Wreck this morning - need ideas on cause for loss of control

[roadrider]

Glad your okey

Did you replace the tire ? or did a shop do the job.
the reason I ask is I had a shop replace my front tire last spring and they forgot to replace the cotter pin in the castle nut on the axle. check yours to see if your front axle came loose.

[roadrider]

Glad your okey

Did you replace the tire ? or did a shop do the job.
the reason I ask is I had a shop replace my front tire last spring and they forgot to replace the cotter pin in the castle nut on the axle. check yours to see if your front axle came loose.

[twinwillows]

http://www.msgroup.org/tip.aspx?num=190

Check out the movie. Twin is this what happened to you?

http://www.triumphrat.net/riding-and...explained.html
Here is good explaination


rick

Rick,

That video shows exactly what I went thru - slight left turn in the road & a slight lean into the curve @ 55mph when a small vibration started which almost instantly went into a full on left/right slap which ended up w/me going off road into the ditch.

It happened so quick that I "think" I let off the gas & may have grabbed the front brake but on that I'm not sure. I'm almost certain that I did not get on the rear break at all.

Here's the bike.

[twinwillows]

Did you replace the tire ? or did a shop do the job.
the reason I ask is I had a shop replace my front tire last spring and they forgot to replace the cotter pin in the castle nut on the axle. check yours to see if your front axle came loose.

I had a shop do the tire changing & I did the reinstall along with reinstalling the front forks after having another shop do the seal & oil change. I followed the manual to the letter including using a torque wrench on all the nuts & installed a new cotter pin when I was all done.

[twinwillows]

Lack of air pressure?

Ken,

Tire pressure was checked 2 days before. We'd had some cold weather & the front was down 2psi so I brought it back up to the rated pressure.

Twin

[twinwillows]

Pretty much anything that upsets the stability of the front wheel can start a gyroscopic wobble that can very quickly turn into a tank slapper. I've had a few wobbles in the 40 odd years i've been on two wheels, and most have the have been caused by spongy tyres.

I can agree in part that a soft front tyre can help start the wobbles.
Would be similar to riding in sand.
I have had bikes wobble and bend under me and not go where I aimed them, but only one tank slapper.
69 500 Kawasaki and 71 Norton Commando. Another bad handling bike was the 650 Yamaha of about the same vintage.
The original poster has not told us if the tyre pressure was low.
With the wobbles we can just keep going, if the speed was not too great, or slow down a bit. A tank slapper requires more immediate attention.
My XS11 is currently doing minor wobbles often. Soon to be fixed.

Crusty[/QUOTE]

Crusty,
How are you going to "fix" your wobbles?

Twin

[twinwillows]

Quite possibly, especially if he has a special.

Guys,

What's this fork brace you speak of? (Yes I have a special).

Twin

[CatatonicBug]

Guys,

What's this fork brace you speak of? (Yes I have a special).

Twin

Member TKat sells a fork brace that is second to none. I understand he can be tricky to get ahold of sometimes though. Check out the thread at the top of the "parts for sale" section.

[b.walker5]

Or check here... http://www.tkat.com/forkbrace.html

[DiverRay]

As an after the fact, I'm glad you came out in "good" condition! As for the bike, I would check the front tire pressure, and the steering stem bearings. They seem to be the #1 and #2 cause of a LOT of problems with these 30 year old bikes. You may have hit something as simple as anti freeze or diesel fuel in the corner that sent you down.
My gut feeling is #1 and#2, though. The Tkat fork brace IS a great thing to add, as it will make a difference in the handling.

[twinwillows]

Diver

I checked the front tire pressure last night, 9 days after the accident, before I pulled it off the trailer & it was right @ 40PSI so I think we can cross this off the list.

Have not yet started to tear down the front end to check those bearings.

I did notice the front wheel is dragging on one of the brakes but that could just be something resulting from the crash & not before. Don't know yet.

Twin