Specialized Fatboy BBSHD / ASI Bac 800

[CaptainCodswallop]

Hey all, pretty new here but thought I'd share my BBSHD fatboy that I have been working on for over a year now. I have about 3000km on the motor including 1000ish with the ASI external controller.

It hits 60kph max on the flat on a 52volt battery (only when full) Range is about 40-50 km on a 25.4 amp hour triangle pack. Acceleration is extremely good. It will hold 45kph even up 9-10% hills when needed.

Gearing is 1:1 ratio 42 tooth front and rear. Bike is stock unit from 2017.

There are a bunch of videos on what I have done and riding it around etc at https://www.youtube.com/channel/UCIwEj8 ... fR2VCkHRmw

It's still a work in progress but then when isn't anything lol

Cheers

[Downshift100]

Do you need the gear sensor any more?

[CaptainCodswallop]

It's a bit redundant now as I fixed the derailleur to one gear. Even before it was fairly useless as I was using the 50 watts the BAC 800s engagement mechanism to change gears. It pushes a low amount of watts to keep the chain tight. It also did a nice job of switching gears without stress.

[intramorph]

What did you put in place of the stock controller? just some 3D printed part?

[CaptainCodswallop]

Yeah the kit I bought came with a printed cover. It's ok. Not very strong but good enough to seal against the weather. I'll probably make my own eventually.

[joost]

Hey! Built a mid fat with the same combo. The ASI turns makes really makes the bike lively. Paas became unstable so I just ordered the egg riderv2 in hopes of getting the paas back. I still like to do some pedaling.

[CaptainCodswallop]

The eggrider will give you pas back. Message me when you get it and I can give you the correct firmware you will need

[RideFat]

Hello. I am just about to embark upon a conversion of a stock fatboy 2017 (with the QR dropouts).

I noticed you used the 120 size HD motor. The Fatboy BB is 100mm.

Will the 100mm fit with the chain stays? My hope is that I can retain some reasonable chain line.

Thank you.

[CaptainCodswallop]

Hey Ridefat the 100mm will not fit with the fatboy as the bbshd motor housing will not then clear the chain stays. you need the 120mm. But you can get good chainline with the 42 tooth bling ring and switching the gears around on the rear sprocket. Get one that breaks apart...

https://youtu.be/e3THcwfcP-8

[RideFat]

Here is my build.

Stock fatboy 2017 (with the QR dropouts) Carbon Fork and a dropper post I added. 1X10 speed to start.

28T gear. Same as original drive train. I have ridden it with 42T and is fast(er).
Used Trip Wire brake sensors
Many zip ties
Some liquid electrical tape to water proof gear sensor and where wires go into housing
Left Hand Throttle (I tried a right hand twist and do not recommend for a bicycle)
Mini display
52V wolf pack battery

I can hit all 10 gears. Its a tough chain line for the low gear, but it hangs on (and climbs like a MF)
Up to 30+mph
Range is more than acceptable for my needs

120mm width motor. I have used spacers on the left to get the motor close as possible to chain stay. Will eventually change to a steel spacer. Guessing about 6mm in spacers. I did not see another way to make this work... Having too much fun to wonder if I could have gotten away with the 100m motor :)

[joost]

Really nice and clean install from out the gate! I have a midfat but not quite as pretty as this one.

[CaptainCodswallop]

I love it! Orange looks great! Good job on the build!

[lg-39]

Hi captain :) Tks for your answer on youtube !
With 52v 33A (1700w) you reach 50kph on ratio 1:1. Very impressive ! 50kph with 26X4P tire = 350 rpm motor :)

I would like to build the same ebike as on my Avatar (It is the Patrick1977 bike) with 74v + Luna mini 30T with 3v 30/36/42T speed.

Had you problems with your chain or rear gear when you was used your multi-speed sprocket at 33A continuous ? Is the 50w ASI mecanism effective ?
I hope to have correct chainline with Luna 30T and 3V and 33A continuous.

Good ride

[CaptainCodswallop]

The 50 watt engagement changed gears very well. Its locked now though. But if I hadn't damaged it a 3 speed would have been cool.

[lg-39]

Tks very much. How do you damaged it ? I dont know how work the mecanism...

[CaptainCodswallop]

I think it was just the stress. The set screw that holds the derailleur above the gears got worn so I fixed it in place with a m4 bolt and washers.

[EricDtor]

Captain! Been subscribed to your youtube channel for awhile now. Would you still recommend the ASI BAC over stock controller now that you've been running it for awhile now?

[CaptainCodswallop]

I'd recommend anything over the stock one lol. But the ASI plug and play is a good option for sure.