Help on Custom Sub Frame

[zx12argh]

Hey Guys,

For the next stage of my build prior to respray I am looking to redesign my rear end. No fat jokes.

The biggest constraint of a zx12r is the big chunky box subframe. I think the nips are expecting sumos to ride these bikes considering the size and shape of them.

Can someone let me know the deal with making up my own subframe and getting it engineered - particularly in brisbane.

I can do my own design and load calcs - I may be able to persaude kroosn to weld the thing for me - but for legality issues what else needs to be done? Expected cost? Who to go to?

Cheers fellas - have yourselves a good weekend!:D

Is the sub-frame welded or bolt-on?

The GPz9 is bolt-on and therefore isn't considered part of the frame for engineering purposes, I can pretty much do whatever I like to it.

[jakam04]

awesome point to know... thanks Chalky lol... mines bolt on too...

Jarrod

Kawasaki mate, they think of everything

[Hillsy]

Yeah - that is interesting Chalky.

Hey Pete - are you considering building your own subframe and tailpiece? That's going to be a pretty expensive exercise if you're getting someone else to do it, I'd imagine (although original and unique and I encourage you to do it!).

It seems the easiest is to source a complete sub-frame and tail piece off another bike (R1, R6, Gixxer6, whatever) and mod the mounts to suit. My 2c worth.

Keep us posted and pics please!!

[Gix11]

Mine is fabricated from steel box section and then we welded lugs onto the original ali frame to accept the new bolt on method (it was originally wleded). Yea, it may be heavier, but I ain't Rossi and don't give a shit. Used steel as it's easier to weld and cheaper. If you're good with a Tig welding go for the ali box section for a few extra dollars. Remember, this ain't an easy job, but if you're an engineer you should be able to get it right. Be prepared for a lot of swearing though.

[WATEVR]

hey pete what sort of tail are you looking to put on it? do you have heaps of stuff attached to the sub frame like fuse box and other stuff as i seem to have lots on the zx7r

[fimpBIKES]

um, think again chalky
i was told otherwise



but i would GLADLY be corrected!!!

[fimpBIKES]

oh yeah, im using pretty chunky steel too

that is until i am happy with the design
then will probably go to some kind of ally setup

[kroosn]

come on pete solidworks up your idea. your pro at it now arent you. im sure it will need some screws. but vote is either chop the original or replace it with one off something else.i have a sub frame on the ts out the back pete, lol. call the wreckers or steal one off a pocket bike like some people do.

Kroosn

[Tony Nitrous]

Im doing a rear-end swop later in the year on mine too.
Possible Late SV650 or GSXR1000.

Going to use a complete factory rear end so that I can
swop between single seat cowl or pillion seat, I get decent
rear lights not El-Crappo aftermarket, pillion pegs, seat lock
and can probabley use an aftermarket undertray to suit the donor.
...and its a good oppertunity to raise the rear slightly.

Things to consider....
Modifiy subframe mounts,
Seat to be butchered/re-upholstered to fit back of tank,
Re-do Exhaust hangers,
Will any new bodywork blend in / miss match,
remounting of any electrics on current undertray/rear end,
remount rear brake reservior,
and probabley lots of shit i haven't thought of yet!

[fimpBIKES]

pffft, solidworks
bunch of amateurs [:P]




gimme autodesk inventor anyday!!
http://www.streetfighters.com.au/forum/upload/71496192749219.jpg


:D

quote:Originally posted by fimpBIKES

um, think again chalky
i was told otherwise



but i would GLADLY be corrected!!!


That's what I was told, on here (?), by someone going through it at the time. It was about the time I bought the GPz9, and was quite chuffed to find that out

[fimpBIKES]

ben??

[Iceman]

I made my own sub frame, got my mate Paul to finish off the welds as I don't structually trust mine. It's amazing what you can do with an angle grinder, welder and half a dozen stubbies.

