Hi all,
I've started to notice something that i hadn't when i recently purchased the bike and that's at low speed it seems the front end is fairly bouncy and busy. I'm not sure if its been there all along and i just hadn't noticed it or not. The best description is that at speeds below 40 and rpm under 4k and whether coasting or accelerating lightly i notice that the front end has alot of vibration on what appears to be smooth surface roads. I have played around with the front fork clickable setting and this hasn't made any noticeable difference. I also was speculating that it may have something to do with the risers i recently installed.. went from 3/4" to 1.25" and then lastly stacked them both at 2". So i removed the stack and went back to 1.25" and it seems slightly better, but not 100% smooth as i would expect. Under normal to hard acceleration and anything over 4k or so and i don't notice this issues and perhaps that is due to the engine vibration increasing thru the bars at higher rpms.
Wondering if anyone else has run across this and whether or not it seems normal.
I have 42/42 psi in the tires
Front fork settings: 5 lines / rebound damping - 7 out / compression damping - 10 out
Rear: magazine suspension settings
Also, i checked the front tire for any possible screw/nail/debris and its clean and also only has 800 miles on it.
Thanks for the help

Sounds like a worn front tire. Can you see any cupping of the front tire? Look at the rain cuts in the tire. One side looks higher than the other. How old is the front tire? Did you change just the rear and kept the front?

Actually the front and rear are new and purchased by the previous owner in Nov 2019 at 3k miles.. I bought the bike in late March at 3350 miles so it's not worn.. But I suspect possibly the bike did alot of sitting as evident in the mileage so perhaps a flat spot or balancing needed, not sure.
I just updated the rebound damping from 7 clicks out to 4 clicks out to match magazine recommended and will see if this makes any difference on next ride..
If not I may have to jack the front wheel off the ground and give it a spin to see if anything is apparent

No, not the risers. For example, if you let go of the bars the vibe would still be there is my way of looking at it.

Front wheel off ground. See if it hangs up or spins. Stab the front brake and release, see if the wheel hangs up. Sight down the front of the disc(s) and see if it runs true on the spin.

Go to the front tire and look for that rain groove step. PO might have put miles on the tires, but say the tires were not at that pressure all the time.

Centrifugal force, the constant heat, doubt the flat spot would do it... however, wipe the tire down, rub your hand over the whole tire and find that divot if it was significant to keep the flat spot from rolling out.

Load or lift you can still feel it roll, so I'm more attainment you chase that step in the tire grooves.

.Ya covered everything...except...balancing!

'busy or bouncy'..is it wiggling just barely?Is that what you mean?As the tire wears,it loses material originally balanced for a new tire.The smoothness can degrade over time.It doesn't need to look 'bad'.Necessarily.

Like Hub said...not the risers.Factor that out.This vibration.More intense at braking?Pulse in the brake lever?

'perhaps that is due to the engine vibration increasing thru the bars at higher rpms'....there shouldn't be any increase in engine vibration at all.I can't even feel the motor running on mine.Virtually nothing.If vibration is 'increasing' going faster.I'd say balance the wheel first.It shouldn't be vibrating at all.This guy didn't add some sort of 'auto balancing' stuff in that tire did he?
While yer at it,do the rear as well.

* Last updated by: Grn14 on 5/28/2020 @ 1:15 AM *

I think you might as well try balancing but I never had an issue with it and my weights have flown off. No change.

I would have said "tire cupping" as Hub said. Even though that seems pretty unlikely with only 300 miles on the tire I have a feeling that might be it.

I'd check the rotors as Hub mentioned after a good ride. They're bound to rub the pads in one spot after the bike has sat a while. Same thing with stabbing the brake with the wheel up. The pads will drag lightly after that and that's normal. You could always do a runout test with a dial gauge. That will tell you if the rotor's warped.

Thanks guys for the advice.. yea i guess the riser remover was just a placebo effect. I re-installed the 2" risers this morning. And to answer a question posted, the sensation is not a wiggle but more that the front end is overly sensitive and im feeling every bump in the road when i don't even see any.
I'm going to try to get the front wheel off the ground today and see if i can notice anything not right.

If nothing reveals itself, try backing off a couple of clicks on your compression damping.

Another suspicion in case it may be relevant is that im assuming the fork oil has never been changed and its a 2014 model, so 6 years and 3800 miles.. wonder if that could be a contributing factor.. i do see some debris rings (3 visible rings) on the forks but not any leaking oil

I have 42/42 psi in the tires

At 42psi I'm surprised you're not bouncing right off the road.

Drop psi down to 34-36 psi.

