Batteries & Babbling

Up until recently, I've been fairly comitted to using LiFePO4 batteries. I was leaning toward ThunderSky 60AH, but the physical layout of the cells didn't look great in my mockup. Maybe one of the other suppliers would work better?

Therin lies the problem. Distribution channels for Lithium batteries are not established in the US. Sure there are dozens of people who will import them, but I'm not a big fan plopping down thousands of dollars for a product without support .

The only brands actually being sold in the US are from overseas based companies. The US based manufacturers won't even sell their batteries to a non-OEM manufacturer. Sure, they have a link on thier website to "tell us about your application", but what they really are looking for is someone ready to place a $500,000 order and wait a year for the product. I've exchanged emails with A123, Valence and EnerDel, just looking for more information, only to get the go-jump-in-a-lake reply. (In hindsite, I may have replied a little hastily to those emails.....)

The asian suppliers have thier issues too. ThunderSky doesn't have a decent BMS system, while LifeBatts are built-in and slick but very spendy. Interestingly enough, I have written to both and gotten prompt, informative replies.

So, I'm really stuck. Normally an EV conversion hinges on battery selection, and fitting the trays around them. What if my trays are more generic, allowing for multiple battery formats? It's easy to add spacers or mounting holes after the battery selection is made.

The key is still optimizing the use of space for batteries within the frame. So I still needed to grind a few thing off the lower frame rails. (For comparison, see the cardboard mockup, several posts back)

Diversion into detailing

I know, I know..... I'm supposed to be mapping the frame geometry and working on the solid model. Unfortunately, other things (that pay the bills) have been dominating my time latley.


I did have a little time to sneak out to the garage and do some detailing on the frame, and experimenting with polishing various surfaces. I'm toying with the idea of turning this bike into a "street figher", because I can't bear covering up the frame.

The frame is an intricate combination of sand castings, die castings and extruded sections. Most of the less visible castings were not cleaned up very well, with rough parting lines, and even sprues still attached.



The steering head is a large sand casting and really needs some help. The sprue remnants were driving me crazy (have you picked up on the anal retentive tendancies), so I ground them off. I then used progressively finer sandpapers on the surrounding cast surface, and finished up with some 000 steel wool, and some Mother's aluminum polish.

The results aren't quite "mirror-finish", but pretty good for a rookie, IMHO. I may need to go one grade higher on the sandpaper and do "00" and then "0000" with the steel wool.

Hopefully, I will be able to get away for few hours sometime this week to get the dimensional layout done.

Stripped Naked

I finished removing the front end tonight. Now it's just a frame and a welded sub-frame. The frame feels a lot lighter than it looks. I'm guessing around 30 lbs, but I will weigh it to be sure.

Why strip the frame completely? Isn't that overkill, just for an EV conversion?

Well, now the fun begins: reverse engineering the bike. The next few weeks will be spent measuring the frame geometry in order to build a 3D cad model.

GSXR 750 Swing Arm Removal

Time to remove the rear end of the Gixxer. After some second class carpentry to create a stand, I was ready to remove the rear end.

The upper mount of the shock was attached to the frame by four socket head cap screws threaded into the strut between the frame rails. I've never seen so much lock-tite in my life. Aluminum threads are notorious for tearing, so I reluctantly used a 16" piece of pipe to extend the leverage on my allen wrench. Even after breaking them loose, it took a lot of force to back them out.

The swingarm pivot shaft came out easily, but the swing arm remained in place, because of a threaded spacer. I browsed some Gixxer forums, and learned my options were to buy a specialty tool ($$), use a hammer and screw driver (ouch), or make my own tool.

My tool consists of a 5/32 hex wrench, ground to fit between points in a 32mm socket. Note the angled ends of the hex wrench. Worked like a charm.

Battery and Motor Mock Up

According to my research, every EV project has to do a cardboard mockup of the engine and battery placement. The point of the mockup is to get a good idea of what is going to fit, and what is just not going to work out.

Even though I'm planning on replicating the frame in a solid modeling program, I thought it was a worthwhile exercise, revealing a couple of potential problems. Note the can of Sherwin-Williams finest representing the motor (same diameter as a D&D or Advanced DC).

My first cardboard revelation was that it's a lot tighter fit than I thought it would be. I modeled the 60AH ThunderSky batteries, but they are a smidge too big to fit in some orientations. The second eye opener was that a few of the original mounting lugs will need to be ground off, to let the batteries sit higher. I hate to grind anything off, but there is just no way to utilize the space between the frame rails without doing it. I think the remaining lugs will be sufficient to hold the motor and battery frame.

The motor will fit decently, assuming I use an ADC or D&D type. The paint can is 6.75" in diameter, compared to 6.7" for the D&D. An Etek-RT will just make it, but it will be a tight squeeze at 8.07". There is no way a Perm132 will fit inside the rails (8.75"), and I'm not wild about mounting the motor outside the cage.

I'm planning on mounting the controller and other electrical connections between the upper frame rails. The hollowed out gas tank will cover everything nicely, but may need some venting, or a fan to keep everything cool.

The prolific use of duct tape, although not permanent, would make Red Green proud.

Weighing in on a few things.

Today I loaded up El Gixxer along with all his pieces and put him on a freight scale. The whole bundle weighed in at 230 pounds, a little more than I was hoping for. One of us may need to go on a diet. OK we both could stand to lose a few.

I've been struggling to commit to an engine and battery combination. A Permanent Magnet motor and 40AmpHour batteries, will give me a very light bike, but will sacrifice durability and range. On the other hand, a 6.7" Series Wound motor with 60 AH batteries will give me the durability and range, but the extra weight means less acceleration.

