Author Topic: Downtown 300i front end wobble  (Read 6524 times)

windwheeler

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Re: Downtown 300i front end wobble
« Reply #15 on: March 24, 2015, 02:14:31 AM »
It amazes me how tire threads and "oil threads" are similar:  Never ending personal "opinions".
 
I agree that the Michelin tires are "quite good" (but, NOT perfect at all either), and I disagree that the Kenda tires are that bad to have to be taken off after 400 miles. That's "personal preference", not more.

I went with all my motorcycles and scooters through about 200 tires so far, 65% of that are rear tires, 35% front. 
I had only two tires that I absolutely hated, or, did a very lousey performance (wear), and I am not naming the brands, because it was apparently a "screwed up model", or production run of a tire they produced. Actually one manufacturer gave me a FREE new "other tire", (different model) and it was fine. 

So, do not be totally discouraged by lower price in regards to grip, however "usually" the more expensive tires do have less issues with "wobble" as they are more precisely manufactured (not only top to bottom = "static balance", but also side-to-side evenness = dynamic balance = related to handlebar shake, exactly what we are discussing here.  Right?!

So, leaving all personal "Opinions" behind, IF your local scooter/motorcycle shop has an electronic balancer where they see the "dynamic values" and also can correct them, then you should work with them all the way through rather than buying "cheap" some grey market second/third quality tire on-line....  You (can quite often) get what you payed for, good or bad... either way.
« Last Edit: March 24, 2015, 12:01:40 PM by windwheeler »

mrbios

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Re: Downtown 300i front end wobble
« Reply #16 on: March 24, 2015, 06:34:30 AM »
It amazes me how tire threads and "oil threads" are similar:  Never ending personal "opinions".
 ...

I had no problem with the original OEM Kenda tires except the common cracking in the side wall after 6 years and 2600 miles.  I rode with the cracks and ran the tires up to 8000 miles then replaced them.  Even though I bought my last and new set of tires online they are quality brands - Avon & Michelin.  Regarding the shaking handle bars - it's not the balance or tires as both the Kenda and Avons did / do the exact same thing at the same speeds regardless of miles.  The Avons were installed and balance by my local dealer at a cost of $98 just to mount / dismount and spin balance.  I removed and reinstalled the tires from the scooter myself.  Most local shops in SD don't give any discount for buying the tires from them and don't stock my rear tire size.  Over the years I've seen increasing shoddy work by dealers and bizarre polices - for my BMW we can't install the tires you just bought from us because we don't sell bmw.  Why didn't anyone tell me that before I bought the tires? AND you sold and installed the tires that I'm currently replacing!  They recanted and agreed to install them.  When I install these Michelin's I might just get the front balanced.
PaulC

windwheeler

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Re: Downtown 300i front end wobble
« Reply #17 on: March 24, 2015, 11:57:17 AM »
I for my BMW we can't install the tires you just bought from us because we don't sell bmw.  Why didn't anyone tell me that before I bought the tires? AND you sold and installed the tires that I'm currently replacing!  They recanted and agreed to install them.  When I install these Michelin's I might just get the front balanced.

Mrbios, this seems to be quite a lousy dealer how he treated you, but we have good and bad ones in the country, so, it is fortunately not the standard.  Most good dealers would not do that to a customer what you experienced.

I understand wheels and tires very well due to my business background.  There are unfortunately only very few shops (motorcycle) that do understand how to counter "steering wobble" on the electronic balancer. A static balancer can not do this, it can ONLY give a regular balance, which does not address the wobble problem. The wobble has often to do with the tire construction itself and then the final dynamic balance, if you want to do the best to remove a handle bar wobble. Some can not be resolved, and for example Kawasaki installed steering dampers to resolve this problem already on their 70's motorcycles, and steering dampers are common on many brand name sport bikes today.

Some motorcycles/scooters have much less issues than others, depends on rake and general front-end geometry; and then there is the possibility of "wear" of the steering head bearing that is another factor with aging bikes. 

Summary: A good quality front tire "helps to minimize" the problem in the first place, but it is not the only solution to  a wobble problem; it's many factors, as described above.
« Last Edit: March 24, 2015, 02:56:02 PM by windwheeler »

Stig / Major Tom

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Re: Downtown 300i front end wobble
« Reply #18 on: March 24, 2015, 07:45:49 PM »
It amazes me how tire threads and "oil threads" are similar:  Never ending personal "opinions".
 

H e l l o !
Please include: "valve lash checks - hot or cold engine - mandatory or waste of time & $$!. Breaking in the new engine - trash it or baby it. Gasoline octanes. Service intervals. Kevlar vs stock belts. Sliders vs rollers." etc., etc.
When you're new to scootering - and wanting to take good care of your new scooter - forums can be crazy making.
The certified Honda tech who made a house call to my scooter had some amusing thoughts on forum experts.
I smile when I read the remarks from 2-wheel mag columnists regarding bike & scoot 'forums' .

"D o  n o  h a r m."

trying to live that - Stig
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And, I'm feeling a little peculiar.

BettinANDlosing

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Re: Downtown 300i front end wobble
« Reply #19 on: March 24, 2015, 08:02:07 PM »
H e l l o !
Please include: "valve lash checks - hot or cold engine - mandatory or waste of time & $$!. Breaking in the new engine - trash it or baby it. Gasoline octanes. Service intervals. Kevlar vs stock belts. Sliders vs rollers." etc., etc.
When you're new to scootering - and wanting to take good care of your new scooter - forums can be crazy making.
The certified Honda tech who made a house call to my scooter had some amusing thoughts on forum experts.
I smile when I read the remarks from 2-wheel mag columnists regarding bike & scoot 'forums' .

