Other Compatible Forks?

[00v_Lucky]

I remember not too long ago a member on this forum switched to a 'busa front end. And this kind of sparked my interest.

So, as the title states I am curious to see which front ends on other bikes are compatible with the 250. More specifically, I would like to switch to inverted forks for cheap. This is because I went to a local bike junk yard with a lot of crashed bikes and some had forks/front ends still in good condition.

So if anyone could let me know the specs or has any knowledge on this subject please help me out!

[DEXSPEED]

i think the guys that can help will be the members from thailand.i am interested to find out too

[Rexbo]

you can fit nearly any other types of forks onto the ninja if you are willing to do a little custom work for the tube that goes through the head. Nearly all the forks have the same design, you'd just need to adapt the head tube that goes into the head bearings to fit your upper and lower triple clamps, and maybe make custom spacers to go on each side of the head tube.

[headshrink]

Interesting idea...

BTW: Can someone explain if there is an actual advantage to the upside-down fork design found on most of the other [more $$] bikes, other than looks????

[Alex]

The two main benefits of USD forks are that they are stiffer in the tripletree to provide better control, and there is less unsprung weight as the smaller lower legs are lighter. Less unsprung weight means the suspension can be tuned better across the board, but helps the most for high-speed damping.

But whether those theoretical advantages become actual benefits on streetbikes, it's certainly up for debate. Some great handling bikes continue to use conventional forks happily, but for all-out sportbikes, it's a hard sell if they don't have the now ubiquitous USD design.

[headshrink]

Thanks for the explaination Alex. I assume we don't have them due to cost?

[bob138]

Originally Posted by headshrink

Thanks for the explaination Alex. I assume we don't have them due to cost?

That's one big reason. Another that I have heard is that it takes a very rigid frame to handle USD forks. The additional stiffness in the forks due to the larger tubes in the clamps means more of the turning force is transmitted to the frame. The ninja's frame is less rigid than a perimeter style frame. Even the ex500's frame is too weak to really handle USD forks when pushed hard so I've heard.

Now whether or not you're average street rider can push the ninja hard enough to tweak a frame is the real question. That I've never heard a definitive answer to.

But as pointed out, the real logic flow chart revolves around cost. Even if you plan on keeping the ninja for a while, how much do you want to sink into the bike? UDS forks require you to get the whole front end. So probably $4-500. New springs and valve emulators, $250ish. Difference in performance, negligible.

Springs and emulators also are lighter than USD's with double rotors most of the time, and less weight = better performance

Bob