Mountain Biking - My DH bike design

just tell anything to me....

For first:

Hmmm, with a little tweaking you could possibly get a better rear end. From the looks of it it looks to be a short stroke length shock. Also what sort of numbers are you thinking the rear end will push out and what kind of axel path.

Can't really be bothered analysing them properly sorry.

On the evolution it looks like the linkage will hit the shock. What am I missing on that?

I still dont like the foating BB........

On the evolution it appears there is extra linkage near the top of the shock, is all that actually necessary?

On the evolution-x, it just doens't look like it will always compress the way you have it pictured. What's to stop it from just pivoting on the chainstay/bb pivot and essentionally pulling on the shock? It seems to me that those two bottom bracket pivots would need to be farther apart horizontally to ensure that doesn't happen.

What does the axle path look like? Placing the shock in the front triangle would make more sense because it is easier to adjust/tune there.

The thing I dont like about the design is the floating BB. Say you are landing a jump. The Pedals move with the suspension and the shock is absorbed for the frame, but not the pedals. You would have to be sitting on the saddle for the suspension to absorb the shock for you. It kindof hard to explain but maybe someone understands.

What does the axle path look like?
Looks like it would be vertical to me.

I reckon the center of mass should be a bit lower...

It looks like a lot of pivot points. And would the saddle hit the rear tyre on full compression? Looks good though, I'm impressed.

What does the axle path look like? Placing the shock in the front triangle would make more sense because it is easier to adjust/tune there.

The thing I dont like about the design is the floating BB. Say you are landing a jump. The Pedals move with the suspension and the shock is absorbed for the frame, but not the pedals. You would have to be sitting on the saddle for the suspension to absorb the shock for you. It kindof hard to explain but maybe someone understands.

YEP its called chain suck and it Sux0Rs

now dont you ever wonder why bike designers are paid so much?

i will leave it at that

Here is the picture of the travel path, about the short travel shocks its true, the evolution using 70mm shock with 35mm travel, and the evolution-x using 200mm shocks with 60mm travel to get 250mm rear travel, about the floating bb, what can i say, i just try to minimize the chain growth with the system.
The extra linkage for the shocks at the evolution, with that i can use short travel shocks to get long travel rear wheel.

The travel path looks great. It must be super plush and rolls fast over bumps. The ONLY thing I dont like is the Floating BB. Otherwise the linkage is great.

wouldnt the leverage ratio be huge with a short travel shock and 250mm of travel ?
and with the evolution it really looks like it would pull on the shock if hit the right way...

look like good desings but need a little work, keep goin you got a good start.

I think you are asking your bike for another 400mm of chain at full compression. I would say you wont have that to spare and you wont get full suspension travel and/or you will snap chains or wreck your dropouts, derailuers ect. But its a fine attempt and worth persisting with, no design is right the first time. They all need to be drawn, studied, redrawn, built, tested, modified and tested some more before they are right. More power to you for giving it a go.

One other thing, there's a well known principle of engineering. Its called the K.I.S.S. principle. Keep It Simple Stupid. :D

Actualy, i don't have resources to build the prototype, so i can't test the design, i agree with the KISS principle too, but i try to get inovative with my design. I will be happy if any body out there want to bulid one, it's free to copy, distribute, modified, with the source offcourse :).

Any body out there have idea how to replace the floating BB to minimize the chain growth? Actualy i don't like floating BB too, but i don't get another simple and reasonable way to minimize the chain growth that come with the system :( .

My Deepest Apologies Man....

I see waaaay too many prints everyday @ work ..... I can't even look at another one.

Looks good @ at glance anyway.

Go for it if it feels right !!!!

I'd love to take it up but Iv'e got a shed full of projects already plus my last semester at Uni and the ongoing house restoration. If I start anymore projects my wife will kick me out so I'd need to be able to sleep under it. Keep at it, refine the concept and get a copy of mechanical desktop to help you refine it. Somebody will take you up on it.

Going to call the second one The Tuesday since it involves the DW link?

Rethink the design of the first one and you will have a nice DH/FR bike.

Thank's for everybody attention, here in the attachement i include drawing exchange dxg formatted cad file of the design in the zip archieves file, everybody ideas is welcome, you can edit and modify the design because of every body ideas is welcome.

You can see the movement, but not the chain growth, with the programs linkage, by opening the LTX file in the zip archives files with the programs. downloat it at http://www.extra.hu/linkage/linkage2.exe

now dont you ever wonder why bike designers are paid so much?

i will leave it at that

No I don't I sort of know 2. And the work they put in is incredible and requires some very specific skills.



Any body out there have idea how to replace the floating BB to minimize the chain growth? Actualy i don't like floating BB too, but i don't get another simple and reasonable way to minimize the chain growth that come with the system


There really isn't much. But a couple of companies have thought of using this type of idea and most people just aren't excepting.

