Need suspension help for my project
Hey everyone. I'm doing a custom build on my 95 f3 this summer and i was planning on swapping out a 929 front end and a vfr 750 single sided swingarm swap. My question is this, the 929 forks will lower the front of the bike making it more unstable at higher speeds, what can i do to lower the rear end when mounting the swingarm in order to retain the proper handling? i'm not coming up with anything right now and i don't want to have to drop like 400 on a steering dampener. Any help would be awesome. Thanks everyone!
you said since you're using the viffer shock - are you going to be using the traingle system too? instead of your f3 suspension link?
anyways, all you need to do is get a sheet of a 6k series aluminum that's about 1/4 in thick - or maybe a touch thicker (measure your stock ones width first). i think it may be 5/16's - but anyways - it's not all that thick.
then, you essentially place a jack (i've used a bottle jack) underneath your bike's motor or rear part of the frame **closest to the pivot bolt** with your suspension hooked up . everything needs to be in place except the triangles.
raise and lower the bike via the jack to get the geometry you want.
use cardboard to get your 3 holes. this is your template for your triangles that you'll make
drill holes into the aluminum that match the cardboard cut out you just made - try to do both plates at the same time to make sure they're an exact match.
then cut them out into the triangles
and you hook it up and it *should* be the geometry you want. it may vary a bit because you're setting it up when the shock has NO weight on it. so you need to figure out where your shock and dogbone will be with about 600 lbs added to it (assuming 200lb rider and 400lb bike). the springs on the viffer are fairly stiff - so it may only drop 1/2 in or so because of how stiff their springs are. figure out how many lbs/inch their spring goes - and that will give you an idea of how much you need to compensate. (in our example, if you wanted to compensate for your's and the bike's weight (600lbs) and the viffer spring was 1200lb/inch - you'd want to set up the bike to be about 1/2 inch HIGHER than you'd want it to sit with you on the bike)
generally, when you buy aluminum like that - you have to buy in 12inx12in increments - so you could always experiment with a few different sets triangles.
anyways, all you need to do is get a sheet of a 6k series aluminum that's about 1/4 in thick - or maybe a touch thicker (measure your stock ones width first). i think it may be 5/16's - but anyways - it's not all that thick.
then, you essentially place a jack (i've used a bottle jack) underneath your bike's motor or rear part of the frame **closest to the pivot bolt** with your suspension hooked up . everything needs to be in place except the triangles.
raise and lower the bike via the jack to get the geometry you want.
use cardboard to get your 3 holes. this is your template for your triangles that you'll make
drill holes into the aluminum that match the cardboard cut out you just made - try to do both plates at the same time to make sure they're an exact match.
then cut them out into the triangles
and you hook it up and it *should* be the geometry you want. it may vary a bit because you're setting it up when the shock has NO weight on it. so you need to figure out where your shock and dogbone will be with about 600 lbs added to it (assuming 200lb rider and 400lb bike). the springs on the viffer are fairly stiff - so it may only drop 1/2 in or so because of how stiff their springs are. figure out how many lbs/inch their spring goes - and that will give you an idea of how much you need to compensate. (in our example, if you wanted to compensate for your's and the bike's weight (600lbs) and the viffer spring was 1200lb/inch - you'd want to set up the bike to be about 1/2 inch HIGHER than you'd want it to sit with you on the bike)
generally, when you buy aluminum like that - you have to buy in 12inx12in increments - so you could always experiment with a few different sets triangles.
Awesome that helps a lot! thanks. I think i saw a thread of you starting to do the same swap? let me know how all that goes. I'll keep in touch once i start my project. Good luck!
what angle should the shock be at? should it be straight up and down?
what angle should the shock be at? should it be straight up and down?
Last edited by 74demon; Apr 2, 2013 at 10:38 PM. Reason: merged posts
hey man, i just saw you reply on the 929 thread. it came off of a 954 - but they're the same. i sent you an email.
hmmm let me think about the suspension thing (my bad - i thought all the viffers used that triangle set up...) i'll see what i can find for you
hmmm let me think about the suspension thing (my bad - i thought all the viffers used that triangle set up...) i'll see what i can find for you
I have a '93 F2 and did the Gsxr inverted front end fork swap. At higher speeds there is more stability than stock Oem forks. You will enjoy this conversion alot. Make your bike handle like a much newer bike. Enjoy!
Yes, on the triples, front wheel and brakes. I went with the 6 piston GSXR 750 Front brakes.
Slightly shorter by a half inch. I am very happy with the inverted forks. I see no reason to even contemplate buyer a newer bike with this swap.
Slightly shorter by a half inch. I am very happy with the inverted forks. I see no reason to even contemplate buyer a newer bike with this swap.


