View Full Version : Ninja Turtle Spin Cycle

06-20-2015, 04:20 PM
Purchased plans yesterday and am purchasing a couple of kids bikes from Goodwill today. Purchased some 8inch castors w/ balloon wheels last week from HF. Yesterday purchased metal as well.
Question is about the seat. This is going to be for my 6 year old grandson thus planning on an adjustable seat but wonder about the COG. The plans mention about weight distribution but??
Any thoughts.
The lager castors should slow down the amount of spin??

06-20-2015, 05:34 PM
Not sure what cog stands for. The more you angle the castors forward the straighter it will track. I changed my front wheel from 20 to 16 and now it spins more so when I want. I started with them angled almost a little back I would touch the pedal and spin. Dropped front angle to the 3 to 5 degree mark and it was more controlled but still unpredictable. When I decreased the front wheel size I was able to ride it all around the neighborhood and a 1.5 mile loop at the park. I did have to drift down hills. Other option would be to create a lever lock or stop for on castor. Then he could pull the lever and spin out but otherwise ride like a normal bike

06-20-2015, 06:16 PM
COG= Center of Gravity- Which on Trike you want to keep as low to ground as possible to avoid tipping over when riding wild or going around corners.

06-20-2015, 07:58 PM
just got back from GOODWILL and scored big time on a kids bike w/ 20" wheels.
How is that a great bargain?? Walking across the parking lot to the door I see a $10 bill laying on the ground and a $5 a few feet away. The bike cost me $12.99 + tax.
On the way back home I stopped in a friends house (he restores old cars and trucks) and he gave me a steering colum w/ gear box for my T bucket recumbent. Now I can put longer arms on the steering arms and get a tighter turning radius. Right now it is aprox 15-20 ft.
Then he gave me a dc motor for a gate closer that runs on 12-24 volt. 7.7 amps and .-7 to .14hp. 1760 - 4200 rpm. Not much but thjinking all I need to to assist going up slight inclines.

06-20-2015, 08:04 PM
found a weight to hp calculator/ using 300 pounds and .14hp I can do a quarter mile in 75 seconds at 18 mph.
This may be the ticket as I really don't want to go faster than 15 mph and do some pedaling.
Also learned about NRP pannels I could use for my T-bucket body.

Radical Brad
06-21-2015, 08:27 AM
You will want the top of the seat below the height of the front axle.
Go to a smaller front wheel if need be.


06-21-2015, 09:45 AM
Maybe Brad got this backwards??
You will want the top of the seat below the height of the front axle.
Go to a smaller front wheel if need be.
the smaller the front wheel the closer to the ground the rear seat is.
A 20" wheel the seat can be less than 10" from the ground while the 16" wheel the seat can be 8" from the ground.
Yes the seat would be lower in respect to the ground but two issues come into play. Finding 16" tires & tubes and ground scrape over bumps.
I am contemplating maybe, and a big maybe, a tie rod from the front wheel to one of the rear casters to make spinning easier. Even had the idea of locking the front wheel and have the handle bars connected to one caster via a tie rod. Issue is routing of the tie rod unless a cable is used??
cutting frame members tomorrow and hacking the bike I purchased.

06-21-2015, 10:29 AM
Mr Idaho I am having a hard time following your plan. I would feel the tie rod would limit your movement. However to do your rear steering you could use a kids kick scooter chopped and slightly modified but that would mean changing the wheels from the ones you listed. Maybe I have not created the right mental picture of the project. If a tie rod goes from front wheel to castor Don't you only have 90 degrees of motion max. For this you want at least 180 and in all honesty a little more. The electrifying would be pretty wild. I am really interested to see this play out. I am gonna have to look at your original plan. The other concern is the 20 inch wheel for a 6 year old makes me wonder where the pedals will be or is it purely electric.even going to a smaller crank with my 16 inch wheel my 9 year old daughter has to lay flat and stretch just to pedal slowly. You have a lot more experience building bikes than I have so I am sure your bike makes a lot more sense than my feeble mind is understanding.

06-22-2015, 09:10 AM
This thread got kinda mixed up. The electric motor is for my T bucket project, not the spin cycle.
My thinking on the spin cycle is really simple (yea right) in principal. One of the rear casters is controlled by a steering set up utilizing a handle bar and tie rods. the front wheel could be locked straight and the handle bars connected to the caster provides steering. After contemplating this idea I think it may want to tip over but??

