated overbuilding.
It is good the problem with testing a bike is that you need more than one tester as he will never weed out the problems. I really like the way banshee does it test programs. It makes sure that even the biggest hacks wont kill the bike.