Gravity BullseyeMonster LTD with BBHSD and 52V 13.5 ah Panasonic Shark Pack
I started reading about eBikes over Christmas vacation last year and was bitten by the must build it now bug. Between electribke.com and electricbike-blog.com I found all the information I needed. The bike needed to be phat (thanks to electricbike-blog.com...formerly exclusively about electrified phatties) and it needed a mid-drive since I wanted to take it on trails and commute. My main motivator was a head injury a few years ago that prevents me from bicycling like I used to.
The bicycle: Gravity BullseyeMonster LTD from BikesDirect.com -- $599
I started with the Gravity BullseyeMonster LTD. I know it cost a little more than the BullseyeMonster, but I liked the wider tires, tapered head tube and of course the color. The mega bonus with some terrific father-daughter time while we put the bicycle together. I liked riding the bicycle around so much that I held off on buying the motor and battery and doing the build for a while so I could tool around on it.
The motor: Bafang BBSHD 1000W from Lunacycle.com -- $669
After reading many many blog articles, I settled on the BBSHD. I wanted the extra power for trail riding and the motor is newer than the BBS02 so I thought it would likely be around for a while. I bought the 120mm width version because the BullseyeMonster LTD has a 100mm bottom bracket. The toughest part about making the install work was getting the old bottom bracket out and using a rotary tool to smooth out the inside of the bottom bracket as some of the frame parts stuck into it a little. I also dabbed a bit of grease in there to get it to slide in easily.
The tools: bottom bracket removal tool, chain breaker, Luna wrench -- $20/each
I searched for the bottom bracket removal tool all over town and found it at the eighth bicycle shop I stopped at. Later I need a chain breaker and had to run all over town for that as well. It wasn’t until after I’d been to lots of bicycle shops that I realized REI had everything I needed and was a LOT happier to sell me the tools to do the work than the local bike shops were.
I get that they’re just trying to make a living working on bikes, but the whole point of this experience for me was to build it (or break it) myself and ultimately I’d rather buy the tool and learn in a situation like this than pay someone to do it. If you have a local REI, go there, otherwise, save yourself the hassle and order online or…as many have suggest, let the local bike shop do it for you.
Do yourself a favor and buy the right tools and have them on hand before you start, otherwise you’ll end up sucking wind like I was waiting for parts to show up.
I managed to avoid buying the crank removal tool, but will likely end up buying one anyway. I’d like to go back and loctite a couple more bolts that one of the cranks currently blocks. I found the tool locally for around $25…less if you buy it online.
I used the chain breaker to splice in an extra section of chain to get the proper length so I could use the gears on the bike. I don’t need them much for commuting, but they’re a huge help on hills.
The Luna wrench is a must have for tightening up the bits that hold the motor on the bottom bracket. Last time I checked the BBSHD kit, they actually had it listed as an optional tool you can buy--check the box and get it when you get the kit.
The battery: Lunacycles Shark Panasonic 52V Shark Pack -- $475.95
This is where I may have messed up. I bought the 13.5 AH long-range NCRB batteries. These are supposed to be good for distance. I’ve only put about 40 miles or so on the bike so far and the range was in the neighborhood of 25 miles from full charge (I bought the advanced Lunacycles charger -- $100). Most of that was a commute to work…all downhill from my house, all uphill from work. I used quite a lot of pedal assist headed home and the battery meter on the display showed the battery to be a bit under half when I got home…though the final push up the last half mile had it temporarily down to two bars. I took the bike out for a quick ‘round the 4 mile block and pushed it hard trying to kill the battery and succeeded just as I was getting back to my house. Happily it died predictably, not suddenly and after letting it rest a bit, I was able to fire it back up and motor the rest of the way home (with pedal assist).
The reason I say that I may have messed up is that I believe the GA cells would’ve been a better fit for what I want to do. I haven’t had the bike on the trails yet, but after seeing how much power the motor seems to draw going up hill, I believe my range will be significantly diminished once I start riding off-road.