"D o  n o  h a r m."

trying to live that - Stig

Hey, this is America and we're still entitled to our opinions!!!!!
2002 Kymco B&W 300; MRP 78MM "300CC", Naraku cam, Yoshimura rS3 exhaust, 17g Sliders, Yellow torque spring drilled airbox, stock carb #115 main #40 pj.

2001 "Yamaha" Zuma AKA MBK Booster; MHR OverRange, Dellorto 19mm BHBG, Polini "big" intake, RS-3 Rear shock, Stock cylinder.

mrbios

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Re: Downtown 300i front end wobble
« Reply #20 on: March 24, 2015, 10:22:25 PM »
H e l l o !
Please include: "valve lash checks - hot or cold engine - mandatory or waste of time & $$!. Breaking in the new engine - trash it or baby it. Gasoline octanes. Service intervals. Kevlar vs stock belts. Sliders vs rollers." etc., etc.
When you're new to scootering - and wanting to take good care of your new scooter - forums can be crazy making.
"D o  n o  h a r m."
trying to live that - Stig

Stig, you raise very good points and I think there is a distinct difference between solutions or products that work and make a real difference and opinions.  To me style, colors etc are matters of opinion while the trade off between a soft grippy tires at the expensive of high miles falls into the fact vs opinion category.  Fact: tire pressure.  Run low - get a softer ride probably at the expense of gas mileage and tread life.  Is that and acceptable trade off?  That's a matter of opinion and personal goals.

Regarding your list:
Weights flat vs roller: I couldn't tell much of a difference and I'm hoping flat will last longer.  I made the switch around 10K miles to heavier weights to cut rpm's at the expense of acceleration off the line.  At 10K miles my rollers still seemed to work ok and I don't know how many scooter riders in the US will ever ride more than 10K but I do so I lean toward almost any solution that keeps maintenance low.  If I want more power I'll buy a sport bike motorcycle.

Valves:
I've always read cold.  Waste of money?  Yes if the mechanic isn't acutally doing anything.  No if he is really checking and putting them back in spec.

Mandatory?  Usually not.  In college my 1981 yamaha 650 special was supposed to be checked ever 2500? miles.  I bought it used in 1988?  with 14K miles on it no knowing if it ever had been checked.  at around 25K miles the exhaust valve stuck open and the motor had almost no power.  I brought it to a near by ducati dealer and they adjusted it for ~ $30 ($65 inflation adjusted).  It was the screw type like on our scoots and had simple caps for direct access.  That fixed the problem.  I sold the bike a few years later for parts after a crash with a car at around 40K miles.  Most scooters in the use will never see more that 7K miles?  I adjusted my Kymco at 10K and it is running great with 16K on the clock.  Will probably check valves next around 18K.  Same with my 1992 bmw k75 (sold in 2009 with 64K miles still running good).  I had the dealer adjust and was maybe 20K over the check them interval.  Dealer said no problem and said usually intake is fine and exhaust tends to tighten which makes them quieter not louder so ticking is not always a good indicator.

My 1997 Saturn SW2 (original owner). Hydraulic valve lash adjusters (no adjustment needed).  Last year I got the head planed to replace the head gasket.  Machine shop said valves worn less than 10% from original spec and did not recommend a valve job.  Timing chain adjuster show 30% wear with 160K miles.  I have always used generic walmart type oil and change it ever 3K miles and monitor / top off between oil changes.  No doubt synthetic would have reduced the wear but at almost 19 years and the Saturn brand discontinued how much longer does it need to last?  Motor still starts and runs the same as when it was new.

Kevlar vs stock belts:
I've been happy with the first and second stock belt.  I changed it eary at 10K out of "fear" of it breaking even though it appeared to be very good condition and tested well with in speck for width.  I'm mad about paying $85 at the dealer when I could have got an aftermarket Kevlar or otherwise for $50.  Next belt will be aftermarket.  Again, how many people are ever going to exceed 12K? miles when the belt may be worn enough to replace. 

Gasoline Octane:
Here I'm gonna sound like hypocrite.  You know I don't hesitate to flaunt the maintenance schedule by going 2, 3 or even 4x beyond the recommended interval but with gas I believe super reduces denotation and might matter over the long haul.  The scooter takes so little gas I see the cost difference as minor.  I would not shame anyone for running regular especially because most scooter / motorcycle owners in the US prefer their ride parked in the garage (with un-stabilized gas slowly jelling the fuel system) so in most cases what difference does it make.   

Oil: 15w40 @ 1200 miles - I believe it matters (IF you plan to put over 20K miles on your scoot).  AND check the level.  Our scoots only take about 1 qt and it can get low by a few oz after about 400? miles.  Never waste money on synthetic - unless you simply enjoy using top quality oil.

Final note: I ride fast but I don't abuse the clutch /belt etc by revving the engine on a hill at a red light. I take off smooth get full clutch engagement then apply the gas, sometimes to full throttle.  Highway - 80 to 100% to maintain 72 mph to keep with traffic.

« Last Edit: March 24, 2015, 10:32:18 PM by mrbios »
PaulC

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Re: Downtown 300i front end wobble
« Reply #21 on: March 24, 2015, 10:30:05 PM »
My opinion is that this thread is gonna get NASTY!!!!
2002 Kymco B&W 300; MRP 78MM "300CC", Naraku cam, Yoshimura rS3 exhaust, 17g Sliders, Yellow torque spring drilled airbox, stock carb #115 main #40 pj.

2001 "Yamaha" Zuma AKA MBK Booster; MHR OverRange, Dellorto 19mm BHBG, Polini "big" intake, RS-3 Rear shock, Stock cylinder.

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