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How many of you would rock this frame?

RideRMB

Monkey
Aug 29, 2007
395
0
'Da Hood
This is a future thing I'd like to do sometime in a while.

It's a DH frame with 9-12 inches depending on the final geo/ mount positions.

64.7 degree HT
83mm BB
150mm Spacing
1.5 Headtube
I'd have it equipped with a Floating brake but I don't know how it'd fit/ work.

NOTE: The rearward shock compresses first, then the whole section mounted to the frame pivots like a regular Stinky.


 

Transcend

My Nuts Are Flat
Apr 18, 2002
18,045
0
Towing the party line.
That is the most absurd thing I have seen this week.

12" of travel is just stupid.

Also, how is a 12" travel bike that will weigh a ton and not be very maneuverable a "new england racer"?
 

ZHendo

Turbo Monkey
Oct 29, 2006
1,571
44
PNW
i wouldn't for a few reasons:
-heavy because of all the linkage and 2 shocks
-2 shocks makes everything that much more complicated, you'd need to tune it so the first shock would smoothly transition to the next shock, and 12" of travel?
-it would have like 20 inch chainstays
 

Lollapalooza

Monkey
Jan 22, 2007
527
0
You're going to need ridiculously long stays with the shock mounted there. Check out 2 stage bikes. They have it dialed pretty well.
 

CrabJoe StretchPants

Reincarnated Crab Walking Head Spinning Bruce Dick
Nov 30, 2003
11,569
422
Groton, MA
I was going to calculate the DOFs of that thing, got a piece of paper, looked at it again, got vertigo, puked in my bucket and left the thread.

That bottom "scissor link" doesn't need to be there either, with the right coupler curves it could be one solid link.
 

norbar

Turbo Monkey
Jun 7, 2007
9,564
345
Warsaw :/
Well 2stage 2shock stuff actually gets a lot of good results in nz and aus and it's not that hard to set it up. Plus the weight is not insane.

But still i don't get the idea of 9-12 inches of travel. 7-9 is sufficent mostly plus why do you need 2 shocks in your case? What's the advantage?
 

jcook90

Turbo Monkey
Mar 3, 2006
1,211
0
Connecticut
You can get the same result of having those 2 shocks, one set up softer than the other, with a really progressive linkage.
 

w00dy

In heaven there is no beer
Jun 18, 2004
3,412
28
that's why we drink it here
Nice effort, but there's a few things to consider. The first one is chain stretch. That would have a very rearward axle path and the thing wouldn't pedal very well over bumps. Second big thing is the double shock bit. There are a few companies out there with such a thing, but the shocks control wheel travel in different directions. It looks as if both pivot points serve to move the wheel in the same direction. If you're going to add a second shock and all the complexity that comes with it, make sure it's justified. 12 inches of travel is overkill for racing, but the other specs you've got there make sense.
Don't get discouraged, you're taking interest in this at a young age so you've got a head start on nearly everyone.
Don't take Trans(conde)cend too seriously. He's known for his harsh tone.
 

jonKranked

Press Button, Receive Stupid
Nov 10, 2005
55,815
4,759
media blackout
Nice effort, but there's a few things to consider. The first one is chain stretch. That would have a very rearward axle path and the thing wouldn't pedal very well over bumps. Second big thing is the double shock bit. There are a few companies out there with such a thing, but the shocks control wheel travel in different directions. It looks as if both pivot points serve to move the wheel in the same direction. If you're going to add a second shock and all the complexity that comes with it, make sure it's justified. 12 inches of travel is overkill for racing, but the other specs you've got there make sense.
Don't get discouraged, you're taking interest in this at a young age so you've got a head start on nearly everyone.
Don't take Trans(conde)cend too seriously. He's known for his harsh tone.
Transcend hates ViciousDHer :(
 

Stray_cat

Monkey
Nov 13, 2007
460
0
Providence
Nice effort, but there's a few things to consider. The first one is chain stretch. That would have a very rearward axle path and the thing wouldn't pedal very well over bumps. Second big thing is the double shock bit. There are a few companies out there with such a thing, but the shocks control wheel travel in different directions. It looks as if both pivot points serve to move the wheel in the same direction. If you're going to add a second shock and all the complexity that comes with it, make sure it's justified. 12 inches of travel is overkill for racing, but the other specs you've got there make sense.
Don't get discouraged, you're taking interest in this at a young age so you've got a head start on nearly everyone.
Don't take Trans(conde)cend too seriously. He's known for his harsh tone.
Couldn't agree more.

It's awesome that your starting to work at this stuff young, but starting on a multi-shock-complexity-machine, is a really hard place to start. Try interpreting a more tried-and-true design to your own liking. I think it'd be a more beneficial learning tool. Good luck!
 

chriscarleton

Monkey
Aug 4, 2007
366
0
Portland Maine
I tell you although I'm not sure whether your gonna say I'm skilled or stupid for my age, 13. BTW I'm right down the road from you!
I was going to say you were a fool, but I kind of feel like a dink now, because when I was 13, there was really no internet message boards to post on, but I was drawing ridiculous frame designs like this in my study hall thinking that I came up with the next FSR linkage or some BS.

With that being said, if you are serious about designing bikes, take some engineering and physics courses and all that jazz.
 

ROTFLMAO

Monkey
Nov 17, 2007
363
0
Maumee, Ohio
See my user name.

Seriously though, I did this kind of stuff when I was 13. If you're serious start reading up on suspension designs and how/why they work. Take some mechanical design classes. See where it leads you.
 

