Hey guys,

This last week I guy that I often ride with lost control and crashed in a corner on the way to sturgis. Unfortunately hes not longer with us, but the crash was considered to be a mechanical failure because his bike had been wobbling in corners prior to this happening he just hadnt figured out what it was yet.

That being said i have a similar wobble when i corner on my roadstar and after this turn of events i REALLY want to figure out what the issue is. I just changed the tires and asked the shop to look into the wobble as in swing arm/wheel/shock... but they told me they "didnt see anything wrong" whatever that means. I know i need a shock because when i load up or ride 2 up its sits down too low and i drag pipes and boards way to easy but i dont know if that would neccessarily creat a wobble.

My dad seems to thing that its bushings in the swing arm so i might do that and a shock and see what happens but I thought i would post up here and see what the forums expert advise and expirience had to say about the wobbling issue.

roadhammer

Sorry to hear about your loss, wish we never had to read about these things. I'm not much of a wrench so my first thought would be tires.

I read about a couple that didn't make the trip to Sturgis, and I know a few were from Wisconsin. Sorry for your loss. I would take the bike to another shop, don't tell them what is wrong, just ask them to "Inspect" the rear suspension, tires, and bearings. See if they find anything. A lot of shops will "Test drive" too, but if they are not familiar with a bike, they might not notice anything as being out of the normal.

I'd look at tires first BUT there is a huge consideration that many never consider. That is the amount of weight we are putting on our ride. That amount can effect the handling of your bike drastically!!

I pulled some numbers from a road test of an 08 Road Star. Wet weight was 752 and it has a GVWR of 1164 so you only have 412 pounds of passengers and load you are supposed to put on there. I go 235 and the wife 130 so that leaves us 47 pounds TOTAL for accessories and gear. Now think about it, this is a stock Roadie....no hard bags, back rests, fairing, stereo, chrome and so on. Now tell me many of you don't ride around overloaded all the time!

Its a fact of life with most bikes that we run at or over the weight rating all the time. Its my opinion that it is a big contributing factor to accidents and some mechanical issues. I know most of the wrecks I've seen somebody usually is going in to a turn and either grounds his bike which stands it back up or went in too hot in the first place. Try to imagine running your pickup or car right at its weight limit all the time. do you think it would handle and perform the way you would like? It's one of the reasons back in the day we stripped our bikes and didn't add to them (like what I have done to mine). Yes, less "comfort" but much better performance in every dimension including safety.

While I have no knowldege of your particular situation I'd look at tires, the whole drivetrain if you believe the wobble is located in the rear and the weight.

Sorry about your friend and always hate to hear about these kinds of accidents.

When cornering the motorcycle in effect has a hinge in the middle that can affect handling a great deal the Steering head. A weak shock, or over loading will make the bike feel spongy, maybe wobbly, but in need of additional firmness. I would look first at the hinge I refered to earlier, the steering head bearings. When a scoot is leaned the a wobble is more probable from a side to side movement of the steering head and a small movement at the pivot point can translate to a large movement at the contact point. Wobbles can also be from badly worn swing arm bushings, but that wobble is usually felt at other times too.
1. Check tires for uneven tread wear and proper inflation, generally at least 38 front 40 rear and more if you are loaded up.
2. Check steering head bearings for play and torque or replace if needed
3. Check swing arm bushings for wear and play side to side.
4. Check shock mount for cracks and shock for leaks (probably won't lead to a wobble, but can make for a spongy out of control in corners feel)
5. Check spring preload and increase if you ride heavy a lot or replace with a heavier spring.

If all that does not work, I am out of ideas.

Do everything Cruserbob said PLUS make sure your rear tire is aligned with the front tire. If it is scud to one side it will cause a wobble.

takehikes

I'd look at tires first BUT there is a huge consideration that many never consider. That is the amount of weight we are putting on our ride. That amount can effect the handling of your bike drastically!!

I pulled some numbers from a road test of an 08 Road Star. Wet weight was 752 and it has a GVWR of 1164 so you only have 412 pounds of passengers and load you are supposed to put on there. I go 235 and the wife 130 so that leaves us 47 pounds TOTAL for accessories and gear. Now think about it, this is a stock Roadie....no hard bags, back rests, fairing, stereo, chrome and so on. Now tell me many of you don't ride around overloaded all the time!

Its a fact of life with most bikes that we run at or over the weight rating all the time. Its my opinion that it is a big contributing factor to accidents and some mechanical issues. I know most of the wrecks I've seen somebody usually is going in to a turn and either grounds his bike which stands it back up or went in too hot in the first place. Try to imagine running your pickup or car right at its weight limit all the time. do you think it would handle and perform the way you would like? It's one of the reasons back in the day we stripped our bikes and didn't add to them (like what I have done to mine). Yes, less "comfort" but much better performance in every dimension including safety.

While I have no knowldege of your particular situation I'd look at tires, the whole drivetrain if you believe the wobble is located in the rear and the weight.


I am glad you pointed this out. I am a big boy, and have often wondered if 2 up and an agressive riding style especially in corners may be pushing it a little just from the weight perspective. I definitely think there is something to be said for keeping weight in the back of your mind.

Curt wrote:
Do everything Cruserbob said PLUS make sure your rear tire is aligned with the front tire. If it is scud to one side it will cause a wobble.

agree....out of curiosity Curt, what is your recommended method for checking this. I know I have tried several, curious what yours is.

I had heard that his tire blew unless that was another rider. Sorry to hear.

A worn shock can cause "wobble" while in a turn due to force dynamics.

Remove the shock and check out the shock frame mounts for cracks or bent steel.

I would replace the shock and spring and check out the bearings per the service manual.

Check your alignment by measuring from the axle to the swing arm. Make sure you measure to/from the same place on the swing arm and center of axle.

Ray

I have two 8 foot pieces of steel angle I jack the bike up until the tires just touch the ground. Then I clamp the angles one on each side on the rear wheel and check to see where the front lines up. I also pop the covers off the swing arm bolt and measure from the center of the swing arm bolt to the center of the rear axle on each side they should both measure the same. After that you can jack it up till rear is off the ground and check the swing arm bearings for play.