Pre gen to new gen forks and swing arm swap floating feeling problem

[Major1997]

Ok so I own a Kawasaki gpx 250r II 1988 and I have swapped the front triple tree down including the wheel and brakes and rear swingarm back including wheel, brake and suspension components, of a ninja 250 2009 and I took it out for its maiden voyage and the bike seems to feel like it's not settled on the road kinda floaty feeling, Kinda like a flat tyre and the front end was really easy to turn witch made it turn by itself when leaning.

I thought the triple tree castle nut thing wasn't tight enough so I tightened it but it cant torque it since I don't have the so would love to know if that is important but even tighter it still felt wrong.

I checked all the bolts torques and made sure the tire pressure was good and nothing moves when I shake it while it's in the air so I'm stumped at what it could be.

The rear tyre is flat-spotted but I can't imagine it would be the problem.

I would love anyone ideas on what could be the problem or if I was meant to add a washer somewhere or something while doing this swap, any info or ideas would be greatly appreciated.

[Triple Jim]

Originally Posted by Major1997

...and the front end was really easy to turn witch made it turn by itself when leaning.

Do you mean it was "falling into" turns? Like you start a turn and it seems like it's going to fall over that way?

Or do you mean it was like a chopper with an extended front end, that when you lean into a turn it tries to turn the handlebar farther and you have to countersteer to keep it on the line you want?

Welcome to the board, Simon!

[Major1997]

Originally Posted by Triple Jim

Do you mean it was "falling into" turns? Like you start a turn and it seems like it's going to fall over that way?

Or do you mean it was like a chopper with an extended front end, that when you lean into a turn it tries to turn the handlebar farther and you have to countersteer to keep it on the line you want?

Welcome to the board, Simon!

Like a chopper sounds about right.

[Triple Jim]

That's often because of the fork tubes being too long. I don't know what bars you're using... can you try lowring the triple clamps on the fork tubes (extending the tubes up through the clamps) a little at a time?

[Major1997]

Originally Posted by Triple Jim

That's often because of the fork tubes being too long. I don't know what bars you're using... can you try lowring the triple clamps on the fork tubes (extending the tubes up through the clamps) a little at a time?

okay, I will try, I was running the same bars on the pre-gen forks and it didn't do it, so thought it was really weird. thank you though

[Major1997]

Originally Posted by Triple Jim

That's often because of the fork tubes being too long. I don't know what bars you're using... can you try lowring the triple clamps on the fork tubes (extending the tubes up through the clamps) a little at a time?

okay, I have seemed to have fixed it, it looks like I tightened the triple tree castle nut way too tight and lowering the suspension also helped with the leaning auto steer problem.

[Triple Jim]

Originally Posted by Major1997

okay, I have seemed to have fixed it, it looks like I tightened the triple tree castle nut way too tight and lowering the suspension also helped with the leaning auto steer problem.

Are you saying that the steering bearings were overtightened so they were not turning freely?

[DannoXYZ]

yup, bearing preload too tight would interfere with trail's self-straightening action. It would require more off-centre aim to generate enough corrective force to move steering. Then it would overshoot centre until enough force was generated to swing back. Thus that wandering feeling. With smooth bearings, self-centering occurs much easier and bike tracks straight.

[Major1997]

Originally Posted by Triple Jim

Are you saying that the steering bearings were overtightened so they were not turning freely?

yea, I was stupid I didn't realise they barely needed tightening, I'm probably gonna get a socket or something to make sure it's at the required torque but it seems good, the only thing I've noticed so far now is how hard the suspension is it's extremely aggressive. I don't know if it's normal but now it's way harder than my 2016 CBR 500

[Triple Jim]

Originally Posted by Major1997

yea, I was stupid I didn't realise they barely needed tightening, I'm probably gonna get a socket or something to make sure it's at the required torque but it seems good, the only thing I've noticed so far now is how hard the suspension is it's extremely aggressive. I don't know if it's normal but now it's way harder than my 2016 CBR 500

It's the nut with the notches under the top triple clamp that takes a spanner to turn, that makes the adjustment. Then the bolt on top is tightened to lock the adjustment. You can turn that bolt tight without a problem if the adjustment is not too tight. It should be adjusted to just take out all the play, but not so much that you can feel any friction when turning. This all has to be done with the front wheel off the ground so you can feel what's going on.

[DannoXYZ]

Originally Posted by Major1997

yea, I was stupid I didn't realise they barely needed tightening, I'm probably gonna get a socket or something to make sure it's at the required torque but it seems good, the only thing I've noticed so far now is how hard the suspension is it's extremely aggressive. I don't know if it's normal but now it's way harder than my 2016 CBR 500

did you grease all the needle bearings in pivots on rear suspension?