Apollo 250 Dirt Bike Conversion

[skeetab5780]

Since I browse Craigslist daily for deals, I ran into this bike for $100 that someone wanted to get rid of. It was a complete dirt bike missing a few parts with bent handlebars and broken plastics. The motor looked brand spanking new and probably only had about 50 miles on it. (motor is on craigslist so hopefully I can break even when its sold)EDIT SOLD MOTOR FOR $80

Here is a picture of the bike new off google


Anywho these Apollo 250cc 4 stroke clunkers can be found on Amazon for $1350-$1700 shipped to your door. They seem to actually get decent reviews but take that with a grain of salt since whoever is leaving a Amazon review for this item probably never rode a real dirt bike in their life. With that being said, the bike is fairly heavy since everything is made of cheap Chinese steel. I spent a day removing all the stock parts and then another few days cutting and shaving all sorts of useless parts off the bike to lighten the load. I took the entire bottom of the frame off that used to hold the engine in place. It is now stripped down and I am ready to install the electrics.

[skeetab5780]

This is what the bike will be geared for with 20s lithium voltage im assuming 200lb total weight I haven't weighed it yet and have not finished welding motor mount yet, rest is done

slow but hopefully alot of torque

[skeetab5780]

Well I ended up going with the cheaper sine wave version. Looks like they have already sent me FedEx tracking! Hopefully this is enough juice...

[skeetab5780]

As it sits I have $165 into this


I spend $50 on renthal bars and grips and $15 on some #41 chain and links

Controller is ordered so that's another $235, motor I already owned but I have about $400 into it roughly

I need to buy a scale to weigh it, also need some metal stock to weld my motor mount...hopefully I can grab this stuff today if I have time!

[skeetab5780]

Mounting the #41 60t rear sprocket, I bought this over 2 years ago so I am using it out of spite

Clearance hole saw was a tad off, but I used a caliper measuring tool for the four holes


I cut down the rear sub frame already, believe it or not it was almost a foot longer than it is now, used a few handlebar ends to cap the square tubing

Not sure if this motor is up to the task but it will be really easy to find out, SO WE WILL!


I will have to make a battery gas tank to meet the seat height afterwards

[skeetab5780]

Postby nutspecial »
Awesome! Wow, you just can't go wrong with a full rolling chassis for 150$. Bicycle brakes, OR a wheel, Or bars and seat are like 150$, EACH lol. Does she weigh about 150lbs before electric?


Thanks for the input, I really don't know either. I'm pretty sure you just want the best balance of volts and amps to get to target wattage, while maintaining a usable reduction. The slower kv motors definitely like alot of volts, but I'm not sure about the >60kv LR types. I'd think you'll be fine with 6-8kw and 40mph. On my bike I just notice the motor starts getting warm in the summer when I'm burning amps but going slow. Never measured the temp, but guessing I back off around 150-170F. It really depends on how you wanna ride- If you're not too hard on it with high amps and low speed, I think the bht would get you moving to 60mph no problem.
I'm planning on gearing down from my current ~40mph topspeed on a heavier build though. For a dualsport maybe not, but for offroad I don't wanna sacrifice the low end performance (and climbing usability) of 0-30mph by gearing higher.


Postby skeetab5780 » Thu Jun 01, 2017 7:48 am

It was actually a complete dirt bike for $100 I got lucky, this is a generic bike you can buy on Amazon for $1500 (best part is I have the engine on craigslist for $150) so when I sell it this will be a wash

And I spend $50 on renthal bars and grips and a #41 chain

Controller is ordered so that's another $235, motor I already owned but I have about $400 into it roughly

I need to buy a scale to weigh it, also need some metal stock to weld my motor mount...hopefully I can grab this stuff today if I have time!

Postby nutspecial » Thu Jun 01, 2017 12:45 pm

Awesome! Alot of times, if you go to the metal supplier (who often also does at least some fabrication), you can ask a -worker- for some offfalls from the dumpster, for a little $. Worked for me the one time I tried, in fact they just gave 'em away. Also, some scrap yards will re-sell metal for pennies on the dollar. I got about 1000lbs of nice I beams, channel, and tube that way.

