Bushmechanic frame Build pics and Stuff

80-90kgs sounds like fun....
but what about trying to get the balance point back far enough for the big ugly 4smoker in a 2smoke frame, may need a little more than 50mm on the headstock to try an lighten the front, and no the throttle does not count as a weight shifting device (coz sooner or later your guna haf to close it).

Im using a ktm 85sx because you get a full sized shock and nice 43mm forks, the rake is 24 deg, if I go to 30 the wheel base extends about 70mm, 120mm total extension at the front

Hi Bushmechanic
well done on what you are doing with the frame least you are having a crack. that 700 big block must be wicked fun
keep up the good work
cheers aquajett

cheers aquajett

gearbox broken again so more time for building stuff, I think im supposed to mow the lawn, paint the house or something

frame weight is at 7.5kgs so far but got a few little lugs and the subframe/airbox left to add so I guess it will be 9-10kgs. the stocker is just under 12kgs and the first one i modified ended up (15kgs, big boned)

adjustable top shock mount


husachopper mock up for Bergbro, exhaust will eventually be 2 into 1 right out of the head
pic is cut near in half :evil: click link to view full http://husaberg.org/forum/download/file.php?id=2809

it lives :twisted: :twisted:

went from 86kgs with 43kgs each wheel
click link for full pic

http://www.husaberg.org/forum/download/file.php?mode=view&id=2831


to 98kgs with brakes carb electrics water oil and 1Lfuel

download/file.php?id=2832



http://www.husaberg.org/forum/download/ ... ew&id=2833


rides good, turns way too easy does everything right so far, rear and rear of seat are up too high will drop it down and or lower the subframe.

rear wheel shows 50.5kgs and front 48kgs bit more stuff to add, tank maybe a sort of airbox and a rear guard should be about 102 kgs without fuel

It's a beauty!

not really beautiful yet perhaps but a bewdy maybe

the added trail and rake is awesome in the sand, I did all kinds of stupid stuff in the whoops today and didn't feel like the front was trying to kill me except when the seat kicked my butt, i gotta drop the subframe.

cradles nicer in rocking chassis movements partly due to the more harley rake that I feel is making the forks less prone to blowing through and without the bulky tank i can sit right up the front so front end corner grip is sensational

lofting the front is much easier, lower COG makes its tip resisatnce really low and loosing 15 kgs makes it go like a rocket

the nicer swingarm angle gives more traction and the chain pull moment does its anti squat thing mid corner with the power on, the roadbike guys aren't kidding when they say chain pull moment is at the centre of the motorcycle handling universe.

I love this thing, just like a new bike :twisted: :twisted:

its ended up

wheelbase 1570mm (1480 stock)
rake 31.5 degrees (27 stock)
trail about 150mm (about 110 stock)

swingarm pivot height both wheels on the ground 450mm (460 stock)
seat height 930-940mm with corrected subframe
ground clearance 320mm (380 stock)

wet weight but no tank or fuel 100kgs (say 115 stock)
and shed loads of 700 tourque

Hi Bushie,

great work, thank´s for letting us beeing part of the development

It´s not frame related, but i´ve seen an oil line from the filter -housing going to nowhere -
will you run an oil-cooler?

peter

Rocker pin oil line.
[attachment=0:29zoc2n5]IMGA0945.JPG[/attachment:29zoc2n5]

Fun project Bushie!
Brings warmth to my heart to see creative, and committed people! :cheers:
There is space for a down-drafted intake, isn't there? :wink:

I think that within 2 years "all" dirtbikes will have box frames to give space for a more effective shape of the intake port. Remeber where you heard it first!

its great fun building a bike, the more variables you can control the better so a ground up approach makes it very rewarding even though there is a lot more to do. total hours actually working not much but deciding what to do takes a lot of time at first, if I build a few more it should speed up that part of the process.

