Don's lightweight conversions

[Philip]

Just wanted to share that @DonCox builds such fun electric conversions!

Last week I got to ride his electric 2005 CRF250R conversion. I am not the guy who enjoys joy-riding or even test-riding other people's bikes. I am cautious, and if something doesn't feel quite right, I slow down and bring the bike back home safely. But this one was different! I got hooked on it immediately and did not want to get off!

The bike felt so right!!! I own a 2005 CRF250R myself, a gasoline one, and 10 years ago, I used to race it every weekend. I jumped onto Don't bike, and I immediately felt invincible! Everything felt amazing. It was so light, so flickable! Compared to my Stark, it felt like it was half the weight, like a Supermini. I swear, the front end felt like it could never slip. And the steering was so subliminal that I was sure I did not even need to hold the handlebars, just lean the bike into the turn with my knees, twist the throttle, and wheelie out of any hairpin or rut!

Unfortunately, the asphalt in front of Don's house has no ruts. The front tire hooked up exactly as I expected, but the rear slid a little. No damage to the bike, just a small hole in my sneaker! LOL!

Enjoy!

 

[VINSANITY]

I have the same opinion as you Phillip. I really like the Stark but to me it feels heavy (or not nimble?) - I built a conversion using the Don Cox formula and I seriously think it is the best bike I have ever had. It just works.

I had an Alta and really enjoyed it but it was heavy and it wore me out. To me the Stark feels similar.

I wish I could just buy a bike that is full size, weighs about 230-240 pounds and has a quick swap battery. I am not a pro but I ride pretty aggressive and the conversion is more than enough power for MX, trails, street - basically all types of riding.

Hopefully there are some companies that pay attention to the forum and see that there is a major opportunity for this type of bike. Looking back at history when the Japanese brands went into motocross they weren’t good at first but they worked riders and builders and in a relatively short period of time dominated the market. A manufacturer should really get one of these conversions and use it as a template.

 

[OpaTsupa]

Give us some numbers for context:
Weight, power, price to build, price to buy, range etc.

Forgive the dumb question, but why not use the entire space inside the frame?

 

[VINSANITY]

Numbers based on my build using a 2005 RMZ250 Chassis:

Build Cost: $6,000
QS138 motor - $700
FarDriver 96V controller - $750
Amorge 96V x 45 amp/hr battery - $2,500
Street legal wiring and display - $300
Misc parts, motor mounts etc. - $250
Donor Bike (this can vary a lot) - $1,500

NOTE: I had additional cost like plastics, suspension work, tires etc that were my preference but not essential.

A person has to have good bike mechanical skills, basic understanding of wiring and needs to be able to tune the controller. I think around 20-40 hours to build a bike, but in my case a lot of the time was spent getting the donor bike rebuilt. Also welding usually needed to make a battery mount system.

Peak Power
33 KW (96volts x 350 amps) - 44HP
Range Off Road
Aggressive Trail Riding Sandy - 20 to 25 miles
Range Street
30 to 50 mph - 25 to 30 miles

Regarding the battery not filling the frame, most people try to get the biggest size battery in the frame without modifying the frame. So you get many different shapes and sizes of batteries depending on the frame.

Once you build one conversion bike you then have the knowledge to build again, but you will be much more efficient on your next attempts. Also, once you have your build done you can then upgrade in future with new controller for example when improved products come out.

 

[Theo]

why not use the entire space inside the frame?

I've never converted any bike but I think I know the answer: if it's a non swappable battery, it has to have a shape that lets you install it into the frame when you build the bike; if it' a swappable battery, it should also be easy to install onto and uninstall from the bike.

Don't you guys have any problems being allowed into tracks? I've watched a video of some guys who tried entring a local track here in Italy where I sometimes ride and one of them had a Varg and the other had an Ultra Bee or maybe it was a Light Bee. The marshalls initially didn't allow the Surron in because they didn't know it and thought it was dangerous and IIRC they eventually let them ride.

@VINSANITY: that Suzuki looks quite neat and cool! The fact that you can upgrade parts surely is and advantage.

 

[VINSANITY]

A bit of a downer that tracks may or may not allow e-bikes. Rules are a little looser in US but my closest track no longer allows any e-bikes, they claim there insurance does not cover that risk. I know some people who are close to the situation and apparently they have had complaints that ICE bike riders can’t hear when e-bikes pass them and there have been incidents, so that is probably the reason they banned them.

Recall when snowboards first came out they were banned at many ski hills until they reached critical mass, I think same thing will happen here.

About the Suzuki, it has 2023 fork, shock and brakes. The frame is old is really same / similar geometry as modern bikes. James Stewart went fast on it so should be good enough for me.

 

[DaveAusNor]

It was so light, so flickable! Compared to my Stark, it felt like it was half the weight

Awesome! that sounds like a lot of fun. I guess this could be due to the smaller battery a little further back on the bike. Is the radiator and fins purely for structural integrity? Could cut a little more weight there is seems.