[chopaweeza]

According to the Engineer we in the Chopper Builders recommend a bolt on subframe has to be engineered in NSW . The reasoning was - because it supports the weight of the rider & pillion , has to extend & cover the rear wheel(via the mudguard)and support the rear ADR specified safety equipment(tail light & blinkers). He hasn't steered me wrong so far and I have heard several times of people being defected by the RTA for not having an Engineered subframe or having a modified subframe on their bikes. But, getting a subframe engineered is usually only $3-400 depending on what is actually done. If you want a smooth run through Engineers on this get the modification done by someone like Ben Shaw and produce the receipt when you get it passed. Another way is to take photo's of the work as it's being done to show good technique on welds & such before the paint has been laid. Makes it easier for the Engineer to pass it that way if they think that the paint isn't hiding dodgy welding or engineering.

[zx12argh]

quote:Originally posted by WATEVR

hey pete what sort of tail are you looking to put on it? do you have heaps of stuff attached to the sub frame like fuse box and other stuff as i seem to have lots on the zx7r


I plan on making my own subframe but grabbing a tailpiece of something else and making it stubby severly chopping it and remodeling- possibly having the exhausts extend out past the tail piece. Anyone here have access to a lathe and a bit of billet to make new endcaps for my exhuasts?


quote:Originally posted by fimpBIKES
pffft, solidworks
bunch of amateurs


Mate when I get solidworks reinstalled on my home PC (genuine copy I swear sir!!) I'll certainly be throwing down the 3d design challenge matey ;)

Hey Tony - I've considered most of those but because of all the work gone into raising the tail to where it is now most of it is already done... though will have to find a replacement seat unit that will work and am expecting that to be a challenge...

and chalky vs fimp all I can say is please please please let it be so... Hey EXBEN take a break from building your beastie and come give me your two bobs worth [8D]

[EXBEN]

quote:chopaweeza Posted - 17 Feb 2007 : 09:01:22
--------------------------------------------------------------------------------
According to the Engineer we in the Chopper Builders recommend a bolt on subframe has to be engineered in NSW . The reasoning was - because it supports the weight of the rider & pillion , has to extend & cover the rear wheel(via the mudguard)and support the rear ADR specified safety equipment(tail light & blinkers). He hasn't steered me wrong so far and I have heard several times of people being defected by the RTA for not having an Engineered subframe or having a modified subframe on their bikes. But, getting a subframe engineered is usually only $3-400 depending on what is actually done. If you want a smooth run through Engineers on this get the modification done by someone like Ben Shaw and produce the receipt when you get it passed. Another way is to take photo's of the work as it's being done to show good technique on welds & such before the paint has been laid. Makes it easier for the Engineer to pass it that way if they think that the paint isn't hiding dodgy welding or engineering.

Yeah wot he said^^
There is some grey areas tho;)

[zx12argh]

Thanks ben - that makes perfect sense. :D

Now... can anyone here in brissy recommend an engineer?

[fimpBIKES]

i have also found that it is best to go to the engineer with sketchs and drawings
BEFORE you actually do any work

that way they are happy that they have had some input

and definitely take a lot of pics



only worry i have is that IF i was to get my subframe engineered my bike would become complied for single seat only
so i think i will give it a miss and swap it back if i ever get pulled up ;)

[fimpBIKES]

dave kellet in brissie is meant to be a bit of a chassis guru


yeah, solidworks VS inventor
who cares, they all do the same shit anyways
oh and they now both have VERY handy inbuild tools for building space-frames
which is pretty sweet


and tony is onto something there
if you arent using a miniture tail piece than its a stack easier to hack up a spare standard subframe

mines too skinny/short
so have to go custom, what a pity :D

[shift1313]

im with fimp. i use inventor 10 and i do this stuff for a living. I also use ugs nx which is pretty powerful. Actual design of a sub frame isnt hard because for all intensive purposes they are triangles. Unless you are trying to do something radical you would almost be better modifying something. it sounds like you guys are really restricted over there. One thing that might be an option is mod your stock unit to bolt on and then whatever unit you decide to bolt on in the same location, just incase you have to swap back.
Good luck with what you decide,

quote:Originally posted by fimpBIKES


swap it back if i ever get pulled up ;)


Do you really think you're average plod would pick up on the different sub frame?

Just tell'em it's only the plastics that have changed.

[WATEVR]

geez im with chalk who the f@#k is going to know that you done a conversion anyway?

