Almost tank slapper

agentbad · September 6th, 2013, 04:37 AM

So I was riding to work this morning and for fun I let of go of the bars just to see if I could balance for a second. Well they started shaking back and forth getting close to a tank slapper and I grabbed them immediately and everything evened out. Now I wasn't going to fast so I just wanted to make sure nothing was wrong with my front suspension to cause that. I have noticed a rubbing sound occasionally from the front but I was thinking it may be a warped rotor.

csmith12 · September 6th, 2013, 04:50 AM

A warped rotor will not be so "occasional" so be sure to check for a sticking front caliper as well.

Asspire · September 6th, 2013, 05:02 AM

check for play in head bearing, check tire pressures, check wheel bearings

check local dealers for a trade in for a R6, they come with steering dampners

agentbad · September 6th, 2013, 05:05 AM

Okay ill give the caliper a look as well. Would low brake fluid cause it to stick as well? I can't imagine a caliper being bad after only about 7000 miles on the bike though the last owner took bad care of it.

I would love an R6 but I don't have the monies right now. The FZ6 or maybe a ninja 650 will be my next progression before I consider supersports.

csmith12 · September 6th, 2013, 05:12 AM

It's unlikely that low brake fluid would cause such an effect. If the caliper is sticking/dragging, a good cleaning (may require dissasembly) may solve that problem.

Asspyre added some good items to check also but didn't mention the stem nut. I had to tighten mine just last week. You can check for a loose stem nut/play in bearings by pushing the front forks up and down. Listen for a pop/clunk sound.

Alex · September 6th, 2013, 05:50 AM

http://www.ninjette.org/wiki/Front_End_Wobbles

agentbad · September 6th, 2013, 06:05 AM

Quote:

Originally Posted by Alex

http://www.ninjette.org/wiki/Front_End_Wobbles

Well that's a bit of a relief. Thank you for that. I'll still give things a once over just to be sure.

jkv45 · September 6th, 2013, 06:34 AM

I would check the alignment of the rear wheel with something more accurate than just the hash marks on the swingarm - like carefully measuring from the center of the axle to the center of the swingarm pivot.

You shouldn't need a steering damper or anything additional to give you decent stability.

As noted, also check tire pressure, and look closely for unusual wear patterns on the front tire.

Motofool · September 6th, 2013, 07:01 AM

Quote:

Originally Posted by agentbad

..........I'll still give things a once over just to be sure.

Bob,

Besides checking all the things pointed above, check if your front tire has weights on any side.
If it does, move them to the opposite lip and try again.

I assume that your handlebar has weights at both ends.
If they are not there, you need to add some.

Also, read this thread:
http://www.ninjette.org/forums/showthread.php?t=121404

csmith12 · September 6th, 2013, 07:02 AM

lol Hernan!

How could I forget to ensure the tire(s) was in balance. Duh!

CC Cowboy · September 6th, 2013, 07:20 AM

Check your tire wear for scalloping.

alex.s · September 6th, 2013, 08:43 AM

so as the front tire wears down, its no longer in balance the same as it was when it was fresh and balanced... so now its out of balance because there is less rubber.

or something

GeorgeRYoung · September 6th, 2013, 08:48 AM

Did some digging for the Concours, results here:
http://web.ncf.ca/ag136/frontWheelWobble.htm

The solutions are:
1) tighten steering head bearings
2) steering damper
3) put up with it

agentbad · September 6th, 2013, 09:06 AM

Quote:

Originally Posted by CC Cowboy

Check your tire wear for scalloping.

That sounds delicious I mean OK I will check that out. Are the head nuts the big ones on the top of the bars? I haven't noticed any unusual wear and as long I keep one or both hands on the bars I have no issues. My tires are the crappy OEM dunlops.

Motofool · September 6th, 2013, 09:14 AM

Sorry, I forgot to mention the ball bearings of both wheels and the needle bearings of the swing-arm: they should not have any noticeable play.

A chain with tight links could be introducing some cyclic disturbance as well.

The possible dynamic imbalance of the front tire is the most critical in this case, because weights or heavy spots out of center induce small left-right-left steering inputs for each revolution of the tire.
Those little inputs are dampened by the hands, but in hand-free mode, they could get amplified into resonance at certain speeds.

CC Cowboy · September 6th, 2013, 09:45 AM

Quote:

Originally Posted by agentbad

That sounds delicious I mean OK I will check that out. Are the head nuts the big ones on the top of the bars? I haven't noticed any unusual wear and as long I keep one or both hands on the bars I have no issues. My tires are the crappy OEM dunlops.

