Author Topic: Steering wobble  (Read 2176 times)

dark011

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Steering wobble
« on: October 18, 2012, 08:28:37 PM »
Hi all,
After about a year of ownership and 4,000 happy km, I noticed that the steering on my 300i is getting a bit looser.  As a test, I tried letting go of handlebars, and to my surprise, I had a significant wobble anywhere between ~40km/hr and 60km/hr.  After reading a bit about it, I tried tightening the top steering knuckle bearing yesterday (tip - it can be done with a screwdriver and a hammer through the opening exposed when removing the cover on the right side for adding coolant).  After about quarter of a turn, the steering felt tighter - the suggested test is to get the front wheel off the ground, let it drop to either side (mine always goes to left!) and that it shouldn't bounce (mine was bouncing twice!). Well, today the wobble seems a little bit better, but nit by much.  BTW, I am pretty sure the wheel isn't bent, and I am using the stock tires.
Any similar experiences or suggestions on what to do next?
Thanks,

Kiwiscoot

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Re: Steering wobble
« Reply #1 on: October 25, 2012, 03:33:21 AM »
Quite common on bikes. Caused by tires & dynamics of bike. The screen has a big effect in the case of the Citycom. Mine does the same & seems worse with the big Givi screen, wobble when I let go of the handlebars. One way to tame it is to put heavier bar ends on, but it has not worried me in 46000km of riding my Citycom, as riding with no hands on the handlebars is dangerous in my book.
Interesting about the steering bearing. I just don't know about this bounce test as it seems to me you can over-tighten them to get this "no bounce". Any proper tightened bearing should run free enough to cause a bounce when the streering hits the stops in free-fall like that.. Only way I know of is get bike on centre-stand & backwheel and grabbing forks at the bottom and trying to rock them back & forth. You can feel loose bearings & looking at steering bearing housing you can notice slop.

Over-tightening steering bearings will cause them to run stiff, improve/remove wobble & cause them to wear prematurely. Some scoots like Aprilia Scarabeo 500 has a steering damper to stop wobbles.

Personally I don't worry about the wobbles as it only occurs hands-off. I have wondered if running Dyna beads in the tires will improve it. You could pack some lead washers into the bar-ends for more weight. Harleys have some heavy bar-end weights to stop wobbles in hands-on conditions from what I believe.

Happy Citycomming
Kiwiscoot
Citycom 300i - 46 000+ kms what a blast.
Citycom review: http://scootdawg.proboards.com/index.cgi?board=200cc&action=display&thread=16772

motomataya

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Re: Steering wobble
« Reply #2 on: October 26, 2012, 10:07:06 AM »
With 4000 miles on your tires a hands free wobble is no suprise and not really a problem. I like to run steeringhead bearings snug enough to cause a slow drop when you let go of the bars to each side. To tight will cause the bike to wander around it's lane, and prematurely damage the bearings. The right amount of drag will help with the wobble.

dark011

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Re: Steering wobble
« Reply #3 on: October 26, 2012, 05:34:54 PM »
Thanks for sharing your experiences.  Well, I haven't tightened the bearing any further and will give it the tightness test as suggested by Kiwiscoot.  I am also not concerned about the wobble, since I don't really practice driving hands off.  My concern is that the steering has gotten more twitchy, sort of speak.  With tires inflated to factory settings the response of going over any bumps in the pavement seem to get the scoot to wonder more than before.  I tried playing with tire pressure (I weigh 220 lbs, so I followed Kiwiscoot's advice to increase the pressure slightly), and obviously the steering response changes, bu the increased sensitivity is still there (compared to what the scoot felt like from new to a few 100km ago).  Oh, and I have the big windscreen and box on but that's been the case pretty much since day one, so I don't attribute the wobble to these.

Lomy

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Re: Steering wobble
« Reply #4 on: August 15, 2017, 03:35:03 PM »
I have exactly the same problem. I have a 2012 Sym Firenz 300i and this problem started 2 months ago. I have put a new Pirelli front tyre on but no difference. The wobbling is dangerous and my mechanic has no idea of what to do. Please any help would be nice.

shoupdawg

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Re: Steering wobble
« Reply #5 on: September 13, 2017, 08:27:50 AM »
I recently started changing my own tires.  My Citycom had some pretty bad front tire wobble and when my buddies and I rode with a buddy from out of town, they noticed how bad he was wobbling on the rode whilst he rode my Citycom.  Fast forward to a few weeks ago.  I mounted my own new tire and used a static (vs. dynamic) balancer and it's been really smooth even at low speeds.  Make sure the tire is properly balanced with wheel weights. Don't use dynabeads, etc. in my opinion.

Tromper

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Re: Steering wobble
« Reply #6 on: September 14, 2017, 06:03:50 PM »
A couple folks in the burger forum had some of this recently, they not only tightened the front suspension, & triple tea, but got the handle bar as well.  Seemed to get it.
Beyond that, how are the front wheel bearings? Those do wear out eventually, particularly if you're prone to using a pressure washer on your wheels.
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campurvis

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Re: Steering wobble
« Reply #7 on: September 15, 2017, 02:44:55 AM »
A worn front tire (cupped tread) will also cause steering abnormalities.
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