frame bracing

Heres an old picture of one of my current projects with an oversized backbone and different style bracing than the normal tube bracing.
The flat angled piece going up down keeps things from moving that way while the offset bent into the edge strengthens it side-side keeping the backbone tubes from moving either way.

Okay, look, I'm not here to argue all day, I've got to get out to the shop.

Take a piece of steel and a piece of aluminum, let's say business cards made of each, and bend them. If the steel is tempered (like a spring), it'll go back to it's original shape, if it's not, it'll stay bent. The aluminum, though, will typically crack in the middle, leaving you two halves.

WAY oversimplified, but that was basically what I was trying to say.

Bracing a frame gives you peace of mind for that ONE TIME you push your scoot past the normal limits you operate in.
For me the rules are
1 More Power equals brace the frame
2 Upgraded tires and suspension equals brace the frame
3 Added weight due to advanced muffin top or adding wieght to bike equals brace the frame
4Pushing the bike alot harder than you used to equals brace the frame

Sorry, But as a retired fire chief I believe in having a safety margin built into as many parts of life as I can . What can it hurt ???????

Biggest reason for me many moons ago was taking the gas tank off my bike and being able to deflect the 3 backbone tubes behind the steering neck with ONE hand. Didnot make me feel warm and fuzzy to race a bike in a straight line or dive into corners with a stock frame that clearly was flexable.
Just My 2 Cents
Dave

Street fighter LTD hit it on the head. Probably isn't necessary as I've seen stock frame KZ running at the dragstrip going in the 7's and over 150 mph without any visible bracing but I would do it if for no other reason then to build it stronger. I like to over-build things for that safety factor also. It doesn't hurt. A couple extra pounds on these bikes is no big deal. Sorta like back-cutting a trans or welding a crank...not necessary for most purposes but good insurance if you can.

Heres an early gpz1100 frame,kawasaki picked up on all bracing the racers had to do on kz bikes they were roadtacing

I agree with StreetFighter KZ's reasons for bracing (advanced muffin-top? :woohoo: ). This frame was designed in very early 1970s and as far as I can tell it never changed till the KZ 1000 came out in 77 and even then the mod was slightly heavier tubing. As Wireman pointed out the GPZs learned from roadracers needs.

One other thing I seem to remember reading was that when the early Z1s were pushed into corners they were OKish but Lord help you if you backed off the throttle even a hair because you then had quite a pucker moment where the frame would flex in a very alarming way.

Reminds me of my early days learning to ride wheelies on an ill handling z1 as a kid! :woohoo:

i had a z900a4 in the 80's that i could throw around all day long with no problem, that had a braces swing arm and mag wheels. then in 2007 i bought a z1a and it used weave about under stress, it preferred the white lines than any direction i was trying for, that bike was all stock. i just took it that the frame was doing that flexy thing,be interesting to find out its all made up and it really was just poor tyres, loose spokes and spongy shocks.

Even with a better swingarm/rebuilt newer rebuilt front end and better brakes z1s will twist like pretzel with serious power put to them! :laugh:

My new build will be off a 74 z1, maybe go big block , but was trying to stray from welding on that frame in hopes one day it will be put back to original condition, 7s 150 mph no frame bracing, nice.

If I was going to try and put a stock z1 frame into the 7s the 1st thing Id do is get really drunk! :woohoo:
If I still wanted to do it after sobering up Id atleast go over every inch and every weld on that frame because they were really scary to say the least from the factory,if I wanted to build a 7 sec turbo /nitrous/bigblock street bike Id probably just go totally off the deep end and do something like this!







:woohoo:

i didnt wanna chop and weld on my frame at first either but it needs it, and i have a 79 ltd which is supposed to have less flex but the frame leaves alot to be desired, head woble at 120 is nasty also so i suspect its not true.