Not long ago I bought a second zzr1400(uk) I have an 06 and now an 07 aswell.When I bought it ,it had quite alot of panel damage and a few other bits, Ive been stringing her up to check wheel alignment. I know something is bent but still trying to figure it out,Its had a knock on the front of the right hand side of the top yolk, Wonder if you guys have any ideas on this ,its easy to go and replace everything but I want to know what it is. Is there any particular bits that are prone to bending.
With the front wheel straight ahead (measured,including rear wheel) Both wheels are vertical. Both top and bottom yolk seem to be aligned I shall try and measure relationship to each other tomorrow but both are turning to the right slightly compared to the front wheel. Having removed both fork top caps I have checked both tubes run fully and cleanly up and down the full length, and they do.They also both rotate fully inside the yolks easily. Do they bend ?
.......Im fairly certain the frame is not bent, its just something on the front end. Has anyone come across a common problem?
Thanks again in anticipation
Andy Grin

Maybe........the top yolk just needs to be loosened and then reset again?Could be tweaked in the top,or lower triple clamp?(maybe BOTH?)Loosening both and resetting may be your answer?Maybe one fork is higher than the other somehow?Any visible damage to the fork tubes or bottom fork where the calipers are mounted?Seems like she'd have to take a pretty good hit with visible damage to bend the chassis?I'd think the frame would crack first,rather than bend somehow.Maybe at the steering stem housing there?Any damage?Scraped paint?REPAINTED spots?How about the front wheel-any sign of damage to the rim(maybe she smacked a curb?)How bad of a "knock"did she get?Dents or cracking?Doesn't sound like the fork tubes are binding.Sounds like they got twisted some.When you pump the forks-any noises?Any feeling of friction through the lever?They could be bent "slightly" and you might not see it-just enough to throw her off a tad.And the fork action might still seem fine if the bend wasn't "noticeable".Hope ya get er fixed!Ride safe there in the UK!!(there's lots of parts out there-a set of forks would be easy to find-probably not too expensive either).I'd be careful ridin a big bike like this with an "unknown" front end issue.Cheers!

* Last updated by: blue07 on 8/24/2009 @ 4:38 PM *

To me, the proverbial, "drop a swiss watch" and now how can you tell time? Like, fork axle times the pressure it took to bend forks and upper/lower crowns?

Axle: First you remove the whole front end off the frame. Then you assemble the front end on the bench. You have a set of V-blocks so you can roll the axle running true. True that? No, then buy new.

Upper Crown: Then you lay the upper crown on a surface plate and rock it back and forth to see how bent the pinchers tweaked one way. The other part of the crown moved the other way. Just run your finger across the slit or the pinch halves and one side will not run true to the other side. Hammer out my pinch wave? Nose way, you know I am buying new.

Forks: Here is where you disassemble and measure the same run-out as you did with the bent axle. You could bend the forks back, but they, "S" back in shape. Take a metal coat hanger, bend it past 90°. Now straighten it out. See how you have that chicane or the S wave? Fork that! Buy new.

Lower Crown: Now, with all the parts above on the bench, we will assemble the front end all in the static. So, I am on the axle to both lower forks and those are bolted with wheel and spacers in place. I slide the lower fork down and pinch the lower crowns down. I now lay my upper crown over the forks and see how they lined up. If I lower my upper crown on the forks, to see how much the forks are bent with the lower crown; if I have to force the upper crown to work and not have it fit right down, then the lower crown is bent. The upper crown's center hole and the center stem of the lower crown, do not line up perfect either, but the stem is bent to one side just slightly. I'd be buying a lower crown.

Races: I want the impact of the front end to show me ball indents so bad, it would be a waste not to rebuild the front end complete, knowing the lower crown does not come with any race. I am buying a race set to freshen up the indents to the old races so I do not notch the steering down the road it's hard to keep it straight down the road.

Frame: I am with a magnifying glass, finding weld separation at the neck area. and all about 6 inches back for any other welds that look like they took a hit and bent to one direction, the sheer at the welds would pick that up. I'd buy, not re-bend a frame.

Well thats something to be going on with, no damage to rim very very light scrape on bottom of lower right leg( on the bronzy bit)and as I said before light graze actually on the handle bar mount on top of the right fork leg.
I thought there maybe a common area that getss bent,,,,Ill strip it all down and check it all properly.I want it to handle properly and of course be safe so no short cuts .ill let you know what the problem is when I find it.
Thanks guys for your input and I even understand Hubs post this time ,you are slipping!
Andy Grin

Ok guys I have stripped all the front end down and low and behold things become much clearer.
The top yoke was removed and when offered up again did not line up quite right with the fork tops , and the clamping bolts were slightly off line with how they should be.
Axle checked ....perfect
Fork legs checked....amazingly accuratley made left was within 0.2mm and right 0.31mm over the overall length,checked over both planes so am happy with those.
Lower yoke can be seen to be twisted backwards on the right hand side which ties up with the scrape on the right top yoke, checked on flat plate ,confirmed bent....Will it straighten,,,,,FORK that, I am buying new.(HUB)
Just to confirm the frame is ok i shall crack test around the headstock with some kit I have from work in the morning and then its off to the dealers to order top and bottom yoke!

Regards Grinner