FCLinder

Turbo Monkey
Mar 6, 2002
4,403
0
Greenville, South Carolina
RideRMB, you are going to get a lot of crap said to you for your design. Mainly because you ask how many people would Rock Your Frame design without it to be a proven DH design. I have to say you may want to think again on the design concept. It’s good to see more people these days dreaming up newer designs. My thoughts are rethink up your design and then ask people what they think or their input to help make it a better design or in your case a design that would work in real Downhill situations.
Don’t give up man!!!!!!
 

jmvar

Monkey
Aug 16, 2002
414
0
"It was a funny angle!"
Pick up a book on Integrated design processes and read a little bit. It will teach you to think about problems, in this case with bicycle design, and show you techniques on how to come up with solutions.

What is it about todays DH bike that is lacking? What would you (or the market) like to see in a design and characteristics of the bike?

Cool that you are thinking about this at a young age, keep it up. Try to see if you can do a project at school where you design something in your shop class.

We had a course in college where the students would design a bike out of PVC. Cheap, easy to make changes, and a great way to get your foot in the door for mechanical design.

BTW...stop using your design papers as table mats...get a design notebook!!!!!
 

LMC

Monkey
Dec 10, 2006
683
0
i think it has potential but just needs refined somewhat.

2 air shocks is not a bad idea, it could be used to have say 8-9 inches of travel using a 2:1 travel ratio and of course they can be independantly tuned by altering air volume to produce a more progressive/linear ride. kind of like the Foes 2:1 bike with the dual rate spring does.

if i were you i would re draw the frame removing the paralel linkages that the rear pivot about and replace it with a single pivot. also reduce the travel to a more race worthy amount.

Its an admirable 1st attempt i think.. especially considering your age..
if you are serious about wanting to actually make this, get a copy of solid edge/ solidworks and teach yourself how to construct the shapes needed to create the frame. the functions you will need are not hard at all to learn.

a copy of linkage would be handy too.
 

ÆX

Turbo Monkey
Sep 8, 2001
4,921
0
amarillo
i think it has potential but just needs refined somewhat.

2 air shocks is not a bad idea, it could be used to have say 8-9 inches of travel using a 2:1 travel ratio and of course they can be independantly tuned by altering air volume to produce a more progressive/linear ride. kind of like the Foes 2:1 bike with the dual rate spring does.

if i were you i would re draw the frame removing the paralel linkages that the rear pivot about and replace it with a single pivot. also reduce the travel to a more race worthy amount.

Its an admirable 1st attempt i think.. especially considering your age.
.
if you are serious about wanting to actually make this, get a copy of solid edge/ solidworks and teach yourself how to construct the shapes needed to create the frame. the functions you will need are not hard at all to learn.

a copy of linkage would be handy too.
me to , keep at it man, what else is there to do with 2' of
snow on the ground. pm me for solidworks
 

Super-man

Chimp
Jun 20, 2005
56
0
Orem, UT
Not sure if it's the best design, but don't let anyone discourage you. Keep at it and try some new drafts. Perfect that sucker.

2 shocks doesn't make sense to me either.
 

RideRMB

Monkey
Aug 29, 2007
395
0
'Da Hood
The whole idea is that one shock can be really soft for small/medium bumps and the longer shock is more stiff for big bumps/ bottom out forces.
 

Bldr_DH

Monkey
Aug 8, 2003
767
0
NO BO CO
Based on the current suspension technology, you really won't be needing independent small/large bump absorbing shocks.

I used to do the exact same thing as you -- experiment with designing crazy suspension linkages. The thing you will soon learn is that anything overly-complicated is generally bad. More moving parts, more places for things to go wrong. The next revolutionary suspension design isn't likely to have fifteen linkage plates, three shocks, and so forth -- It will simply be a highly refined version of something already out there. Take the DW Link for example. Tons of other companies have essentially created the same linkage design (look a the old Balfa 2-steps, or an old Canondale) where the rear triangle suspended by two small links from the front triangle. DW simply found (rather, created after a lot of calculation and experimentation) a better implementation of that design.

With that said, it's never a bad thing to think outside of the box, so keep with it!
 

Ithnu

Monkey
Jul 16, 2007
965
0
Denver
I'd take it for a ride. Do you have any more thoughts than a quick sketch?

Ahhh, I just saw that you're 13. You've got the right idea, you want progressive suspension. But now that's being accomplished with changing leverage.

That doesn't mean you still shouldn't keep coming up with ideas, I've seen what seemed like dumb ideas turn out to actually work when you look at all of them and take the high points of each.
 

OGRipper

Turbo Monkey
Feb 3, 2004
9,724
160
NORCAL is the hizzle
I think it's got some problems but it's pretty cool to come up with something like that and get it on paper. As you learn more and perhaps eventually actually make frames, I suggest you keep in mind two very important rules: (1) Keep it simple; and (2) Different is not always better.
 

ÆX

Turbo Monkey
Sep 8, 2001
4,921
0
amarillo
The whole idea is that one shock can be really soft for small/medium bumps and the longer shock is more stiff for big bumps/ bottom out forces.
another great thing about two shocks is a super low leverage ratio.
making using air shocks that are availible now w/o over heating them.
the two shock bike i made they were diff and was hard to tune.
i would try and keep the ratio the same on both.

also makes a good freeride layout b/c you can lock out one
and instantlly reduce your travel by half for xc stuff.

alex
 

khoolhandz

Chimp
Jul 27, 2006
89
0
I LOVE SURREY
I'm sure if DW came up with that linkage, everyone here would be ogling on it.

Don't let these clowns here discourage you, in theory your linkage may work.

Would I rock it? NO. Would I want to try it? Heck ya.