Keep it up, looks like a good design but it isn't for me :)...

Detailed in graphics format.

Just came out with this concept to replace the floating BB on the Evolution-X

i have new design posted, see it at http://www.bikeforums.net/showthread.php?t=132675

feel free to build from the design. i post a 3d view for the evolution-x

oh dammm....

how did you draw all those individual nuts and bolts? and how did you get the lines to line up so perfectly and symmetrically? (i'm a 100% CAD NEWB)

Ok, whats this your 3rd design?, 4th?. Your going to have to bite the bullet and build one. You've being putting in some big hours on these, it cant just be a passing fancy. I use autocad if I absolutely have to, and I've got some idea how much work you've done. If you want someone from a frame shop to pay attention your going to have to put it in metal. When your prototyping you dont have to have perfect finish or even the final material types. You can build a geometry tester out of steel of any section provided the geometry is the same, this can make testing relatively cheap. Prove the principle then build the pretty frame in the final material to continue testing. You've come a long way, its time to go all the way.

Those look awesome. I like the details.

"If you build it, they will come"

harov3 is right. those look like they're ready to be pitched to a company.

nice design.. its quite rare that i come across people who want to build up their own bike starting from some metal tubes.. hope the project works well!

WHOA!!! The bb is on the linkage plate? In some weird way it reminds me of the faith. Its an interesting design but scares me to death. The faith doesn't look burly enough to handle much of anything.

Good luck though, I love seeing fresh designs. I love the shock plate, that thing looks tough :)

I notice you are trying to not interupt the seatube. Is this for seat extension or have you found the shock placement a little forward to be better? And trying to envision wheel movement at impact. It is going to move back and up? Not up and in correct?

Pretty nice design. The fact the entire bike is sitting on two linkage plates is my only concern but thats becuase of my size and how I ride :)

WHOA!!! The bb is on the linkage plate? In some weird way it reminds me of the faith. Its an interesting design but scares me to death. The faith doesn't look burly enough to handle much of anything.

you just gotta have some faith, ya kno?

oh dammm....

how did you draw all those individual nuts and bolts? and how did you get the lines to line up so perfectly and symmetrically? (i'm a 100% CAD NEWB)

i am using VariCAD (www.varicad.com) to draw 3D CAD, they have templates for parts like screw, bolts, skf bearings and others

i have this weird idea to make the prototype from woods for geometry tester?????

revision for the linkage at the axle parts

i have this weird idea to make the prototype from woods for geometry tester?????

revision for the linkage at the axle parts

Uhh...as long as you ride it! :D (Really bad idea, you will get splinters where there should never be splinters) :eek:

http://creativecommons.org/images/public/somerights20.png (http://creativecommons.org/licenses/by/2.5/)
This work is licensed under a Creative Commons Attribution 2.5 License (http://creativecommons.org/licenses/by/2.5/).

I have seen scaled versions made of wood. Heck even cardboard. Really gives a good feel for how the travel moves.

I think k'nex could give you a really good idea of how a design would work. And if it sucks junk it and start over. Just find some small springs to use as suspension.

www.bikechecker.com

I Post the ltx file here in the zip archive file for the program linkage.
For better leverage ratio for the evolution-x now with 230mm rear wheel
travel using 86mm strokes shocks

some details at the front triangle for 230 mm axle path evolution-x

dude pictures are nice and all but will you ever actually make it?

dude pictures are nice and all but will you ever actually make it?

I'm sory man the prototype never come out untill now

The fact that the BB travels in an arc means that you will have the potential for a massive suspension-induced load on the chain. Fix the BB!

Great drawings! I used to be a drafter so I really enjoyed looking at them. :) You could probably make a rideable prototype out of wood, but of course it would be heavy and not have enough strength to really test it. :D And don't bother using pine boards from Home Depot, try to find some ash or hickory. :lol:

(I've actually considered making a road bike frame out of wood. :o )

The fact that the BB travels in an arc means that you will have the potential for a massive suspension-induced load on the chain. Fix the BB!

how about my idea of using gearbox (http://www.bikeforums.net/attachment.php?attachmentid=35872).

my theory is, when put weight at the bb and hit a bump, the upper linkage will rotate clockwise with the center point at the front triangle, and the lower linkage will rotate clockwise with the center point at the rear triangle because of the weight we put at the bb work as counter force from the bumb. and comparing with theory the system will lock out, i think the system is lock when not hitting bumb or when climbing.

See the design galleries at www.geocities.com/r11ohm (http://www.geocities.com/r11ohm)

beast: looks neat, but overly-complicated.

evo: MAKE IT! the linkage kind of looks like a canf1