Gokai, Smorgy has it right yes its an oil line to feed the exhaust rocker pin. the only parts of the engine Ive ever really seen show premature signs of actual wear rather than just being smashed (gears) are the clutch steels (fixed with dimples) and the exhaust pin, the pin is stock with a 3mm hole in the middle , one end is plugged, I welded a plug in the oil hole in the rocker arm then drilled a 0.5mm hole through the soft plug, there is also a tiny hole directed at the exhaust valve stem. maybe a bit of overkill but I've noticed pin wear accelerate a little since I got my forks nice and stopped falling off all the time other guys have done this before, I just copied them. another reason I did the oil line is the little oil bath in the head that the cam runs in is canted forwards with the engine so it holds less oil. I intended to weld a strip of ally around the front of it to get some capacity back but I got all excited about going for a ride and hoped the oil feed squirter out the top of the rocker arm will be enough..... next time.

Dr-C thanks! encouragement appreciated :!: the perimiter frame design makes everything easy, and yes a great spot there for the Ducati intake tract :twisted: or 2 :wink: downside of the perimiter frame is maybe 2-3kgs heavier than a clever single spar upper. I looked at a ktm 690 yesterday and wondered why they didn't downdraft more even with the perimiter frame, its a cool setup with the frame mounting inside the swingarm between the swingarm and the cases.

it looks more "normal" now with a rear guard and shrouds so no need for a pic :lol:

Outstanding stuff Bushie, congratulations :mrgreen:

Steve

Thanks Steve

more pics small ones this time, bugger me is 800 pixles still too wide ? :evil:

setup for the first whoop test


and after lowering the subframe



also fitted a 53T rear to see if I can get into the stronger 5th and 6th most of the time instead of pissweak 3rd/4th.

New "solid" exhaust rocker pin left, stock right. Two 2mm holes on the middle, a 3.5mm hole from the pin end, as seen in the picture. Oil jets drilled in rocker and the big original oil hole on top of the rocker plugged with a brass plug. The oil line is a brake line and does not flow particularly well, so no risk of starving other oil flows.
Does it make a difference? -Yes, I'm happy but I have no figures. [attachment=0:2nwcp24z]IMGA0925.JPG[/attachment:2nwcp24z]

Would a cush drive hub be nicer to your pissweak 3rd/4th?
A 2T would probably be less pulsatile on the gear box BTW. (I know, its like swearing in church...)

Yes I should run a cush drive hub, most bikes have a Cush in the clutch and for the riding I do they run a cush hub as well, double cushions.. where the husaberg has no cusions.

I'm curious how that Cusion sprocket thing works out

swearing? going to 700 probably increased the pulsations too.. less often but bigger. the er um "husaberg" 300 would be a nice engine to put in a lightweight chassis. they can get them to 92kgs by throwing Ti at them, I reckon 80kgs is possible with Carbon and some natural composite 8O

bushmechanic said:

Yes I should run a cush drive hub, most bikes have a Cush in the clutch and for the riding I do they run a cush hub as well, double cushions.. where the husaberg has no cusions.

I'm curious how that Cusion sprocket thing works out

Click to expand...

I took a 530 "blank" sprocket and cut it down to 520 in the outer "teeth area". Then there was enough material thickness at the bolts, where I drilled out 20mm holes to fit rubber cushes in. Thats not all, but that is the design principle. Thats one way of making a cush drive (worked for me).

Dr_C thats a great Idea, I have some ployurethane car suspension bushes laying about

there are also the aussi/chinga KUSH sprockets but im not sure if they are Bushie proof

Hey bushie, what are your plans for the o8 fuel tank in the background of the shed there. Interested in selling it at all.

Hey Squizz

the tank is just about Rooted its done near 9 000km around my track and worn down to about 0.3mm thick where it rubs on the 3/4" tube of the frame and under the radiator shrouds where I grip it with my knees so Im hanging onto it, could be useful as I might put some kind of engine in the old frame one day too.