2020 Giant Escape + Bafang BBS02

Hey all! I am new as a member but have been lurking for the past few months trying to gather information about the best build to suit my needs.

I started this project first with a budget of $1500. I went a little over by the time the shift sensor and Lekkie Bling Ring were purchased. It costed about $1650 after everything was fully completed.

About Me
I am an avid amateur cyclist that lives and commutes in Denver on a daily basis. I mostly built this to help me ride through the winter and less than perfect days, so if I do get caught in the weather, it will be much easier to wear rain/snow gear without needing to pedal efficiently. Try to picture pedaling in snow pants!

The Bike
Is the best spec'ed one that I could find under at the $600 mark. Aluminum frame with hydraulic brakes, decent mid level shimano drivetrain, and all the appropriate mounts for fenders and a rack. Giant makes an Escape model that comes with fenders/rack/kickstand preinstalled but was a little out of my budget. The only thing that I would have like this bike to have is Thru-axles, but I figured I could upgrade the fork next year to something stiffer with thru-axles if the QR's are an issue. Fenders were mandatory for my build since I will ride this year round and I think it will keep the motor/wiring much cleaner.

The Juice
Comes from a Bafang BBS02. I have it hooked to the tiny 500c display and powered by a 48v 17.5ah "Shark" battery pack. I have reprogrammed the controller almost as if it were and IGH hub. My max current is set to 18amps and start current is set to 10%. I have all but the highest PAS level set to 85% Speed (rpm) Limit - Taking into consideration what rpm DC motors are most efficient, I have gotten the most range and natural power production with these settings. It puts me at about 100rpm shift point where the power begins to cut out. I have 5 PAS levels with 0 being throttle only, 1 being 60% Current to Level 5 being 100% current. I mostly use the level 1 PAS, I only bump it up as my battery discharges in an attempt to draw consistent watts whether the battery is at 52v or 43V. It has worked so far and I enjoy the consistent feeling of it.

The Speed/Range
Before anyone tells me that my range and speed I get out of this motor is exaggerated.....I am an avid cyclist and am able to maintain 20mph on flat ground on a proper road bike for about an hour.
I routinely cruise with PAS about 25-28mph, according to the 500c screen, this speed for me pulls about 350 watts. I weigh 150#'s with the bike weighing another 45# or so. I only use the throttle to get a quick start if I need to cross a busy intersection or pulling away from a light with cars behind me. If I keep it around 25mph, I get just about 65miles per charge. I have programmed the controller to ramp power very gently so am using quite a bit of leg power to accelerate to about 13mph before the motor really kicks in. I also stop pedaling early and try to coast gently to stops as much as possible to extend range. No use just eating up battery and brake pads!
With the throttle (and pedaling) and in the highest gear 42t : 11t, I have reached 34.5mph. This is scary fast on a bicycle!

Overall, I am very happy with the build but think I could have gotten a smaller battery pack and still be satisfied with this range! I will report on the long term reliability and am most curious to see how often I need to replace the consumable parts to start logging appropriate maintenance intervals.

An alternative to thru axels is a solid axel. You can get them from ebay, wheels manufacturing or AliExpress. I’ve even been able to swap up to 10mm dia in the front up from 9mm. I try to stick to metric 10mm x 1mm thread pitch. 3/8” is available and prob ok if you use matching nuts. I use the nuts with a built in washer as to be able to really crank them down w/o scratching up your dropouts. Make sure you get the type of axel for the bearings you have, either loose or sealed bearing cartilage. I’ve had cartilage bearings on the threads of the axel before and it’s a loose fit. This setup is good to help prevent wheel theft as opposed to quick release but if your prone to flats or take your wheels off to travel or whatever they may prove an inconvenience as your wheels will require a wrench to remove, sometimes two wrenches.

https://wheelsmfg.com/products/hub-parts/all-axles.html

AyeWattsUp said:

Hey all! I am new as a member but have been lurking for the past few months trying to gather information about the best build to suit my needs. [...]

Overall, I am very happy with the build but think I could have gotten a smaller battery pack and still be satisfied with this range! I will report on the long term reliability and am most curious to see how often I need to replace the consumable parts to start logging appropriate maintenance intervals.

Click to expand...

Hey AyeWattsUp - Firstly, I like your build a lot. :thumb: Great balance of value, effort, and result in my opinion. How is it treating you? Is it working as you envisioned? I considered doing something exactly like what you did. But, I ended up trading time for money, and bought a bike that someone else (i.e. a factory in China) built for me and solved whatever needed to be solved... but I wont have my new bike until April (has to be built, then it goes on the slow boat to the US).

Looks very nice! Would you tell more about your programming? I find that my ideal pedal cadence is substantially slower than the motor's most efficient RPM, but don't know how programming can help since they are both coupled by the same drive train. Does your programming change address this?