New trunk for the Avenger II

[LukeM]

I made an aluminum luggage rack for my bike some time ago, and used a square Emgo-brand box for holding helmet, or tools, or a couple bags of groceries.  It looked a bit small for my Shadow, so I went looking around for something more appropriate.

Here's what I found:


It took a bit to get the mounting bolts in the right places, but I eventually got it. It holds 2 full size helmets, or my helmet and my riding jacket. Cost of the trunk was about $30 on EBay with $20 shipping. It's a Givi clone, but I couldn't drop $200 or so on the name-brand item.

So far, it works well. Balances out nicely when I'm on the bike, and holds what it needs to.

Next stop: hard saddlebags, maybe?

Luke M

[shinyribs]

I used to cringe whenever I saw any type of luggage strapped on to a bike. Now I appreciate the freedom it allows.

Nice rig,Boss!

[LukeM]

I noticed something when I rode the bike earlier this week.  I had my backpack with about 10 pounds of laptop and cables and stuff in the trunk.  Riding at about 30 mph, I went to adjust one of the mirrors, and noticed a little wiggle in the bars.  Just for grins, I took both hands off the bars, and saw the beginnings of tank slapping: the bars slowly and gradually moving from side to side.  I pulled over, and put the backpack on my back, and rode at the same speed.  No wiggle.

I remember this happening in my bicycle riding days with extra weight over the front wheel. Any little out of balance condition is exaggerated with that extra weight.

I am curious as to why I didn't notice this with the smaller trunk I had on there before.  Maybe I don't ride no-handed enough?  Maybe it's better to put the weight lower on the bike? Maybe a steering stabilizer on the front forks to damp out the oscillation?

Luke M

[sgtslag]

Your trunk is outside of the load triangle:  draw a straight line between wheel axles (base of triangle), then draw two lines up, to form the top of the triangle over the gas tank area.  Ideally, your weight (riders + luggage) should be inside the triangle's lines.  All trunks fall outside of the load triangle, even on heavy touring machines -- all modern touring machines, with OEM trunks, have warning labels inside warning not to put more than 10-15 lbs. in them...  Exceeding their weight recommendation will cause the bike to become unbalanced, and dangerous to ride.

Saddlebags will almost always fall inside the triangle's lines, so this is where the heavy stuff should be placed, with light-weight items being put into the trunk.  A tank bag is smack in the middle of the load triangle, so you can put heavy items inside of them, and balance won't be affected, but your gas tank might bend under too much weight.    And you have to remove that bag every time you fill up, so keep that in mind, as well.

Your backpack, with a 30-lb. laptop inside of it, was near the center of the load triangle, while it was strapped to your back, which is why the bike ran/balanced normally.  Reinforcing the front fork tubes will stabilize the front end, but it won't stop the heavy load inside your trunk, from unbalancing your bike.  Cheers!

[motogrady]

rear springs set on stiffest setting maybe help a bit?

[Truck]

Stiffness wouldn't be your problem, it's weight distribution. and weight beyond the rear wheel will act like a counterweight and lighten the front end. The farther out from the wheel, the greater the impact. think of a tetertotter. Put a fat kid on one side, its going to lift up the skinny kid.

[LukeM]

Agreed.  After thinking about it a bit, you are correct.  It was just a bit surprising to experience it.

A 30 pound laptop?  Nahhh...more like 10 pounds or so.

The rears are already set to the next to hardest setting.  

Thanks for the input.  You learn something every day.
Luke M