Front End Wobble

[grubsie]

Something happened yesterday while my wife and I were out for a ride. We were traveling around 40 mph around a blind corner when my front tire, then rear tire, got swallowed by a large rut across the road. Damn near almost lost control. At one point, my hands came off the handlebars. We really hit hard. I have no idea how we didn't crash. My arms and shoulders are very sore today. We hit so hard that the front fender mounts on the fork lowers dented the lower fork tins.

 

Anyway, didn't notice anything afterwards yesterday, but today when I took the bike out, I noticed that something didn't feel quite right at slow speeds. At anything under 25mph, if I take my hands off the bars, the front end wobbles but doesn't feel like it is wobbling while my hands are on the bars. It just feels not right like it's tight. Especially in corners.

 

Above 35 and beyond, it feels fine. I took the bike out on the highway and took my hands off the handlebars at different speeds with the highest I dared at 70mph and no wobble and the bike felt normal. I took the bike up to 105mph and it felt great.

 

As soon as I got off the highway and down to slow speeds the handlebars would start to wobble again when I took my hands off them.

 

What I did so far.

 

Looked the front end over closely to see if anything is bent. Took all kinds of measurements and everything looks fine.

 

Checked the the front and rear suspension air pressure and they both checked out fine. Same with the tire pressures.

Put the bike on a lift and checked to see if there was any play in the steering neck. Checked out fine.

 

Strapped my dial indicator to the forks to check to see if the wheel ran true. Checked out OK a couple thousanths max which is more than acceptable. Did the same to the back and the rear wheel checked out OK too.

 

Then checked out the runout of both wheels with highly technical jigs holding straws to see if the wheels were out of round. They checked out OK also. The rims look fine also.

 

So now my thinking after this process of elimination is to take both tires to the local dealer to check the tire balances. My thinking is maybe a weight came off one or both tires on impact since we hit so hard.

 

Think I am on the right track? Anything else I should check out?

[XV1100SE]

2nd Gen ? When was the last time you checked to make sure your steering head wasn't loose. The wobble "hands free" is an indicator of a loose steering head.

 

See the write-up in the 2nd Gen read only section. Some say to use the "bounce test" but I find it more reliable to lift the bike, turn the wheel 45 degrees to the left (right the cables bind and don't dive an accurate test). Hold the wheel still at 45 degrees and then just let go. If the wheel falls to the left, your steering head is too loose. When you let go it should hold it's position.

 

I check mine every 10-12,000 km and typically have to adjust it.

[grubsie]

2nd Gen ? When was the last time you checked to make sure your steering head wasn't loose. The wobble "hands free" is an indicator of a loose steering head.

 

See the write-up in the 2nd Gen read only section. Some say to use the "bounce test" but I find it more reliable to lift the bike, turn the wheel 45 degrees to the left (right the cables bind and don't dive an accurate test). Hold the wheel still at 45 degrees and then just let go. If the wheel falls to the left, your steering head is too loose. When you let go it should hold it's position.

 

I check mine every 10-12,000 km and typically have to adjust it.

 

Yeah, 2nd Gen. Did the front end flop test and it holds steady. Should have mentioned that in my 1st post. Everything was fine until the impact yesterday. Loose steering head bearings come on slowly.

[Du-Rron]

We hit so hard that the front fender mounts on the fork lowers dented the lower fork tins.

 

 

Bent Forks.

[OrlinEngh]

We hit a very deep pot hole a couple of years ago, and had the same thing going on, it hit hard enough that it put flat spots on the steering head bearings. Not sure if hitting the hole caused it or not but I also had to replace the front wheel bearings with a 1,000 miles,

[vzuden]

So now my thinking after this process of elimination is to take both tires to the local dealer to check the tire balances. My thinking is maybe a weight came off one or both tires on impact since we hit so hard.

 

Wheel balance comes into play only at 40-45MPH + since that is when the centrifugal forces take over. I suspect steering head bearing issue

[cowpuc]

I had the same thing happen years ago and spent some time figuring out what was going on.. In the end,, I discovered that the sharp edge of the pot hole I had hit actually caused belt slippage/damage in my tires.. Finding this required me to raise the bike, wack the brake calipers with a rubber mallet hard enough that I could back the caliper pistons off enough that the wheel would spin free and then spin the tire and watch for lateral movement in the tire.

Belt slippage is not uncommon in car tires, just occasionally watch cars when they are in front of you and you may also notice a tire on one of them moving slightly side to side. Fortunately in a car, this slippage can usually just barely be felt (a lot of folks dont even realize they have an issue) and is not discovered until the tire goes flat from air leak around the damaged area..

Since discovering that bike tires are vulnerable to the same flaws or damage, I have had several instances of belt damage thru the years and now know to check them closely when experiencing an incident like you bring up..

Also,, while your checking the tires, watch your rims very closely too as rim damage is also not uncommon after nailing a sharp edged pot hole like you describe..

Wanna hear a short funny story about something similar to your situation? Ok,, read on..

Years ago I was out playing Destry Abbott (iconic KX500 Baja racer) on my own KX500 here in Michigan.. While CTFW in the dirt at speeds in excess of 80 mph I nailed a hidden tree root while jumping from a huge pot hole on a two track. The tree root lofted my scoot clearing some 130 feet of air/distance before touching back down (no joke - I actually paced it off).. After I landed from the launch, I got off my bike, leaned it up on its side stand (after market) and against a tree and spun the front tire = 4 inch long bend in the front wheel,, rear wheel had a matching bend!! When removing the tires to pull the spokes to lace on some new wheels I noticed that my Dunlop "52's" had taken so much impact that they too had been cut thru on the beads from the impact!!! CHECK THOSE TIRES CLOSELY GRUBBY = you dont want to experience a flat tire ride now to go along with the pot hole experience,, IMHO of course..

[MikeWa]

Sounds like you may have damaged a tire.

 

Mike

[grubsie]

And the winners is...........

cowpuc!

 

Brought both wheels to the dealer yesterday afternoon. Just got a call that the front tire is junk, rear is fine. Arrrg! Brand new Avon Cobras this spring with only 5900 miles on them now. They only have Dunlops in stock so I am having them install one so I can ride out the year on it. Something about the sidewalls and the tire not balancing properly. I will look at it when I pick up the wheels.

 

Still better than all the hours involved in tearing the front end apart to replace the steering head bearings.

[grubsie]

Got the wheels back this afternoon with the new Dunlop on the front. Put them back on the bike and took it for a quick spin. All is back to normal.

The damaged tire was a mess. Didn't notice it on the rim but the rubber was split almost all the way through behind the rim lip on the right side of the bike and the left side was split on the inside of the tire on the left. They said they have never seen a tire like that without rim damage. Surprised it held air. Glad it was changed before I experienced a serious blowout.