TOPIC:

I am trying to decide if I need more bracing on this mount. The stock GPZ bracket is similar but the shock is closer to the frame cross member. I would like to leave it like in the first pic with the addition of some gussets to prevent side to side twisting.



Do I need additional bracing as shown? Would this smaller tubes suffice? Theyare fairly heavy walled. Or would one larger diameter tube to the short cross member be better?


Thanks for any help.
Wayne

Id bring the side/side braces out more toward shock bolt myself

wireman wrote: Id bring the side/side braces out more toward shock bolt myself

Yeppers, they will be. It is just sitting on top in the pic. Do you think I will need more bracing going up?

Hi Wayne, Although I am not an engineer I would say you need the extra brace going up that is seen in the second pic. Looks to me like there might be too much turning (lever) moment exerted on the cross tube by the two flat bars holding the top of the shock. The two triangular braces you have look necessary too. Just my 0.02

If possible, welds should be in compression. You need the majority of the load taken by something inline with the normal movement axis of the shock, in compression with the shock. Those flat bars are okay for limiting for/aft movement, but you need to tie them in vertically like your mocked up tubes. See if you can tie those tubes into an existing joint up near the tank/seat, or add a side/side brace to keep the shock load from spreading the upper frame rails.

my general intuition would tell me you should take that frontward mount and double it to the rearward frame piece that moves diagonally.

kzz1king wrote:

wireman wrote: Id bring the side/side braces out more toward shock bolt myself

Yeppers, they will be. It is just sitting on top in the pic. Do you think I will need more bracing going up?

I think you have the right idea with braces going up,its just a matter of tying them into the flat strap.
I think you have enough surface area with the origional strap pieces on edge that shock is bolted through that the top diagonals probably dont need to come out completely to the bolt hole area but maybe 3/4 of the way.
You might also want to make a short sleeve for inside of each plate the bolt passes through with gap between for shock of course.
This would protect the bracket from the shock bolt egg shaping holes over time as suspension works over bumps in road,it would give more support to the bolt also to keep it from bending also.

So from Wires suggestion to bring the sides out more and Haybus and bluezbike's recommendation of more bracing I came up with this. I think it is going to work! Thanks guys.

You should have boxed in your original plates with a piece on top to make an upturned "C" and took just one larger ( 20 to 25mm ) diameter tube from the top of that to the middle of that small cross tube to line up with the backbone so the suspension forces are transfered to the headstock.
Those tubes being welded at the side of the plates are in sheer and not really the best set-up.
The little side fillets are ok to resist sideways movement but would have been better if formed as large triangles with more of a footprint on your additional cross tube.

Would it help if the small tubes were tied together with some flat in the middle? They are welded right at the sides of the shock. I had thought of capping the top of the mount and using a larger tube but only head heavy wall stuff handy.

Here is the bracket ma kaw used.


Are any of your concerns saftey related or handling concerns. Thanks
Wayne

is that a trailer hitch?

Zed 1014 sounds right, those side gussets arent tied really to anything, compression works against them.

Tie the side of that piece together plug the backbone and tie up to a plate directly on the backbone

My .02