One thing to note--my battery came in a fairly busted up box, but packing inside seemed to be good enough to protect it. Love the unheeded warnings on the outside of the box.
The rest: chain -- $10 from REI, master links --$4 each from REI, XT90S Connectors with pigtails from Lunacycles $6/ea., Luna Eclipse chainring -- $100 from Lunacycles, Spacer kit -- $10 from Lunacycles, Bolts -- $5 from Ace Hardware
I needed a few more things as the chainline was way off when I began assembling everything. I wanted to use the Luna 42t sprocket I received as a free upgrade, but the chain just wouldn’t stay on. After some research it sounded like the Eclipse chainring was the answer, so I ordered that and indeed it does fix the chainline.
I bought the XT90s connectors and soldered those onto the battery mount and the motor after a bunch of reading in the 3-part BBSHD how-to guide on the electribike.com site. The connectors (with pigtails) were fairly easy to install and the shark pack setup means you can remove the battery while you’re doing the work…which means the job is a lot safer.
The stock chain on the Gravity BullseyeMonster LTD was not long enough, so I spliced in almost half of another chain thanks to the folks at REI. This is not ideal as far as I’m concerned and I intend to go back and install a right-sized chain in the future (assuming there’s one out there). Something I learned here is there’s basically two chain sizes…there’s the chains for single speed bicycles and chains for bicycles with more speeds. The difference is the width of the chain.
Fitting the BBSHD to the bottom bracket of the bicycle required some finesse as the rear triangle is very wide. I figured out pretty quickly that I needed an extra spacer kit. I didn't get photos of these, but they're the same spacers that come in the kit...I just needed a few more to get things to work.
The bolts from Ace Hardware were for the mounting plate that must rest against the BB (it loops around it) and then screws into the motor itself. The screws that come with the kit are really long and I’m not sure what they were thinking on those. Luckily Ace had exactly what I needed.
That’s most of it. Nothing was super hard. There’s lots of info here to keep you pointed in the right direction and in the end I have the satisfaction of knowing I did it all myself.
I brought the bike to work and did a show and tell. Now I’m the eBike expert in the department. Hopefully I’ll convince more folks to build eBikes. I’ve already been pointing people towards Lunacycle.com.
The bicycle: Gravity BullseyeMonster LTD from BikesDirect.com -- $599
I started with the Gravity BullseyeMonster LTD. I know it cost a little more than the BullseyeMonster, but I liked the wider tires, tapered head tube and of course the color. The mega bonus with some terrific father-daughter time while we put the bicycle together. I liked riding the bicycle around so much that I held off on buying the motor and battery and doing the build for a while so I could tool around on it.
The motor: Bafang BBSHD 1000W from Lunacycle.com -- $669
After reading many many blog articles, I settled on the BBSHD. I wanted the extra power for trail riding and the motor is newer than the BBS02 so I thought it would likely be around for a while. I bought the 120mm width version because the BullseyeMonster LTD has a 100mm bottom bracket. The toughest part about making the install work was getting the old bottom bracket out and using a rotary tool to smooth out the inside of the bottom bracket as some of the frame parts stuck into it a little. I also dabbed a bit of grease in there to get it to slide in easily.
The tools: bottom bracket removal tool, chain breaker, Luna wrench -- $20/each
I searched for the bottom bracket removal tool all over town and found it at the eighth bicycle shop I stopped at. Later I need a chain breaker and had to run all over town for that as well. It wasn’t until after I’d been to lots of bicycle shops that I realized REI had everything I needed and was a LOT happier to sell me the tools to do the work than the local bike shops were.
I get that they’re just trying to make a living working on bikes, but the whole point of this experience for me was to build it (or break it) myself and ultimately I’d rather buy the tool and learn in a situation like this than pay someone to do it. If you have a local REI, go there, otherwise, save yourself the hassle and order online or…as many have suggest, let the local bike shop do it for you.