[fimpBIKES]

well, given that my body work finishes WAY before the rear wheel
and it sticks up vertically with two big horn shaped thingies i am expecting my fair share of attention...



shift, i just got upgraded to inventor pro 11
score a few bonus thingies like FEA and piping stuff

still need to figure out how to add custom sized tubing to the chassis generator
handy stuff indeed!

[fimpBIKES]

oh and chalky
i have been pulled on group ride in NSW

and all the cops were looking for were non-standard pipes, worn tyres and cut-off mudflaps
[xx(]

gotta love nsw, the cops pull up 20+ bikers in the name of safety
but let ricers fly straight past...

quote:Originally posted by fimpBIKES

well, given that my body work finishes WAY before the rear wheel
and it sticks up vertically with two big horn shaped thingies i am expecting my fair share of attention...



shift, i just got upgraded to inventor pro 11
score a few bonus thingies like FEA and piping stuff

still need to figure out how to add custom sized tubing to the chassis generator
handy stuff indeed!


Guess you'll be knocking out Spondon replica frame designs in no time then Fimp. Find a welder, and a tube bender, and you'll have a ready market mate.

[fimpBIKES]

already have both at my disposal mate, but i thought i might just tidy up a few loose ends first!! ;)



ps- if only the software had a "jig" generator!!!

quote:Originally posted by fimpBIKES


ps- if only the software had a "jig" generator!!!


Aaah just free-form it mate, she'll be right :D

[fimpBIKES]

hahaha, yeah

"what could possibly go wrong"

(how about that on a shirt???)

<center>Angle Grinder - Check
Welder - Check
Jig - Naaah
Just Free Form It
She'll Be Right</center>

[shift1313]

quote:Originally posted by fimpBIKES

well, given that my body work finishes WAY before the rear wheel
and it sticks up vertically with two big horn shaped thingies i am expecting my fair share of attention...



shift, i just got upgraded to inventor pro 11
score a few bonus thingies like FEA and piping stuff

still need to figure out how to add custom sized tubing to the chassis generator
handy stuff indeed!


my copy of 10 has fea and piping generator. Do you use the sheetmetal stuff often? its really cool being able to generate it in 3d then lay it flat on the program.

[sharky]

I use old cornflakes packets and fold 'em up.....[:o)]

[fimpBIKES]

yeah, we do a fair bit of sheet metal stuff at work

i find it handy for myself at home (just print out a template, glue it on and bend/jigsaw it out)
but the guys on the press at work are pretty damn good
generally just put maximum dimensions and critical hole centres on and they sort it out ;)



im with sharky on the cornflates thing though
bloody handy method that!!!!

[zx12argh]

Some preliminary sketches of my subframe. Investigating a mates fathers mate for the engineering certification.

Just want to get it all sweet so if a copper pulls me over there are no hassles - and I wouldn't mind getting it insured and not having to worry if they are going to try and void my contract when it comes time to claim.

http://www.streetfighters.com.au/forum/upload/8670357333949.jpg

http://www.streetfighters.com.au/forum/upload/8670357352251.jpg

http://www.streetfighters.com.au/forum/upload/8670357348550.jpg

[fimpBIKES]

isnt that kinda vertical?

[zx12argh]

yupp - the angle is a little off in that shot but its actuall pretty close to what I am expecting

deffinately need to tweak that angle - i've only taken measurements with a tape measure - not very accurate [:p]

[shift1313]

will it be strong enough? id be affraid to run plates that far with no intermediate bracing. the rear section where you have your reg/rec drawing is way stronger then the actual part you will sit on. Think about when you lean off the seat in a turn and you are side loading it, you have no structure in that direction. think long and hard about a good way to terminate those tubes into eachother as well.

can you post up a pic of your bike in here for reference.

[Gix11]

Here it is mate:

http://www.streetfighters.com.au/forum/upload/948630390118491.jpg

http://www.streetfighters.com.au/forum/upload/952870184124816.jpg

[shift1313]

do you know what tail is going on there? No offense but from the drawing i dont think it will look much different from stock, as far as what you can see. Maybe im missing something