geometry alteration question ?

[DIRTY666DOG]

i read raising the back end on vtrs with the use of a 6mm spacer above the rear shock sharpens the turn in which i tried and liked my question is does anyone know by how much the forks would have to dropped through the yokes to achieve the same thing as im a short butt and the 6mm makes that bit of difference to me thanks in advance any of you mathematical buffs ps dropping the forks 6mm doesnt work out the same cheers from the dog

[popkat]

With the 6mm spacer fitted get a long length of flat bar or a peice of door trimming or something similar, lay it along the bike from centre of top yoke/top of tank to the pillion seat then use an angle gauge and note what it reads. Then take out the spacer and drop forks until you get the same angle.

[edds11]

Popkat, I dont think it works that way, its more to do with the geometry of the rear wheel suspension and by using the spacer it basically makes the wheel base shorter

[tony.mon]

It sharpens the steering angle but raises the c.o.g.
It's roughly 3:1, so using a 6mm spacer raises the rear by around 18-20mm, depending on where you measure it.

So a 20mm drop on the front should be enough.

Frankly any more than that tends to make them slap sometimes, but it depends on your weight and riding style, whether you sit forward or further back, take pillions, what tyres you use, and any mods- lighter cans takes weight off the rear and so effectively loads the front proportionally more, so you'll get an increased likelihood of it slapping.
If you don't rag it it'll mostly behave with that setting.

[turbo_billy]

I might be talking complete bo**ocks here, but a ratio of 4:1 sticks in my mind for some reason. ie drop the forks through by 24mm SHOULD equate to 6mm up on the rear. Don`t ask where I got the info because I haven`t got a clue. Try it, if it works, your welcome, if not, sorry........ Just take it steady if you do decide to try

[motostorm]

the storms geometry is fairly ''safe''imo ,you can drop the front a bit without any stability issues , if i were you i would experiment a little , its easy to drop the front and only takes a few minutes , if your shock spring is set standard and your light reduce the shock preload too,,
a friend of mine is very small and light an had put off getting a storm , but i showed him a bike with the preload reduced and the forks dropped (i think ) around 15mm , and it totally changed the bike for him , with no negative issues ,
fyi hes under 5ft and 6okgs at a guess ,
do a little experimenting its important when doing these changes and accessing differences , that your tyre pressures are correct to get good results , there are some bikes get very slappy when you drop the front but i think most would agree theres a bit of scope on the vtr to do this without the bike becoming unstable , hope this helps


id start at 10mm and see if you can feel the difference in how the bike turns

[benny hedges]

I might be talking complete bo**ocks here, but a ratio of 4:1 sticks in my mind for some reason. ie drop the forks through by 24mm SHOULD equate to 6mm up on the rear. Don`t ask where I got the info because I haven`t got a clue. Try it, if it works, your welcome, if not, sorry........ Just take it steady if you do decide to try

i dropped mine by 20mm and its bloody awfull.
very skittish at low speeds and gets tanky slappy when going fast.

if you want to drop the rear you could (like mine) fit a yacugar progressive rear spring to the standard shock and fit the bottom linkage the wrong way round.
the front on mine is -15mm and its nicely balanced.
any more than that its not nice to ride at all - probably even worse with the standard springs in.

[DIRTY666DOG]

thank you all

[Stratman]

I dropped mine by only 5mm and it makes a great improvement

[gl_s_r]

Was that a whole year from the beginning to the end of that thread?

[tony.mon]

Yep, it took him that long to stop shaking after riding it with the forks 30mm through the yokes