TaoTao Db17 LR Small Block build

[skeetab5780]

Here is a minimalistic build with the TaoTao Db17 dirt bike frame and a tiny LR small block motor that is supposed to be fairly capable for how small it is...we will find out soon!



This frame is left over from the Denzel 4-spd drive project and is fairly light with the vintage downhill forks and 17" Voloci DOT rated Stainless wheel set. I am going to see if I can get the total build weight to be even lighter than my 72v Death Voloci

Here are a few pics of the frame build from the Denzel thread to get up to speed

 

[skeetab5780]

So I used this extra piece of steel I had kicking around to make the bracket to mount the LR small block motor, it took like 2 hours since all I used was a hack saw, a file and a small grinder...It was a sweaty process but made for a really simple mounting solution.


In the pictures you see a Kelly controller but it is no good straight from the factory so I will not be purchasing another one unless they replace this one. For now I will be using a 72v 45a sine wave controller with a VM960 color display

I put this massive sprocket on the rear because I wanted this bike to have lots of torque and I already own a 72v death voloci so speed is not the requirement here

 

[skeetab5780]

Got this thing out for a ride today it accelerates silly fast! Top speed of 34 mph but I could not even stay there long due to no rear brakes and feeling sketchy with no foot pegs or safety gear...

A few pics of the awesomeness...this motor is tiny and packs a punch!

Shot of the bike next to the 1983 RM80N




Here you can see the plastic I tucked between my temp battery mount and motor falling out

 

[nicobie]

I bet you have trouble keeping the front wheel on the ground!

 

[skeetab5780]

 

[skeetab5780]

I bet you have trouble keeping the front wheel on the ground!

Yes this bike is a torque monster! there is a slight lag delay with this controller and throttle setup that scared me in the trail behind my house, I thought the throttle was stuck on the hand grip it held open a bit then I noticed it kept doing it. Will take some getting used to since I do not think you can program this controller

 

[A-DamW]

That chain noise under acceleration sounds like it is in sync with the full rotation of the chain itself.
Maybe check that the chain doesn't have any bent/worn/roughed up links.
Are you running a master link? it could be that under acceleration something flexes just enough to chafe.
Sounds like the chain itself to me.

 

[skeetab5780]

That chain noise under acceleration sounds like it is in sync with the full rotation of the chain itself.
Maybe check that the chain doesn't have any bent/worn/roughed up links.
Are you running a master link? it could be that under acceleration something flexes just enough to chafe.
Sounds like the chain itself to me.

Yes I am running a master link and the chain is too large I think it is a #40 chain same pitch as a 415H but alot wider

I have the correct chain to put on today it came in the mail! Hopefully this solves the issue you may be right!

 

[skeetab5780]

What a shame my new 415H chain is 120 links and I need 123 links with this huge sprocket lol...now I am on the hunt for a 130 link before I need to buy another short one and another master link

Well I found a #41 chain from Tractor Supply today lets see if that works until my new 415 chain comes in

Now I have spent $100 on chain for this build because I did not measure it before ordering!
EDIT: The Tractor supply #41 chain worked for now! My Oury grips came in the mail and I think I am going to change the handlebars out they are from a chinese dirt bike and they are slightly bent on the left side

 

[skeetab5780]

Another quick video of the first day ride with GoPro. I have ordered new handlebars and grips and a 415 chain which all should be installed by next week

 

[skeetab5780]

So I put the new handlebars/grips and 415 chain on the bike

But I think the handlebars have too much of a rise for this bike. It feels a bit too cruiser-ish feeling now like all the weight is on the rear...what do you think?

 

[skeetab5780]

 

[skeetab5780]

 

[skeetab5780]

 

[skeetab5780]

Winter always slightly hinders my project completion percentages, so this bike still has no rear brakes and a temporary battery...But it is loads of fun when my daughter A gets on this bike since she is so lightweight it takes off like a rocket compared to her heavier counterpart(Ebay Dirt Bike)

Here is a YT short of her finally hitting full throttle in speed 3, as I egg her on and pass her one handed while recording on my Kuberg Freerider. She did put it in speed 4 once in the ball field but immediately turned it back down since the throttle is very touchy in speed 4

 

[skeetab5780]

Here is a nice winter ride with the Db17 LR small block and the Death Voloci a few times in the video I say 1,2,3 and we go full throttle and race. The LR small block is faster off the line every time but i quickly get up to speed and pass her on the Death Voloci. Bear in mind that she weighs 100lbs and I am well more than double that! Still lots of fun riding around on the fast bikes!

 

[skeetab5780]

Quick video of me fixing the rear brake system i added to the Db17 LR small block ebike!

Made the mounting bracket and the two axle dropouts out of angle iron i had kicking around the house, used the Ebay brake caliper i originally bought for the Ebay dirt bike on this bike...it is super overkill but has amazing stopping force!