06-22-2015, 09:10 AM
Oh on the leg stretch, have the seat adjustable.

06-22-2015, 09:37 AM
Oh on the leg stretch, have the seat adjustable.

Suggest you measure little Johnie's inner leg before he rides it and develops a split personality ..... :juggle2: :wheelchair:.............:oops:


06-22-2015, 11:00 AM
I think if you went with your original plan on the first post about this. Adjustable seat would work. Taking the aurora style with castors. Pedals on the rider side instead of the front. If you want his legs to reach accross the wheel I would consider a 12" wheel. I was thinking how to lock a wheel that otherwise is a free spinning castor. Since they hang out the back you could have a lever to some sort of a u bracket that would surround the castor mount. As long as 2 wheels are oriented same 3rd will follow.

06-22-2015, 12:34 PM
Here is a really rough sketch of my idea. Just contemplating how this would work out??

http://i992.photobucket.com/albums/af44/MrDEB/first%20sketch_zpssgj8p38v.png (http://s992.photobucket.com/user/MrDEB/media/first%20sketch_zpssgj8p38v.png.html)

06-23-2015, 07:26 PM
Well I managed to get the donor bike all in pieces and front forks built using 3/4 box. Got to looking at the forks and asked myself if it is doable to put the crank set between the rider and front wheel instead of in front of the front wheel. Thinking that this may solve the short legged rider issue but have the seat adjustable. Looking over a few pics of FWD recumbents but can't find very many. The U2CAN hand cycle has some interesting characteristics.
Thinking out of the box but placing the cranks (BB) on top of the steering head tube.

06-24-2015, 02:42 AM
Well I managed to get the donor bike all in pieces and front forks built using 3/4 box. Got to looking at the forks and asked myself if it is doable to put the crank set between the rider and front wheel instead of in front of the front wheel. Thinking that this may solve the short legged rider issue but have the seat adjustable.

try looking up F'lowroller by robert horn :-


It is the most famous of that style.

06-24-2015, 10:40 AM
Several good ideas there, THANKS

06-24-2015, 06:57 PM
got forks and BB assembled but going to attach the BB w/cranks after I get the frame assembled. Pretty much got the frame welded but it got too hot in shop plus my new seats for T bucket came in so will finish welding and configuring frame in the morning. I almost assembled with the head tube at 90 degrees instead of 55-60 degrees. funny the plans have no mention of head tube angle.
Will take pics in morning.
Oh I almost forgot, the BB is hopefully to be just behind the front wheel and slightly lower? or above? the axle center. I need to get frame and head tube assembled as one first.
Am figuring for BB from axle center at 14". The rim Radius= 10" + 2" for tire and 1" for error clearance.

06-24-2015, 07:04 PM
I wonder if you could get some inspiration from the wrff it trike. I know it is not quite what you are talking about but short wheel base pedal powered thing. Bet if you made it more sit down it would be really cool. Maybe a steering wheel and use pneumatic wheels minus castor mounts. Just trying to give ideas

06-24-2015, 10:44 PM
what is the wrff it trike?
I searched but ??

06-25-2015, 12:05 AM
It is a weird stand up bike with 2 wheels in front that was created by a band in the 90s. It is no longer for sale but I found one on the local craigslist but his son decided to keep it. I will try to find a link. Wrff was the radio station that I assume backed the guys. I found it in Google images and youtube videos when I was going to purchase it

06-25-2015, 12:17 AM
http://www.google.com/imgres?imgurl=https://i.ytimg.com/vi/zJP1_i6UFYs/mqdefault.jpg&imgrefurl=http://player.mashpedia.com/player.php?q%3DFfNUAonMzL8&h=180&w=320&tbnid=j1pd2MgnsWmqzM:&zoom=1&docid=30m79iXdNuZ2hM&itg=1&ei=gn-LVZCzGcKcgwTKn4GoDA&tbm=isch&client=ms-android-verizon&ved=0CCMQMygfMB84yAE http://www.google.com/imgres?imgurl=http://s3item.bookooinc.netdna-cdn.com/s400_478e23a5b013d54537eaea8127471.jpg&imgrefurl=http://www.bentrideronline.com/messageboard/showthread.php?t%3D117624&h=400&w=533&tbnid=XZEpTSLIztOZxM:&zoom=1&docid=iiRmxF84cOPCOM&ei=Xn-LVernHYa1ggTzzoqYCg&tbm=isch&client=ms-android-verizon&ved=0CCEQMygEMAQ

06-25-2015, 12:19 AM
There is the original in the second link and first has 2 model out to be little recumbent trikes

06-25-2015, 08:53 AM
cute little form of transportation. Thanks.