Do yourself a favor and buy the right tools and have them on hand before you start, otherwise you’ll end up sucking wind like I was waiting for parts to show up.
I managed to avoid buying the crank removal tool, but will likely end up buying one anyway. I’d like to go back and loctite a couple more bolts that one of the cranks currently blocks. I found the tool locally for around $25…less if you buy it online.
I used the chain breaker to splice in an extra section of chain to get the proper length so I could use the gears on the bike. I don’t need them much for commuting, but they’re a huge help on hills.
The Luna wrench is a must have for tightening up the bits that hold the motor on the bottom bracket. Last time I checked the BBSHD kit, they actually had it listed as an optional tool you can buy--check the box and get it when you get the kit.
The battery: Lunacycles Shark Panasonic 52V Shark Pack -- $475.95
This is where I may have messed up. I bought the 13.5 AH long-range NCRB batteries. These are supposed to be good for distance. I’ve only put about 40 miles or so on the bike so far and the range was in the neighborhood of 25 miles from full charge (I bought the advanced Lunacycles charger -- $100). Most of that was a commute to work…all downhill from my house, all uphill from work. I used quite a lot of pedal assist headed home and the battery meter on the display showed the battery to be a bit under half when I got home…though the final push up the last half mile had it temporarily down to two bars. I took the bike out for a quick ‘round the 4 mile block and pushed it hard trying to kill the battery and succeeded just as I was getting back to my house. Happily it died predictably, not suddenly and after letting it rest a bit, I was able to fire it back up and motor the rest of the way home (with pedal assist).
The reason I say that I may have messed up is that I believe the GA cells would’ve been a better fit for what I want to do. I haven’t had the bike on the trails yet, but after seeing how much power the motor seems to draw going up hill, I believe my range will be significantly diminished once I start riding off-road.
One thing to note--my battery came in a fairly busted up box, but packing inside seemed to be good enough to protect it. Love the unheeded warnings on the outside of the box.
The rest: chain -- $10 from REI, master links --$4 each from REI, XT90S Connectors with pigtails from Lunacycles $6/ea., Luna Eclipse chainring -- $100 from Lunacycles, Spacer kit -- $10 from Lunacycles, Bolts -- $5 from Ace Hardware
I needed a few more things as the chainline was way off when I began assembling everything. I wanted to use the Luna 42t sprocket I received as a free upgrade, but the chain just wouldn’t stay on. After some research it sounded like the Eclipse chainring was the answer, so I ordered that and indeed it does fix the chainline.
I bought the XT90s connectors and soldered those onto the battery mount and the motor after a bunch of reading in the 3-part BBSHD how-to guide on the electribike.com site. The connectors (with pigtails) were fairly easy to install and the shark pack setup means you can remove the battery while you’re doing the work…which means the job is a lot safer.
The stock chain on the Gravity BullseyeMonster LTD was not long enough, so I spliced in almost half of another chain thanks to the folks at REI. This is not ideal as far as I’m concerned and I intend to go back and install a right-sized chain in the future (assuming there’s one out there). Something I learned here is there’s basically two chain sizes…there’s the chains for single speed bicycles and chains for bicycles with more speeds. The difference is the width of the chain.
Fitting the BBSHD to the bottom bracket of the bicycle required some finesse as the rear triangle is very wide. I figured out pretty quickly that I needed an extra spacer kit. I didn't get photos of these, but they're the same spacers that come in the kit...I just needed a few more to get things to work.
The bolts from Ace Hardware were for the mounting plate that must rest against the BB (it loops around it) and then screws into the motor itself. The screws that come with the kit are really long and I’m not sure what they were thinking on those. Luckily Ace had exactly what I needed.
That’s most of it. Nothing was super hard. There’s lots of info here to keep you pointed in the right direction and in the end I have the satisfaction of knowing I did it all myself.
I brought the bike to work and did a show and tell. Now I’m the eBike expert in the department. Hopefully I’ll convince more folks to build eBikes. I’ve already been pointing people towards Lunacycle.com.
Comment