Aventon Level.2 battery-mounted U lock holder

Abstract

• I wanted to use some otherwise dead space on my downtube

• thankfully the battery cover is easy to take off & reveals aluminum extrusion which with some reverse engineering provides a very strong joint for carrying something as heavy as a u lock

• I wanted open access to the u lock; I'm tired of opening up a bag to get to a u lock & cable underneath all my other stuff

• reduce rattling as much as possible

  • rattling is minimized inside a bag, but the u lock is hard to access

• the stock battery cover does a good job of preventing rainwater from getting into the downtube & battery compartment, which has the controller & other electronics

• additional feature: portage strap mount

  • not yet implemented as of 2024-03-15

  

Early iterations

• used to be a big “cup” without a bottom & a TPU sock

• the TPU sock wound up being way too tight to fit the u lock in

• featured a latch to prevent the lock from jumping out, but being quick to engage the lock by dropping in the lock

Parts by themselves

• the latch was fixed to the “cup” piece with M3 hardware

• not really a great joint, but whatever

Assembled, lock being slid into place

Rev 12

• tested this over about 30 miles with a U lock over a bunch of potholes & it was fine, no breakages or anything

• the upper rain shield has M5 nut pockets for mounting future stuff

Mounted, no U lock in place

• Here you can see how the base piece keys into the aluminum extrusion which is the enclosure for the battery

• to mount the base piece, you must dismount the battery & remove the cover which is held to the plastic ends of the battery cover with qty 2 M3 screws

How the TPU parts are assembled

• there's a sort of dovetail joint at play

• none of the parts require supports

• the TPU parts are folded in & then unfolded to “deploy”

• flanges at either end prevent the TPU parts from moving axially

• M3 screw hole just in case this joint didn't work

2023-10-02 battery lock replacement

• got a spare key to my battery lock

  • tried it, it didn't work

• contacted Aventon support, they eventually sent me a replacement & told me to go to a dealer to have the entire lock assembly replaced on their dime

• did it myself, but fortunately I didn't have to drill it out

  • I removed all the mounting screws for the battery lock & lower bracket, used the spare key, & turned really hard, & the battery unlatched

  • I still wasn't able to actually unlock the lock cylinder

  • after popping out the lock cylinder, I discovered that one of the shear discs doesn't fully retract, preventing me from turning the key, even when the key is fully engaged

Battery details

Hardware

Mounting screws for battery lock & lower bracket

The battery swings into its docked position by pivoting about the lower bracket, which also has the 4 pins for charging the battery. Here is the lower bracket:

Here is the battery lock assembly:

Both the battery lock & the lower bracket mount to the frame using quantity 3 M5 x 10 mm CSK screws, visible here:

In the above image, you can see one of the screws is missing. I believe it is used to mount the plug to its bracket. The screw is an M3 x 10 CSK.

Cable guide

A long piece of aluminum extrusion is used to keep the cables from interfering with the battery as the battery is mounted & dismounted. The extrusion mounts to 2 internally threaded studs welded to the frame using quantity 2 M5 x 12 CSK screws. The extrusion is visible in the previous image. Here are the welded studs (the lower black screw poking through is one of the bottle cage bolts):

Here it is dismounted:

Upon closer inspection, the CSKs are poorly done, leaving a lot of burrs. The holes also aren't round either given how deeply the CSKs are:

I took this opportunity to run an FD cable before mounting the cable guide back in place.

Resources

• this guide was somewhat helpful

  • I loosened the set screw retaining the cylinder assembly, but that didn't fix my problem