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PIC: BJs Work in Progress

1K views 17 replies 9 participants last post by  ScaryJerry 
#1 ·
ive allways wanted a nice looking bike:

with a nice low seat that doesnt get in the way (tricks etc the usual reasons)...
that can take a 24" rear wheel (larger sizes a 26")
a simple yet unique suspension design (that isnt a 4 bar linkage or a single pivot design yet works as well as them)...
a unique chainguide that comes built into the frame (like what the canfield bros thought up)...
a frame that can run a 9.0"x3.0" stroke 6-way swinger with a remote reseviour that also had somewhere to put it...
a headtube that can take a wide variety of forks without having to fiddle to much with crowns on forks...
a frame built for a 888r...
a frame that has a tough looking rear swing arm that isnt thin or rounded (something i hate about my ruckus and many other bikes at the moment)...
a long wheel base for racing...
a frame that fits lil old me (the right geometry and size coz im smallish)...
oh and a nice looking pressed metal badge on the headtube like what cars have...

so i designed one...:D

ive been sitting here looking at it for a while wondering what ppl whould think of it...and seems as MTBR has many many well educated ppl...that know what they like and are comsumers themselves i thought of posting it... :confused:

so what to u ppl think of it...i saw someones design of a bike a couple of days ago and saw all the crisicism it got (i want to see what u ppl think so by all means dont go easy on me :D )...but ill clear a couple of things up aswell...it may look like other bikes (things allways have similarities to other things :rolleyes: ) but thats just the way things are...im going to begin using programs to see how the suspension will peform and im hoping 8-10" of rear travel and i also reckon im gunna have to change the postioning of the linkages and the angles of them and probably have to make some minor changes to the shape and angle of the rear swing arm (probably bring it in closer to the frame)...but for the first version and a hand drawn picutre it will do...

the majority of things are to scale...and yes i realise the rear shock has no spring...i couldnt be f-cked wasting 30min trying to draw one thats to scale...

so anyone have any suggestions...

once i see how the suspension peforms then if its decent enough ill consider building it but for the mean time shes still on the drawing board...

so is she nice or is she horrible...

(and if someone can guess every bike i took insperation from...ull get a prize)

oh...and do u ppl think the chain guide will interfear with gear shifting... :confused:
 

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#4 ·
Looks like a mixture of Canfield/Cortina and SC's VPP. I like it though. Like snowskilz said it looks like the top linkage plate will hit the seattube. Try moving the pivot on the frame up a bit more so that it can cycle through the travel without hitting it. Then again I dont kno much about engineering so tha tmay or may not completely change the frame. lol. Good start though. :)
 
#5 · (Edited)
BJ ,you are a big cheater...
That thing is an 05 V-10 in esteroides...come on man... don't cheat like that..
 

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#7 ·
Beau said:
That headtube looks sketchy. I would say stick to posting on MTBR and leave the engineering to the pro's.

Beau
Hey man atleast he trying. give someone a chance. yeah its not perfect it may not work, but he tried. Have you suceeded at every single thing you have ever tried... i doubt it. Just think of how many times you've bailed off your bike. BJ is gonna prolly have to revise his drawing 3 or 4 times before it gets somewhere. but ya know what. atleast hes not robbin your house
 
#8 ·
I'm just saying.......

There is a lot more that goes into building a bike than simply drawing it up and deciding what material to use. How 'bout making the jig that will hold it first. Or, what type of welder to use and how you plan on treating the material when it is finished?

Good luck to him though.

Oh, and try robbing my house, I don't call 911 (click-click...BOOM hahahahahahahahaha)

Beau
 
#10 ·
BJ dont..

listen to angry old farts like beau who have nothing better to do. I think its a cool design and it looks cool. Although its a little vppish its still lookin good. Keep fine tuning it and it should turn out sweet. And beau why don't you show BJ the same kharma that most people show you when u put one of your odd recycled bike things on this board. Hes just a board kid in the summer trying something new. Its not like hes going to be putting his bike into actual production so just chill out and go buy a corvette or something.
 