 

[skeetab5780]

Put new 20s4p 21700 packs in both bikes, quick short of us riding them to her school!

Then she goes for a ride yesterday and the chain fell off! Its always something!

 

[skeetab5780]

This bike is freaking fast! I just got a new Talaria Sting R and her bike is keeping up with me at 44mph! (her battery is 20s4p 21700 20ah)
I just put new front brakes on the bike since she wore out here first set of vintage Julie hydraulics, she wore out the rear brakes 6 months ago and i upgraded those to actual hydraulic dirt bike calipers off a 125cc

and now she needs new headset bearings. Since we are using a Cane creek 10 ZS44 headset for a dirt bike frame it is a tad bit loose, i shim it with some sheet metal but it seems to wear the bearings quicker than normal. i added a wrap of aluminum tape to get it even snugger but now bearings have failed



The throat of the headset cups were a tad smaller in diameter than I would have preferred, hopefully the headset holds up with the shims in place



also the rear sprocket came of yesterday when we were riding hard on the train tracks, three of the six bolts snapped off leaving us to limp home at 5mph with 2 bolts left holding it on wobbling back to the house(one bolt broke months ago) we made it home but the second she pulled into the yard the chain fell off!

So after the rain stopped i took the entire rear wheel off Dremel cut the snapped allen bolts out of the 6 bolt ISO of the hub and reversed the wheel(these wheels have 6bolt ISO on both sides) I put the mangled stripped pattern on the disc brake side since it doesnt see as much torque or action compared to this huge stand off sprocket. Then i started re-mounting everything a tad differently than i did before

prior i was using 6x 1/4" rod couplers to stand the sprocket off the hub to get closer to the motor sprockets chain line, but that was putting too much stress on the 6-bolt ISO. So i cut the stand off distance in half so i can use much shorter bolts, and then i had to take the front sprocket off the LR small block and turn it inside out so the teeth are closer to the motor to improve the chain line and make the motor drive spin freely. Doing this made the chain almost fall between the frame and the swingarm since its now much closer in, so to fix this i tek screwed a chain slide that overhangs the swingarm on the inside so the chain cannot fall in between.

This is a picture of the old bad mounting

 

[skeetab5780]

Hmm now after all this reworking of the system, she goes to ride the bike today and the chain broke...this is a #41 chain rated at over 500lb workload. Not sure what happened since i was not there wondering what went wrong

 

[skeetab5780]

Actually the chain is a 415 chain and only the master link broke, I found that the chain was a tad too close to the frame on the bottom of the chain line and it was rubbing against the weld for the old stock kickstand right behind the foot peg area...i took the Dremmel tool to the mount and cut it off and grinded the weld flat, then moved the LR small block sprocket out like 1/8"

i had one extra 415 master link and then put the bike back together again and we went out riding! So far so good she was able to go full speed and rip around like usual!

Here you can see how i had to reverse the LR small block sprocket so the teeth are closest to the motor to improve the new chain line

Here you can see the new stand offs from the 6 bolt ISO are much shorter and will have alot less stress on them hopefully increasing the lifespan

Here you can see the new makeshift kickstand i made for the bike, she was getting tired of always finding a tree to rest the bike on... and you can see a small plastic guide that i tek screwed on top of the swingarm so the chain will not fall between the frame and the swingarm

 

[skeetab5780]

So the headset bearings on the Cane Creek headset needed replacing and at the same time I decided to change out the 45a Ebay controller to a Kelly KBX72121X since the Ebay controller had this slight throttle delay which I think is quite dangerous. I had trouble finding a correct hall phase combination I kept blue to blue and crossed green and yellow on the halls and phases which is pretty common...but for some reason the motor and controller pairing is very loud and seems like the timing is off a bit

I also needed to weld a bracket on the rear swingarm for a brake mount and I did it so rushed and half assed it only lasted about an hour until it slightly bent and now needs fixing again!

The bike now flies! top speed is actually 48mph

 

[skeetab5780]

Here is a video of the second day of riding the bike with the new Kelly controller with my daughter, the controller has a green light with no faults after two days but still seems like we are running a false positive combo...i tried the phase reversal chart we use here on the forums and it doesn't help at all

since my daughter doesn't read this forum I can say it does not really matter too much since I just ordered her a Talaria MX3 for her birthday! So she only needs to ride this bike for another few weeks

 

[skeetab5780]

Short of A riding down the road in CT

 

[skeetab5780]

Well I will admit when I mess up and this is one of those times...I could not find the correct phase wiring combo for the Kelly to the LR small block and after three days we have officially smoked the motor...Got extremely hot and let out the smell we all know...

I knew the wiring combo was wrong and continued to run it since I couldn't find the correct combo i tried for a few hours

So now we are out a $350 motor and I am not buying a new one since i just ordered her a Talaria...so we must now wait for the new bike to arrive