Yes Alex and all his comrades fit into this category.

agentbad · September 6th, 2013, 04:58 PM

Handlebars do have weights but didn't see any weights on the front tire.

Quote:

Originally Posted by csmith12

A warped rotor will not be so "occasional" so be sure to check for a sticking front caliper as well.

Also checked the brakes while I was down there to try and get to the source of the occasional noise. It seems like the pistons are getting stuck so I guess I need to take a toothbrush and brake cleaner to them. Also the pads may need changing.....

FvnnyL3tt3r1ng · September 6th, 2013, 06:09 PM

Pads still look like they have life left to me.

csmith12 · September 6th, 2013, 06:23 PM

Agree, looks like you can squeeze a few more miles out of the pads but I can understand replacing while you have them apart. Crossing my fingers that cures your issues.

September 6th, 2013, 04:37 AM	#1
agentbad ninjette.org sage Name: bob Location: Earf Join Date: Apr 2013 Motorcycle(s): 2005 Ninja 250, 2006 SV650N Posts: 642	Almost tank slapper So I was riding to work this morning and for fun I let of go of the bars just to see if I could balance for a second. Well they started shaking back and forth getting close to a tank slapper and I grabbed them immediately and everything evened out. Now I wasn't going to fast so I just wanted to make sure nothing was wrong with my front suspension to cause that. I have noticed a rubbing sound occasionally from the front but I was thinking it may be a warped rotor. Last futzed with by agentbad; September 6th, 2013 at 06:08 AM.

September 6th, 2013, 04:50 AM	#2
csmith12 The Corner Whisperer Name: Chris (aka Reactor) Location: Northern KY Join Date: May 2011 Motorcycle(s): 2010 250 (track), 1992 250, 2006 R6 (street/track), 2008 R6 (track) Posts: Too much. MOTY 2015, MOTM - Nov '12, Nov '13	A warped rotor will not be so "occasional" so be sure to check for a sticking front caliper as well. __________________________________________________ Goal: Shake A Million Hands \| Look through the corners \| Track Day Prep \| Closest track? \| The Mid-Ohio School

September 6th, 2013, 05:12 AM	#5
csmith12 The Corner Whisperer Name: Chris (aka Reactor) Location: Northern KY Join Date: May 2011 Motorcycle(s): 2010 250 (track), 1992 250, 2006 R6 (street/track), 2008 R6 (track) Posts: Too much. MOTY 2015, MOTM - Nov '12, Nov '13	It's unlikely that low brake fluid would cause such an effect. If the caliper is sticking/dragging, a good cleaning (may require dissasembly) may solve that problem. Asspyre added some good items to check also but didn't mention the stem nut. I had to tighten mine just last week. You can check for a loose stem nut/play in bearings by pushing the front forks up and down. Listen for a pop/clunk sound. __________________________________________________ Goal: Shake A Million Hands \| Look through the corners \| Track Day Prep \| Closest track? \| The Mid-Ohio School

September 6th, 2013, 05:50 AM	#6
Alex ninjette.org dude Name: 1 guess :-) Location: SF Bay Area Join Date: Jun 2008 Motorcycle(s): '13 Ninja 300 (white, the fastest color!), '13 R1200RT, '14 CRF250L, '12 TT-R125LE Posts: Too much. Blog Entries: 7	http://www.ninjette.org/wiki/Front_End_Wobbles __________________________________________________ Montgomery Street Motorcycle Club / cal24.com / crf250l.org / ninjette.org ninjette.org Terms of Service Shopping for motorcycle parts or equipment? Come here first. The friendliest Ninja 250R/300/400 forum on the internet! (especially Unregistered)
	1 out of 1 members found this post helpful.

September 6th, 2013, 07:02 AM	#10
csmith12 The Corner Whisperer Name: Chris (aka Reactor) Location: Northern KY Join Date: May 2011 Motorcycle(s): 2010 250 (track), 1992 250, 2006 R6 (street/track), 2008 R6 (track) Posts: Too much. MOTY 2015, MOTM - Nov '12, Nov '13	lol Hernan! How could I forget to ensure the tire(s) was in balance. Duh! __________________________________________________ Goal: Shake A Million Hands \| Look through the corners \| Track Day Prep \| Closest track? \| The Mid-Ohio School

September 6th, 2013, 05:02 AM	#3
Asspire Fix It Till Ya Break It Name: Asspyre Location: T.Dot Join Date: Oct 2011 Motorcycle(s): 08 250RRrrrr Posts: 623	check for play in head bearing, check tire pressures, check wheel bearings check local dealers for a trade in for a R6, they come with steering dampners

September 6th, 2013, 05:05 AM	#4
agentbad ninjette.org sage Name: bob Location: Earf Join Date: Apr 2013 Motorcycle(s): 2005 Ninja 250, 2006 SV650N Posts: 642	Okay ill give the caliper a look as well. Would low brake fluid cause it to stick as well? I can't imagine a caliper being bad after only about 7000 miles on the bike though the last owner took bad care of it. I would love an R6 but I don't have the monies right now. The FZ6 or maybe a ninja 650 will be my next progression before I consider supersports.