#11 ·
i didn't feel like posting anything on this one just because i'd rather let some of the other engineers out there take care of it, but no one else did so i decided i'd step in.

first off, your linkage has too many links. look at a V10 or Canfield that you're trying to copy. they have two links between the rear triangle and the rear swingarm, one at the top, one at the bottom. yours has three, one at the top, two in succession at the bottom. your linkage won't activate the shock when it cycles through it's travel.

second, go out and build a hardtail, then worry about designing and building a full suspension bike. linkages are WACK, and you surely won't get them on your first try. you also need access to a lot of CNC equipment to mill out your small parts. familiarize yourself with CAD programs. all of them. and take some metallurgy classes. all of them.

third, monocoque and hydroformed aluminum are the most expensive, insane, difficult things to produce. molds cost thousands of millions of billions of dollars to make. you don't want to shell out that much for a one run custom bike. think basic steel tubing. it's cheap and simple to weld together.

fourth, your linkage design and placement needs a lot of work. whoever said whatever about stuff hitting your seat tube was right. also, the leverage ratios appear to be very very high. you'd be getting 9-10 inches of travel (assuming you weren't bonking your ass on the links), but the stroke on your shock would be quite small, not 3 inches like you specced on your wishlist. you want to be looking at a 3:1 ratio, 9 inches of rear wheel travel, 3 inch stroke on your shock of choice (make it fit an Avalanche shock, way better than a 6-way).

i think that's everything i can think of that you oughta know. if you have any questions about anything else about stuff and junk and things, page me or Zedro, he's way smarter than i am.
 
#12 ·
Check it.........

I was just dishin' out a little of the same kharma I recieved from him. It's all in good fun!!

http://forums.mtbr.com/showthread.php?t=33867

First reply. That's why, I just wanted a bit o' sweet revenge!!

BTW, I hate Corvettes and any other american car on the road. Maybe I could make one out of recycled bike parts...?....hum??

That is all, Beau

Oh wait......is 23 old?
 
#13 ·
Beau...dont sweat it man...i hate u behind ur back to...:D

anyways thanks for the feedback guys...it helps...although i am a lil dissapointed zedro hasnt cut it to pieces yet... :(

and VIA...i couldnt help it...the new V10 looks so sweet i had to make it similar in some ways...:D

and yeh i was thinking about the top linlage and u guys are right...so ill fix that one...

thanks scarry jerry i will PM u guys when i run into some problems...:D

i think i will fit it to an avalance then...and im gunna re-do the rear triangle...and re-think the linkages...

thanks again...:D
 
#14 ·
hmm. i know nothing about the fine art of suspension design, but i got 2 things:

move the resevoir to the gap inbetween the middle of the frame, or make the seat tube longer so it can be there. chainstay resevoir just seems like an accident waiting to happen.

and the indentations or whatever at the seat tube and head tube look dumb and look like they would weaken those two vital parts. just make it solid there.

other than that it looks solid. now get that thing into CAD or something and work on the suspension design
 
#15 ·
i was waiting for somone to come up with that or maby something to do with upsrung weight form the reseviour being on the rear triangle or some crap...anyway...

i would most indefinatly make a chainstay protector for the top and bottem piece of the rear trangle and it would cover the resevoir and the tubing...

CAD will be the next step after i fix some porblems first...probably gunna take a while tho...

also i was wondering...the wheel base is 45" inches...and the therotretical top tube is 20" the actual top tube length is about 16"...so does anyone think that the bike would be inballanced...i didnt...
 
#16 ·
BJ- said:
i was waiting for somone to come up with that or maby something to do with upsrung weight form the reseviour being on the rear triangle or some crap...anyway...

i would most indefinatly make a chainstay protector for the top and bottem piece of the rear trangle and it would cover the resevoir and the tubing...

CAD will be the next step after i fix some porblems first...probably gunna take a while tho...

also i was wondering...the wheel base is 45" inches...and the therotretical top tube is 20" the actual top tube length is about 16"...so does anyone think that the bike would be inballanced...i didnt...
i like your design man, keep workin on it and make it a lil tighter and you'll be fine.

The weight will be real low in the frame giving you a perfectly balanced feel i.e. v10. Where as a mono the CG is kinda below your ass so it feels different.
And the vp free the weight is under your nuts.

pick what feels best to you and run with it
 
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