Ps, I just looked at that controller and it's nice! 300ph amps should be more than enough at 35mph gearing. I was running 200 and when I switched to 24s I turned it down to about 160 iirc- it was a little much. I can't see how many battery amps it supports though to compare with the other controllers. Guessing maybe up to 80a supported? Let us know if/when you find out.
In my understanding the battery amps are the power (combined with the battery voltage). Phase amps are how high of an amperage pulse the controller gives the motor FROM that initial wattage.

///btw, if the bht isn't enough, what do you think of this motor? http://eastgem.net/d7500.html Looks like it weighs close to 15 lbs, but it does have a faster wind. Would have to hit it with a 24fet (120-140a) to approach 10kw (controller side).


Postby skeetab5780 » Thu Jun 01, 2017 2:58 pm
Hmmm I've never seen this motor before even though I own the d3000w model, they are tiny... This 7500w motor looks pretty nice! Its similar to the Golden Motor 3kw weight but rated at twice the torque and more rpm's!!!

I may have to buy this if the BHT is not enough!


Thanks for the tip that is a good idea, my brother is a welder but he lives like an hour from me. His work may have a pile of scrap that's perfect!

Should be about 120a constant 300a peak, I started a thread for this over in the non ebike section.

[nutnspecial]

I just found it lol- thanks for moving my pertinent info over. Very nice job so far and I understand the temptation of that 7.5kw denzel. (Btw I see they also have a 14 or 15 tooth FW front sprocket for it, which I assume should hold up to their 7.5/10kw rating.) But yeah IDT 20s and 120a is too much for the BHT and will be dam knarly geared for 35mph!!!

Looks like you're thinking of mounting on the frame instead of the swingarm? I guess if it's pretty close to the old gasser motor output shaft that is totally the Ideal place.
-Jay

[skeetab5780]

Ya those freewheels caught my eye also, I doubt they will hold up to the power rating. I imagine they would be way more popular here if they did.

And yes this motor is so small I plan to tuck it as close to OEM output shaft as possible, also I am welding to the rear motor mounts.

In a perfect world I would rather build a lighter frame around this motor that I know is capable before I bought that 7500w denzel motor just to push more weight because of simplicity. We will see what the first test ride brings and see if it will be viable to continue.

[skeetab5780]

Little more progress on the bike, just ended up going to Home Depot and getting a 4' piece of metal stock so I could get this motor mounted. It worked out as easy as I planned it to be...as for my welding skills be nice, this harbor freight 80a dc stick welder can barely start an arc with 5/64" rods but I got it done!

Sanded and filed both motor mounts so they were at perfect 90degrees from the rear sprocket

Got the stock cut to size and clamped for welding

My beautiful welds


Motor was then clamped for a final chain mockup and then I was able to finish the bottom motor mount

Getting ready to do bottom mount

This thing was really hard to flip upside down alone, but I did it

Getting bottom bracket clamed for welding

Tacked in on both sides then did the same on the above side

Sharpied the motor mount holes, then tacked top of bottom bracket

Drilled them out fairly quickly and mounted the motor with excitement


I didn't notice until I posted these pictures but this weld on the top right is not too good, I will have to put more into it soon

Not sure if this chain will be strong enough i'm worried the links are a little thin, but threw it on and tightened the rear wheel


Who knows how it will work, controller should be in soon



Thanks for watching!

[macribs]

Great find, you can't go wrong with this. If the BHT feels lazy golden motor china got 10 kw, 15 kw and 25 kw mid motors. All of them below 500$ iirc.

[skeetab5780]

Those golden motors scare me, there are about four or five guys doing builds with the 3kw version and none of them seem to be happy with the end results. Luke says they are good only up to thier rated power then turn into heaters fairly quick after and take forever to cool. I passed up a really good deal on the 3kw version last week because of this knowledge. From what i read the Bht can put out more torque and weighs less that the hpm3000b by a few pounds.

With that being said the Bht motor does look awfully small mounted to this 250 dirt bike frame, but once i get it powered i will be able to compare it to the Golden motor builds.