September 6th, 2013, 06:34 AM	#8
jkv45 Rev Limiter Name: Jay Location: WI Join Date: Jul 2013 Motorcycle(s): '06 SV650n, '00 Derbi GPR, '64 CA77 Dream 305, '70 CL450 Scrambler, numerous dirt bikes Posts: A lot. MOTM - Jun '18, Oct '16	I would check the alignment of the rear wheel with something more accurate than just the hash marks on the swingarm - like carefully measuring from the center of the axle to the center of the swingarm pivot. You shouldn't need a steering damper or anything additional to give you decent stability. As noted, also check tire pressure, and look closely for unusual wear patterns on the front tire.

September 6th, 2013, 07:20 AM	#11
CC Cowboy ninjette.org certified postwhore Name: Whodat Location: Ware Is.,MA Join Date: Jan 2009 Motorcycle(s): I pass the wind! Posts: A lot. MOTM - Mar '13, Jun '14	Check your tire wear for scalloping. __________________________________________________ If everything seems under control; you're just not going fast enough!
	1 out of 1 members found this post helpful.

September 6th, 2013, 08:43 AM	#12
alex.s wat Name: wat Location: tustin/long beach Join Date: Sep 2009 Motorcycle(s): wat Posts: Too much. Blog Entries: 5 MOTM - Oct '12, Feb '14	so as the front tire wears down, its no longer in balance the same as it was when it was fresh and balanced... so now its out of balance because there is less rubber. or something __________________________________________________

September 6th, 2013, 08:48 AM	#13
GeorgeRYoung ninjette.org member Name: George Location: Ottawa, Canada Join Date: Jun 2011 Motorcycle(s): EX250, C10 Concours Posts: 109	all bikes have a resonance around 45 mph Did some digging for the Concours, results here: http://web.ncf.ca/ag136/frontWheelWobble.htm The solutions are: 1) tighten steering head bearings 2) steering damper 3) put up with it

September 6th, 2013, 09:14 AM	#15
Motofool Daily Ninjette rider Name: Hernan Location: Florida Join Date: Mar 2011 Motorcycle(s): 2007 Ninja 250 Posts: A lot. MOTY - 2016, MOTM - Dec '12, Jan '14, Jan '15, May '16	Sorry, I forgot to mention the ball bearings of both wheels and the needle bearings of the swing-arm: they should not have any noticeable play. A chain with tight links could be introducing some cyclic disturbance as well. The possible dynamic imbalance of the front tire is the most critical in this case, because weights or heavy spots out of center induce small left-right-left steering inputs for each revolution of the tire. Those little inputs are dampened by the hands, but in hand-free mode, they could get amplified into resonance at certain speeds. __________________________________________________ *Motofool* *.................................Never ride faster than your guardian angel can fly* "Mankind is composed of two sorts of men — those who love and create, and those who hate and destroy. Love is the bond between men, the way to teach and the center of the world." - José Martí
	1 out of 1 members found this post helpful.

September 6th, 2013, 06:09 PM	#18
FvnnyL3tt3r1ng ninjette.org certified postwhore Name: Justin Location: Florida Join Date: Aug 2012 Motorcycle(s): Ninja 250 2001 Posts: A lot.	Pads still look like they have life left to me. __________________________________________________ Mods: Offset clutch pressure plate

September 6th, 2013, 06:23 PM	#19
csmith12 The Corner Whisperer Name: Chris (aka Reactor) Location: Northern KY Join Date: May 2011 Motorcycle(s): 2010 250 (track), 1992 250, 2006 R6 (street/track), 2008 R6 (track) Posts: Too much. MOTY 2015, MOTM - Nov '12, Nov '13	Agree, looks like you can squeeze a few more miles out of the pads but I can understand replacing while you have them apart. Crossing my fingers that cures your issues. __________________________________________________ Goal: Shake A Million Hands \| Look through the corners \| Track Day Prep \| Closest track? \| The Mid-Ohio School

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