Making better supports for a rear rack

Jason Knight

Active Member
Region
USA
City
Keene, NH
Despite having added lock washers, thread lock, and a host of other "fixes" the rear rack on my e-bike let go yesterday. Had to do the wonderful "ride home with it held in place with bungee cords" routine. Whilst the blackburn rack fit the bike's width perfectly, like all of these racks the way the front arms attach is a joke.

There's a reason I didn't get the one Aventon sells for the bike.

Whilst the arms for the bike were sturdy, this "drive a screw down on the arm and HOPE it holds" rubbish is the type of dipshit "eye cans haz enjinearing" chazerei I've come to expect from the industry as a whole.

So...
rackArms.jpg


The mounts for where the rack arms attach to the bike were 1/4" diameter 20tpi threaded. If 1/4" is tough enough to hold it there, it's tough enough to hold the whole thing. Thus I went and bought two 1/4" threaded rods, two 1/4" couples to attach the rods to the mounts, a pair of turnbuckles so I could make the length adjustable -- which came with eye hooks already in it -- and some locking washers, spacers, and 1/4" screws and nuts to attach one of those eye-hooks to the rack. And since I have a giant box of them, pulled a pair of p-clamps to attach the rack to the new arms.

Originally I was going to cut longer rod to the exact length -- that's the plan I went into the hardware store with -- but when I saw the turnbuckles inspiration set in. 1 foot long pieces of threaded rod are dirt cheap, no cutting needed. One side of a turnbuckle is always reverse threaded, but it was easy enough to find a pair where one side was normal 20tpi 1/4".

Liberal amounts of red "permanent" threadlock was applied.

I'm arguing with myself over if I'm going to take them back off and paint them. How they are now was supposed to be a test fit, but I kind of like the industrial look of the bare metal.

All the parts are either stainless or zinc plated, so the worst that happens is they go dull in finish so long as I keep them out of high corrosion environments. Funny thing that, stainless does rust slower in lowly corrosive environments like air. You get salt water on them even cast iron lasts longer. Part of why naval vessels use sacrificial anodes. They do go ugly I can always sand, acid bath, and then paint them... or just replace with new since it wasn't bank-busting.

Very simple solution, actually seems a stronger fitting than anything else I've dealt with. Friction fits for something you're going to put weight on is just dumbass, and yet seems to be the norm for any and all rear-racks that aren't custom fit to a specific bike. And it wasn't even $18 worth of parts at the hardware store. And I was even able to use the stock mounting holes on my Aventure instead of the p-clamps I was using on the seat-stays.

Here's another pic.

rackArms2.jpg


The turnbuckles making it adjustable was the icing on the cake. Once leveled a drop of threadlock stops vibration from changing 'em.

While in there I swapped off the cheap panniers I had for the more durable set off my old cruiser. It's sad when "Bell" is the more durable brand.