07-04-2015, 12:32 AM
well I started on this project and hopefully will have no issues with legs hitting the front wheel. Looks ok as I am mounting the BB/ CRANKS close and high to avoid.
Still like the idea of a tie rod connected to the front fork and one caster.http://i992.photobucket.com/albums/af44/MrDEB/new%20spin%20cycle_zpsw4mx4xwq.png (http://s992.photobucket.com/user/MrDEB/media/new%20spin%20cycle_zpsw4mx4xwq.png.html)

Radical Brad
07-04-2015, 10:31 AM
Once you tack weld it together, any issues will present themselves.
Best way to prototype... try it and see!


07-04-2015, 11:59 AM
that's where I am headed maybe tomorrow or Monday. Was hoping today but too much going on today, parade, picnic in the park then fireworks show tonight..
Looking at the setup it looks like it might work but going to tack weld first for sure then look at clearances etc. My grandson should get a trial fit but that's no going to happen. Hoping perhaps a neighbor has grand kids visiting about same size for a trial fit but not actually ride since it will only be tack welded.

07-18-2015, 01:37 PM
here are some pics of the Ninja spin cycle for my 6 year old grandson. the castor wheel is what this creature is going to ride on. Using larger wheels to lessen the spinning to wild as he is only 6 years old August 1st. Today we get a test fit before going further. Probably went to far already??
http://i992.photobucket.com/albums/af44/MrDEB/pic1_zpshk3ya6mm.jpg (http://s992.photobucket.com/user/MrDEB/media/pic1_zpshk3ya6mm.jpg.html) http://i992.photobucket.com/albums/af44/MrDEB/wheel_zps077tmm7m.jpg (http://s992.photobucket.com/user/MrDEB/media/wheel_zps077tmm7m.jpg.html)

07-18-2015, 10:36 PM
Some good old ape hanger handlebars and should be good . Like it so far you will have to keep us updated. Just remember that having the back wheels lean forward will help in keeping it straight and decrease the wild spinning

07-19-2015, 10:31 AM
Don't think I will keep this creation as the grandson wasn't real happy with it plus the sprocket could hit a leg.
thinking of starting over but having front wheel where it is stationary as in won't turn for steering but have a set of handle bars that control one castor as per leaux racing trike.
Or build him a delta style similar to a Meridian type trike.

07-19-2015, 11:10 PM
I wonder if you took the fork and attached it in line with the seat area, then on the back add a tie rod like in the streetfox and attach handles so you steer the casters directly together

07-20-2015, 12:06 AM
my though was to secure the front wheel so it won't turn, install another set of handle bar with tie rod to one castor. this would be behind the present handle bars as there is no room in front.
the seat area would need to be lengthen maybe?? so the BB could be just in front of the seat.
Will ponder this after I make a few sketches and measurements.
Even considering cutting the rear off and making a two wheel bike??

07-20-2015, 12:30 AM
here is what I am contemplating if I don't start all over on a two wheel bike
oups I have no provisions to pedal it,
http://i992.photobucket.com/albums/af44/MrDEB/trike%20revisions_zpsmfroiyjw.png (http://s992.photobucket.com/user/MrDEB/media/trike%20revisions_zpsmfroiyjw.png.html)

07-20-2015, 08:46 AM
http://s21.postimg.org/ti58uc8cj/20150720_082143.jpg (http://postimg.org/image/ti58uc8cj/)
This was the idea I had to solve the problem. Being that the rear wheels are 10 inches so roughly half the front wheel in my brain it works correctly. I though having basically reverse street fox steering would make it fun. Plus that way there are 2 handles. Also thought about your plan with a steering wheel versus the handle bars might make it look cool. Don't know if the thoughts are helpful but you got me thinking of ideas

07-20-2015, 02:38 PM
nice idea but only need one castor with steering rod. once the one castor is turned, hopefully the other castor will turn. The trike on youtube?? has a handle on one wheel only.
Going to do some pondering on ideas.