Macribs did you see the d7500 motor? I would rather attempt that before a 5kw gm motor, and it has a splined motor output shaft which is easy for changing ratios

[macribs]

Fcuk isn't that the case more often then not? You get what you paid for? Been looking around for a powerful mid drive and had high hopes for the Golden motors, as they have water cooling as an option too. If their water cooling is more show then go, well I guess there is one more manufacturer that ends up on the no shop list.

That d7500 might be nice. Might still be a tad to light on the output department?

There is an urban legend growing about a clone mid drive motor capable of 40-50 kw peak. The more I think about it the more that clone motor appears to be the one of the few options for powerful mid drive build. Maybe we will see a new version a lighter and less powerful version creeping in around the 700$ mark yet with 20-25 kw peak power?

[skeetab5780]

Fcuk isn't that the case more often then not? You get what you paid for? Been looking around for a powerful mid drive and had high hopes for the Golden motors, as they have water cooling as an option too. If their water cooling is more show then go, well I guess there is one more manufacturer that ends up on the no shop list.

That d7500 might be nice. Might still be a tad to light on the output department?

There is an urban legend growing about a clone mid drive motor capable of 40-50 kw peak. The more I think about it the more that clone motor appears to be the one of the few options for powerful mid drive build. Maybe we will see a new version a lighter and less powerful version creeping in around the 700$ mark yet with 20-25 kw peak power?

Well to be fair people are putting 10kw thru the Bht rated at 1kw, so who knows if this d7500 can take 15kw or even 20kw?

Since I have two of the d3000w motors I would have to guess they aren't under rated. The d3000w seems like it can handle about 3500w-5000w max by its weight and size.

watching the d7500w run on the website from the Kelly controllers does make me want to give it a try tho.

[Overclocker]

definitely following this build!

a friend just recently ordered a big quanshun for mid-drive motorcycle conversion. we'll see how it goes...

[skeetab5780]

Ok this controller is freaking huge! Phase wires are four times the motor wires... Lets see if we can get a working combination going with a test battery.

[nutnspecial]

Wow I can't wait to see how that controller does. They look WAY better than a 200$ 18 fet infineon I've used. The ONLY downside for me would be it doesn't look like they support a 3spd switch? Everthing else (including kitch sink) looks supported/native though.
The only issue with the bht for this build (from my experience) is if 35mph will be geared too fast for the weight. But basically I play with 100-150lbs less on my build, running 6-7kw up to 40mph and bht only gets warm when I really beat it down low in the rpms alot, and only in hot weather. I think it'll be a r e a l l y fun ride, and easilly upgradable.

If I can sort out what else I want from eastgem I'll be ordering their 7.5kw before long for my steel frame build- I'm almost positive the few extra lbs of steel and copper will be worth it. Busy right now fixing main ride tho- my customized freehub broke (the outer wheel bearing race). Pita pita. Skee did you have any hiccups in dealing with eastgem for the 3kw motor(s)? Did you deal w/ Igor or Alex?

[skeetab5780]

So I was planning on welding the controller to the underside of the gas tank area above the motor for air cooling, but I found that it fit just perfectly between the seat stay and with the mud guard in place it was protected nicely

It stays in place without fastening it...had to move it back a tad so the seat could clip on



Found the right spot and zip tied it in place for now

Started working on all the wiring throttle and halls first

Soldered everything I could except for the 3 phases and 3 halls

Threw some plastic insulators in place to isolate the conductors from possibly hitting the frame

A piece over the top

Now the fun begins! Trying to find the correct hall combo

Didn't take long to get it spinning backwards, used the picture chart to reverse the direction like I did on my last build and it worked like a charm. Used some 4awg 3 port insulated lugs for the phases and then some #2awg butt splices for the power wires

Taped these up and heat shrunk them afterwards


This is the first time I've used wires this size on a ebike...

Heat gun to the rescue

Tucked the two phases away from one another just incase

laid the bike on the ground and quickly fixed the motor mount weld before test riding

Quickly threw a mounting setup together so I could use my LR genesis battery to test the bike

Picture all wired up with the controller lit up!

With the seat on you cant even see the batteries(the actual battery will be about twice this size)

After the first test ride I noticed that the chainline was a tad bit off the factory chain guards and rollers original paths. I ended up having to remove everything and make a new chain guard(improvising!)