42psi is to high unless you weight like 300lb and
bring your 300lb wife along too. Then 42psi probably good.

piken is correct owner's manual wise. But here is the observation...(s) I have experienced with just a few feet of movement down the driveway. I back down the drive in gear, clutch pulled, I can feel the drag of new oil being half 50w and half 10w.
When I begin to move the bars on the way down, I can feel the front tire act like a pancake, rather than my ice skate blade feel with 42p is the V pressure I'm looking for, not a low U kind of pancake pressure flattened out more.

What bumps?

Now it sounds like your frontend settings are too tight.I'm running 41 psi front,40 rear.It's smooth as can be.The frontend while holding the brake lever should dive and return in about a one second time.With no topping out then settling.Bike not moving.That would be your preload setting.Close the compression,then reset to the factory suggestion for 'softer'.

* Last updated by: Grn14 on 5/28/2020 @ 9:29 AM *

That's interesting about the tire pressure.. i thought it was 42/42 as listed in the manual. I weigh 175lbs and will try the suggested drop in air pressure for the front tire and see how that behaves on my next ride.
Btw.. found this link which was jam packed with great feedback on air pressure that you guys discussed in the past:
http://zx14ninjaforum.com/messages.cfm?threadid=03FBB642-A8A0-A7DA-54462687E892D4F9
ill try 38/40 on my next ride and see how she feels with that.. i rarely take a passenger

In testing the forks and rebound, while off, i press down and then bounce right back and stop right away, so that seems to be good

Yes.It should come back up in a second.Not fly right back up.
You can google 'dave moss garage'.He's suspension tuning a 14r at some raceway.Very good video(s).

* Last updated by: Grn14 on 5/28/2020 @ 10:34 AM *

i thought it was 42/42 as listed in the manual. I weigh 175lbs

42/42 is what it says on any DOT tire I have used. I'm about 215-225 and I use 42/42 if I'm not sport riding. It is bumpier than lower pressure but the steering feels more precise and you can tell it rolls easier when pushing the bike. The tires probably stay cooler and wear less too.

42/42 is what it says on any DOT tire

Not really what it says.

It's the required DOT Safety Max load rating label for the tire and says....

"Max Load 805lbs at 42psi Cold"

This is showing you the max load the tire can take.
Any heavier of a load and you wouldn't be able to add
psi over recommended 42psi max causing the tire to flex to much and over heat.

Has "nothing" to do with recommended tire pressure.

Correct tire pressure depends on load and psi to get the
correct amount of heat in the tire.

To low psi with to high a load over heats tire.

To high psi with to light of a load tire doesn't
get warm enough for best traction.

Both can cause a unsafe condition.

The proper way to adjust psi is the conditions you are
using the tires.

You should measure the tire cold and then measure again
after the tires are warmed up.

This is the "only" way to adjust the psi properly.

For street I look for a 3-4 psi difference between cold and hot

For track I look for a 5-6 psi difference unless using warmers.

These numbers can change depending on load, temps, tires, usage, moisture content
from compressor air (humidity). Also the reason some use Nitrogen to fill their
tires to eliminate moisture content creating a more consistence cold to hot variance
between tire changes.

Bring a gauge with you and check psi. Only need to do a couple
of times to get you in the right range to set your tires.

Riding 2 up, check again and make a note.

I rode today on 38/40 and it does seem a bit better, again not 100% but its definitely more tolerable now and not as big an issue. I'll prob live with it until its time for a new tire up front

What brand of tire? I put a Angel GT on the front of my bike and absolutely hated it. Felt every pebble, often got bounced off line. I guess the carcass on that tire is very stiff. I now have Conti Sport Attack and love them. They have a really soft carcass, and absorb bumps really well. To the point that some roads I used to avoid are now on the menu for fun times. I'm sure the Attacks won't grip as well on the track.

Mad

Gotta go with those Conti Attack tires.Very nice.I keep mine at 40,40 psi.

* Last updated by: Grn14 on 5/29/2020 @ 11:39 AM *

Thats the same tires on my bike - Continental Sport Attack

I put a Angel GT on the front of my bike and absolutely hated it. Felt every pebble, often got bounced off line.

As a follow-up, i was able to lift the front end off the ground using my floor jack and a 1x4 under the exhaust headers and i spun the wheel looking for nails/screws, high/low spots or side to side variance but did not notice anything unusual. I'm going to see about bringing it in to a service shop to have the front balance checked. I may ask them to check the rear as well as i noticed it did not have a weight attached to the wheel while the front does.

A fork lift stand would be the easiest and safest way to lift the front to spin the wheel. The stock headers are pretty strong though. I avoid lifting under the oil pan too even though the front is lighter than the rear.

so you raised the front while on the sidestand then?I know it would work,but pretty risky eh?I bought a heindle pivot stand.Very secure and easy to use.Only really use it on my H2,but I used it on my 14r once I think.

* Last updated by: Grn14 on 5/31/2020 @ 11:45 PM *