Projects / RadMini4 /

Complete Overhaul

Jun. 23 2023

In picking up a RadMini4, my goal was to have a bike that would be a bit easier to transport, but still have the range and style I like.

This bike, with my mods, really ticks the boxes for me. 20x4 fat tires, a dual battery system, and everything is designed to fold up and disassemble easily.

I’ve had the bike in the garage going under upgrades for about two months now, and it has come together pretty nicely.

The bike is kitted out with a 72v system and a Grin Phaserunner + CycleAnalyst combo. Hands down my favorite ebike focused grouping. In these photos, the bike is still using the stock motor, so the power has been limited to 750w, but with a geared motor it still has a good amount of pep.

Here you can see the two battery setup. Both have a simple key-and-slide release setup that makes them very easy to pop off the bike.

On this side, you can see the chain ring that comes with the torque-sensing ERider bottom bracket. In the pictured configuration, I’ve got it setup in cadence mode instead of torque because it’s showing signs of grounding issues (inconsistent power, cuts in and out). I’ll fix that later by connecting the negative line of the battery to the frame (with a VERY small fuse, lol). Doing that has proven to be effective in eliminating signal noise from the PAS device which causes the odd behavior.

At this point it’s performing great and this ride ended up being in the near 35mi range with plenty of power left. It’s very likely this setup can hit 50mi of range without too much trouble.

Planned Upgrades

Moving on there’s still a few things I’d like to improve:

1. Better motor – the stock motor isn’t bad, but I really can’t push it without a temp sensor inside.
2. Better seat – the stock mini seat is…weird.
3. Front basket – I 3d printed a front rack, but I miss a proper basket
4. Rear rack – maybe, not really sure I want one, to be honest
5. Lighting – currently none; really needs a good headlight and at least a solid red tail, if not brake responsive
6. GPS Tracking – duh.

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