Minimal Assistance Setup for Young Mind/Old Body

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Williemakeit   1 mW

1 mW
Posts: 18
Joined: Nov 14 2021 1:13pm

Minimal Assistance Setup for Young Mind/Old Body

Post by Williemakeit » Dec 29 2021 11:52am

Yes, that's right minimal assistance, so if you are all about speed and power this post is not for you. Now for the few remaining who might be interested in a way to set up an ebike to give you minimal assistance please read on:

First I love the whole idea of an ebike, however I hate that I'm getting old and can't climb hills and ride 60 miles without really suffering (not to mention the need for days of recovery). So as I get older I've resisted getting an ebike as it's an admission that I just don't have it anymore. So the solution for me at this point is an ebike that still make me feel I'm doing most of the work...without killing myself.

I ended up getting a Bafang BBS02 mid-drive thinking I would limit the speed to 12 mph so I would only get assistance when climbing hills. I didn't really know how that would work, but figured since it's assistance levels are programable and I'll figure something out. What I didn't realize was out of the box, the assistance levels already did something close to what I wanted. Reading all the blogs about programming the Bafang, they all seems to focus on setting the assistance levels to make it feel like each level would give give you a gradual power increase with continuous assistance throughout each level. This isn't my first ebike setup, so I figured, why wouldn't this work like that anyway. I understood a torque sensing setup would give you a different feel, but why wouldn't a regular PAS setup work and feel like every other ebike I ever tried. Maybe I'm just dense and didn't realize what was really going on, but after getting it installed and taking my first ride, the light bulb was finally turned on.

As I'm sure many of you know the Bafang program lets you set the Current Limit % and the Speed Limit % for each level. It also lets you set the Keep Current %. Now that I've had a chance to play with those settings, I've realize they allowed me to do something better that I thought possible. The Speed Limit % is the key for me, it allows me to set each level to a speed I need for each situation. See table below.

Level 4 on flat to moderate inclines. This get's me up to 17.5mpr where I can take over and go with no assistance.
Level 3 for small hills or situations where I can maintain between 15-17.5 mph under my own power.
Level 1-2 for steeper hills. This is where I really need the assistance. I use 1 or 2 to keep the power assist at about 250 watts. So I'm still contributing 125-150 human watts.

For the Current Limit %, I've made it proportional, but I think it could all be set to 100% and it would work about the same.
The Keep Current % I have at 60. This tappers back the power as I get near the target speed for that level. So it's not an abrupt cut as you kit the target speed...it's kind of like OK, the motor got you here, now it's time for you to take over.

I have a 17Ah battery and have gone over 100 miles before needing to charge with this setup.
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