Also had to tighten the rear wheel again after the chain stretched a bit

another random shot

Here you can see the quick fix where I tek screwed the chain slide where it needed to be

Picture after the first rip around the parking lot

This BHT motor and this sine wave controller are so quiet together its not even funny. Its noticeably quieter than my other bike by far. But I am haunted with the memory of last time I used this motor with the wrong hall combo. I hope its the right combo setting because it starts good from a standstill but if you crack the throttle too fast it seems to want to stall/cog out.

Otherwise it gets up to speed and rips, this is only with a 18s 12ah pack, the battery for this will be 20s eventually for more top end

[Overclocker]

oh wow i never thought the "little" bht could power a full size gasser frame. how are the temps?

[matt912836]

Video please! this is exactly the type of conversion im dying to do myself one day

[skeetab5780]

Since I do not have a battery for this yet I will count the cost of the LR genesis battery in this build so people can judge this thing
Dirt bike $100
Handlebars $30
Throttle $8
Dremmel tool blades and metal stock $22
Grips $10
Chain and sprockets $15
Controller and shipping $235
Connection lugs and random junk $15
Motor even though I already had it $400
LR Genesis battery pack 18s 12ah $220

Total actual cost $1055

Total out of pocket cost (since motor and battery were already owned) $435
EDIT SOLD THE 250CC MOTOR FOR $80 so bike cost is only $20 now

[parabellum]

. I took the entire bottom of the frame off that used to hold the engine in place. It is now stripped down and I am ready to install the electrics.

I do not know your plans for this bottom frame, but bottom frame AND the motor itself is a structural part of old Honda XL/NX chassis and all those post Honda Chinese knock off’s, after they bought the patents. I personally broke 2 XL's chassis with just not well tightened bolts on some of the motor mounts.
Be careful!
Nice project!!!

[skeetab5780]

Ya I am keeping an eye on the weak spot, thanks for the heads up. I doubt this thing will be getting much air off jumps, but you never know!

[skeetab5780]

What do you guys think of this idea. I want to put the front wheel on the back of the bike to lighten it and increase speed and rebuild the front end with 21" moto rim 20mm hub downhill bike components a triple crown 1-1/8" fork.

Would kill two birds with one stone sort of

[skeetab5780]

Wow I can't wait to see how that controller does. They look WAY better than a 200$ 18 fet infineon I've used. The ONLY downside for me would be it doesn't look like they support a 3spd switch? Everthing else (including kitch sink) looks supported/native though.
The only issue with the bht for this build (from my experience) is if 35mph will be geared too fast for the weight. But basically I play with 100-150lbs less on my build, running 6-7kw up to 40mph and bht only gets warm when I really beat it down low in the rpms alot, and only in hot weather. I think it'll be a r e a l l y fun ride, and easilly upgradable.

If I can sort out what else I want from eastgem I'll be ordering their 7.5kw before long for my steel frame build- I'm almost positive the few extra lbs of steel and copper will be worth it. Busy right now fixing main ride tho- my customized freehub broke (the outer wheel bearing race). Pita pita. Skee did you have any hiccups in dealing with eastgem for the 3kw motor(s)? Did you deal w/ Igor or Alex?

Ya for the price i think i may be trying the motor also, and I dealt with alex and they were pretty responsive and nice. Just long shipping on that second motor I bought.

[nutnspecial]

I told them over chat I was interested in the 7.5kw and some other stuff, specifically a moto seat for their older steel frames but never heard back via email. They prob forgot/overlooked it. I'll give it another go then.

put the front wheel on the back of the bike to lighten it and increase speed and rebuild the front end with 21" moto rim 20mm hub downhill bike components a triple crown 1-1/8" fork.

If axles, spacing, & headtube etc allow, it would still a large endeavor in time/money to save a few lbs. (<ten lbs?). I'd keep playin with it stock and get that controller running full tilt. That 12ah battery must be sagging pretty good too? Then I'd go bigger with the motor if you still want, trying to keep the rest of it as 'stock' as possible for cost/simplicity/balance.

That makes sense the bottom subframe was somewhat structural. I guess mainly for the headtube? Maybe adding some back or fabbing something under there for a decent sized battery would be good.