How to Install the Aventon Throttle Control Unit

If you have an older Aventon bike and you decide to upgrade the Throttle Control Unit (TCU), you may follow this guide. I was able to figure it out and I have a very basic knowledge of electronics. If you can build a computer and wire simple circuits together, you can do this as well.

I performed this project on my Aventon Pace 500 after purchasing the Aventon Color Display & Throttle On Demand Controller Bundle for $185. I think I got ripped off, I can see that others paid less for it, but it is very hard to find and I don't have any regrets. This is my first e-bike, and I had zero instructions to guide me through this install. I searched everywhere on the internet and found only posts about people who asked the manufacturer for instructions that were never received, and I found a couple install guides for the display only, but no one seems to have any info on how to install the TCU. I followed the guides I found to help install the new Color Display (which is a completely separate process from the TCU), and then had to figure out my own way of installing the TCU. That's why I am posting this instructable, to help assure folks like me that they can do it.

• Aventon TCU upgrade kit
• Small philips-head screwdriver
• Wire cutters
• Wire stripper / crimper
• Spade Terminal connectors (or you can use whichever type you prefer).
• Electrical Tape
• Heat shrink wrap/insulation
• Heat gun
• Bike Stand (not necessary, but will make the process easier)

Remove the battery and disconnect the power cable connected to the rear hub. On one end of the battery, you should see a couple screws that keep a plastic casing in place. Remove the screws using the phillips screwdriver. The plastic casing should come off pretty easily. This will expose the current TCU. You can pull it out by hand. You can unplug everything if you want, but I chose to keep it together and take note of which connector goes where. Once you pull it out, you'll notice that the new TCU is about 25% bigger than the old one. Don't worry, it will fit.

At first glance, it will look like all the new cables will simply plug into the old cables, easy-peasy. But no, the battery cables don't match up perfectly. I'm sure an expert would find a way to preserve the yellow connector installed on the new TCU, but I opted to just cut everything off, splice on some spade connectors and called it a day.

This is the point where I completely removed the old TCU. This is pretty easy, but you'll notice that there is one long (about 12") cable that comes through the bike frame: It's the cable that was plugged into the hub. Is not a huge deal pulling it out, but it will be a huge pain getting the new one back through. This is the hardest part of the process. Using a segment of electrical wire fish tape, I connected the hub wire to it using A LOT of electrical tape to ensure it did not pull apart. I'm glad I did, because it took A LOT of force to pull it through the underside of the frame. There is not a lot of space in the hole down there. It will take some patience, and some very precise push/pull action from both sides of the frame opening. You may want to remove the rubber gasket to allow for a slightly wider opening.

Once you get the hub cable through the frame, the rest is easy: just connect all your wires. You will want to shrink wrap the spade connectors to keep them from coming into contact with each other, or, at the very least, wrap them with electrical tape. The rest of the wires are pretty self-explanatory, just line up the arrows and they should easily fit together.

The one cable that didn't fit so well was the hub cable, which worried me especially because it caused the most trouble during installation. Unfortunately, you can't test it without putting it all back together, so I shoved the TCU into place inside of the frame, installed the plastic cap that we removed in step 1, and then installed the battery. The new TCU worked just fine, I could apply the throttle and the bike would go WITHOUT PEDALING (this is the whole point of the upgrade). So I turned off the battery, unplugged the hub cable, and applied some shrink wrap to fix the poor fit of the hub cable connectors. I really wish the cable fit better; for what I paid, it should have. But this will do just fine I suppose.

That's it. Your new bike should be working just fine. There were a few moments where I thought I had connected it wrong, but I was unfamiliar with the new display and was forgetting to turn on the pedal assist (PAS). The old display defaults to level 1 PAS; the new display defaults at level 0, so when I applied throttle it wasn't working at first. I almost took it all apart again, but first decided to mess with the display, where I found that I had not activated the PAS. If I had to do this again, I'd probably install the display first, get familiar with it, and then later on install the TCU.

I hope this helps you and your future riding adventures!