my completed prototype and why its a prototype

[gl1800mike]

I thought those planning a build might like to learn from my mistake. Attached is a pic of my trailer and bike on the test trip to the local bike night.

I hauled it through the local neighborhood on the way as I stopped to show a friend. On the way home I took the freeway and found my problem, a severe weeble wobble at 50 mph. I did a lot of research and I learned that I didn't bias the weight on the tongue enough and I'm getting it corrected. By adding a cooler holder and cooler to the tongue I now have the wobble starting at 65 mph, I plan to add a steel plate just under the front and that should take the problem away.

Not knowing any better I tried to make the trailler basically balanced, unfortunately that was a bad decision. I plan to rebuild the trailer to make a permanent repair after I make one trip with it, if adding the plate of steel biases the thing so it is safe. I also overbuilt so I have seen the light and will make some significant material changes on version 2. see my build pics in the newbie section.

Just to repeat. you need 10% or better tongue weight or you too can be a weeble! I still had a great time building this unit and I completed it in 60 hours. Even with the 2 coats of fiberglass and paint!
Mike

[AlgoDan]

Hey Mike, that's a sweet looking trailer you have. To correct the balancing issue , all you would have to do is move axle farther back. You say you built in 60 hrs. holy cow. I know what you mean by overbuildong, what the heck eh! Good luck and keep us posted on the next one.

[48Rob]

Mike,

Thanks for sharing your experience with us!

Rob

[bobhenry]

Told ya so .........

http://www.tnttt.com/viewtopic.php?f=40&t=54573&p=992915#p992915

You need an exagerated length to slow down the pendelum effect !


Been there done that and yes it scares the crap out of ya don't it ?

[angib]

Much better than adding weight at the front would be to move the axle backwards. Adding weight away from the middle is not a great plan as it just increases the pendulum effect. Sure, it's much, much better to add weight at the front rather than the back (which would make the situation worse), but it's not as good as getting the axle in the right place.

The perfect trailer would have all its weight just forwards of the axle and little or none at the ends. The percentage tongue weight is just guidance and not an end in itself.

[TD Beej]

Moving the Axle back does a few things that help stability. First, moving the axle increases tongue weight, however really what you want is to put the major masses (polar momentum) and center of mass further foward of the axle (tongue weight is a secondary issue), and cuts down the tail weight (penjelum), and it also increases the length between the hitch and the axle (tires and suspension do less work). If you do the other things well you can get by with lower tongue wieghts.
The most important things are to keep the center of mass low and in front of the axle and as centrally located as possilbe. Simply adding tongue weight won't fix stability problems, needs to be added closer to the axle then the hitch to get the maximum benifit. There are some balance calculators online that might help give you the picture, and trailer safety videos. Adding a cooler will help, moving the axle would be better. Good luck and be careful.