Q45 Rack Stabilization

[AronL]

Sharing this here in case it's of interest.

For me, any amount of weight on the proprietary Q45 rack generated annoying and potentially unsafe swaying and rebound at most speeds, and especially down inclines and around curves. With some time, effort, and not much expense -- just like my water bottle cage fix I could (or did ?) post -- I have fixed this.

Both issues were avoidable with better design.

 

[Ramnob42]

Doesn't that negate the function of the swing arm?

 

[AronL]

Doesn't that negate the function of the swing arm?

Uh, what/where is the swing arm ? Or will I find out first time I ride it ?

 

[Greg S]

Uh, what/where is the swing arm ? Or will I find out first time I ride it ?

The swing arm is the lower assembly that the wheel mounts on. By adding a rigid member between that and the rack it won't be able to move up and down to absorb bumps.

 

[AronL]

The swing arm is the lower assembly that the wheel mounts on. By adding a rigid member between that and the rack it won't be able to move up and down to absorb bumps.

Aha. Rendering the shock inoperable then ?

 

[Greg S]

Aha. Rendering the shock inoperable then ?

More or less. My guess is the flexing would break your "fix" reasonably quickly.

Edited to add: and worst case, a large enough bump could cause one or more of your aluminum struts to bend into the spokes - not good!

 

[AronL]

More or less. My guess is the flexing would break your "fix" reasonably quickly.

Edited to add: and worst case, a large enough bump could cause one or more of your aluminum struts to bend into the spokes - not good!

We shall see. There must be a way to improve the significant load/rack sway without unduly compromising shock absorption. Hard to believe former doesn't bother folks (or at least those who've ridden with a rock-solid load on a Blackburn, Old Man Mountain, or similar rack). Thanks

 

[kizarmynot]

I had added a stiffener for a fender and it eventually failed due to flex. You should know right away because those stiffeners will probably make noise as soon as you go over a bump. Here’s a short back and forth on rack wobble.

rear rack wobble

For those that have loaded the rear rack, have you experienced any wobble? I have two rear panniers (about 11 lbs each) and a rear trunk bar (about 7 lbs), bringing the total to just under 30 lbs. When I started my tour the side-to-side movement of the rear rack, even though not huge, was enough...

forum.cruzbike.com

 

[AronL]

I had added a stiffener for a fender and it eventually failed due to flex. You should know right away because those stiffeners will probably make noise as soon as you go over a bump. Here’s a short back and forth on rack wobble.

rear rack wobble

For those that have loaded the rear rack, have you experienced any wobble? I have two rear panniers (about 11 lbs each) and a rear trunk bar (about 7 lbs), bringing the total to just under 30 lbs. When I started my tour the side-to-side movement of the rear rack, even though not huge, was enough...

forum.cruzbike.com

Thanks !! I'm not sure what the pre-loading is but I will look for something to tighten on the shock. I had replaced the shock with something slightly stiffer but maybe if pre-loading/tightening doesn't do enough I will find/buy/install an even stiffer one.