The bottom line for weight is staying true to the project goals. The end result has to be a "bolt-in" kit. The average gearhead/propellerhead should be able take his Gixxer and yank the ICE motor, put in my battery frame and motor mount, then attach the components of his choice. If the project is significantly heavier or lighter than the original factory weight, the suspension components will need reworking ($$$).

So here's the weights as measured or estimated (*) assuming the heavier motor and batteries:

Rolling Frame 160
Brackets & Fasteners 32
Body Work 38
Battery & Motor 188
Missing Cosmetics 10*
Motor & Batt. Mount 20*
Chain & Sprockets 15*
Electronics 10*
Charger (external) 0*
Total 473 ( Factory Dry Weight: 456 lbs )

The PM motors are about 20 lbs lighter, so that would allow the kitted EV bike to use either motor without being too far off base.

Look Ma! No brakes!

It seems like I've done almost nothing since the last post. I did manage to get all the hydraulics off the bike over the last few days. Calipers, brake lines and master cylinders all gone. In each caliper I noticed one brake pad worn almost to the metal, and the other looked almost new.

I've also been attacking the various frame areas where black spray paint was applied (or mis-applied). After trying a few cleaning methods, the one I use the most is Orange GoJo hand cleaner. Rubbing gently with a rag or paper towel seems to dissolve the gunk and lightly abrades the aluminum, leaving a clean layer of metal.

It looks like the wheels were also painted a few times. Needless to say, none of the paint applications were well done. In fact, the wheels look like they were painted with a brush. It's hard to tell from the posted picture, but if you look close, there are some purple and white spots showing through on the edge of the rims.

Sometimes I think that all this attention to finish details is a waste. But I'm not a good enough mechanic to blaze through the disassembling and have everything committed to memory. Soo, I will continue to obsess and document.

Motor Decisons.

You probably can't tell by the photos, but I've removed dozens of bracket from the bike. I've also cleaned most of the chain lube gunk off. I've taken almost everything off the rolling chassis but the brakes. I've been avoiding the brakes, because that mean draining the brake fluid.

I've had some interesting discussions on motor choices lately, but I am still not committed. My head (& project goals) tells me to stick with the Etek-RT, but my heart says go with something a little bigger, like the Advanced DC / SepEx. I suppose we could make sure the bolt patterns for both kinds are on the motor mount, that way I can quit worrying about it. Makes more sense for a kit to accommodate several different motor choices. The extra holes will save weight too.

Adios Mr. Chain.

I couldn't stand looking at the chain or working around it. Unfortunately, I couldn't find a master link on the chain, and don't have a chain-breaker in my sparsely equipped toolbox. I ground the head off two of the pins, and then drove a screwdriver between adjacent plates. Crude, but effective.



I removed several brackets around the rear end, and stopped to take some pics. Hopefully, the pictures will prevent re-assembly brain glitches ("where the heck does this go"?). While taking the pictures, I noticed the lack of clearance between the face of the chain sprocket and the swing arm. Not a lot of room for a belt pulley.... hmm. I will be measuring this area very carefully.



I've been emailing questions to Phil at Supermax, to get some more details on their pulleys. The pulleys look awesome, but their website is pain to navigate, and no dimensional specs are listed anywhere. Fortunately, they respond to inquiries quickly and seem very nice.

Chain Lube Cleanup

I started preliminary cleanup, focusing on the engine bay, so I can get a feel for motor layout. Unfortunately, the caked on chain lube is everywhere. The more time I spend trying to get that junk off, the more I realize a chain drive is just not going to happen on my bike.

Harley's and other cruisers have used belts for a long time. Years ago, I had a Kawasaki GPz305 with a belt drive. Ever since that bike, I couldn't understand why anyone would want a chain. No lube, no adjustment, no mess and super quiet.

The downside is that a belt drive limits how small the size of the front sprocket, because the belt can't bend around a small sprocket (pulley) without seriously affecting life span of the belt. So this means a jackshaft will be needed to reduce the speed of the final drive, adding some costs and complexity to the project.

Donor bike comes home - 1991 Suzuki GSXR 750

I scanned Craig's List for a suitable bike, day after day, for almost two months. The goal was to get a decent rolling chassis, and have most of the bodywork in serviceable shape. I was really hoping to find an FZR600, since I used to have one and am familiar with them. Nothing even close to my price range came up within reasonable driving distance.



Finally, I put in my own ad, specifying a non-running, middle-weight sport bike, and listed the acceptable models. I had a few replies for stuff that wasn't going to work, and even heard from another guy looking for the same thing. I was getting very discouraged when a guy replied that had a GSXR and was close by. He didn't want to go any lower than my max price, but it was worth looking at.

After looking at the Gixxer, and visiting with seller I left with a good impression of both. The bike has a unique aluminum frame with lots of room for batteries and motor. It also has an adjustable suspension in the front and back. While I pondered the possibilities, I had a few hits on FZR's, but they turned out to be less than honest. I was convinced to move ahead with the Gixxer.

First Post to Blog

This blog was created to document the progress of a motorcycle conversion to an Electric Vehicle (EV).

The goals / limitations for this project:

- Less weight than the original published dry-weight: 458 lbs.
- Decent acceleration. If it's not faster than a scooter, please shoot me.
- Theoretical top speed of 50 mph at 64 Volts. (Reality will be closer to 45)
- No frame modifications, utilize existing mount points.
- Design mounting brackets and plates to created a "bolt-in" kit
- Project Cost: less than $5,000 (I hope)