View Full Version : the rhino bike..

08-16-2009, 12:38 AM
I have begun to build a friction drive. The drive is actually the rear wheel of a scooter with a scooter motor and controller. I just started a new one so I thought I would take you along for the build.

First of all I have been assembling the parts while I wait for the rear wheel of the scooter to arrive. Since I have done this before I know exactly what I need and but I can't assemble it until the wheel arrives.

I have a 500 watt motor and controller with throttle waiting. I have two pieces of angle steel with a hole cut for the scooter axle. I have the battery trailer rebuilt for optimum performance.

I bought a yard sale bike today and rebuilt it. To rebuild it I had to almost build a bike from scratch. Here is the list..

The easiest fix... it had no kick stand..

The crank arms were too long. I had a shorter set from a kids 20" bike.

The seat was a laid back thing but it was too short. I welded an extension on it.

The front fork was loose but wouldn't tighten. It was all rusted in place. I used an angle grinder to cut it loose. Then I installed a 20" suspension fork with shackles to raise it two inches. I then had to mount the front brake to it with a special holder welded on.

I replaced the handlebars with a set I had laying around.

I cut and reassembled the chain. Then new chain ring was larger than the old one.

So here are some photos of it after it was fixed but before I touched up the paint. I wanted to show the repairs.


08-16-2009, 11:59 AM
While I await my wheel, I salvaged a couple of rails for the sides of the bike. They had been part of a PAT which I built last. The Rhino is no more than a pat turned upside down. I use a smaller wheel, but it is more or less the same drive system.

Once the wheel gets here, Tuesday, I will need to mount it to the rails, attach the motor which already has the mount attached, make a couple of end caps, add a hinge and spring along with a scissor hinge to keep it in line, then it will be ready to wire and ride. I have a couple of relays on the way to eliminate the need for a controller.

So look for more updates to this system coming sometime after Tuesday.

08-16-2009, 12:28 PM
Deacon, can you give us a picture of these rails? What exactly is their purpose, or are you just talking about the sides of the motor mount you'll be mounting on this bike? BTW, how do you find the time to garage sale, and build all of these electric bikes?:D

08-16-2009, 06:11 PM
Why I'm disabled. When I started with bicycles I was stumbling and my balance was almost completely gone. I have a brain tumor and a couple of heart attacks. I was pretty much waiting for the end.

I thought I would try a bike. I bought one at salvation army thrift store. I had not ridden a bike in almost fifty years. The brain tumor is squeezing my brain so the voids that control balance is being misshaped as far as I can tell. It's kind of like a tiny water level in there.

Anyway I took the bike home and got on it in my driveway. It was a 24" mountain bike. I promptly feel off it and skinned my kneed and banged the heck out of my shoulder. I donated that bike to goodwill. As the days went on I decided I would not give up so I bought a big huffy cruiser on craig's list.

I wasn't a lot of fun but I didn't fall off it anyway. The heart damaged caused the hills to beat me to death, but I got better and better at staying upright on it. My brain was finding new ways to control my balance.

I read somewhere on the net about a man who built an ebike with a starter motor. It said the motor just helped him with hills. Now that was just what I thought I needed. So I began experimenting and I just never stopped.

After a few tries with the ebikes I went to the china gasoline kit engines, then weed whackers and chain saws. From there I went back to ebikes. Mainly I stay with them now because they are unregulated. I also don't go far or have a need for speed so they suit my purpose.

Yes the side rails are just to hold the motor. They are just a foot of angle iron with a 3/8 hole drilled in them. I will bolt the axle to them then make and end cap for each end to make the full unit.

I have been thinking about the hinge mount that I usually do on the front of the motor frame. I attach it to the bike with a single 1/4 bolt. I have never had a problem with it but it does allow the motor to vibrate loose then twist. That is the reason I have to build a scissor hinge for one side of the motor.

I'm thinking I just might cut a piece of that box channel you can buy at the home depot just a hair shorter than the wheel frame is wide. then weld a couple of pieces of flat stock to the sides of the motor frame. I could then slip those on each side of the channel I welded to the bike and run a long bolt through all of it. It would allow the motor frame to ride on the bolt/pin but eliminate most of the side to side twist.http://i26.tinypic.com/bgadyf.jpg

that particular attachment method would also allow it to be attached to a mountain bike without losing the brakes on the rear wheel. Minimally intrusive except for the welding which would ruin the paint. that is a non issue with me but probably a big deal to a lot of people.

08-16-2009, 06:25 PM
This is where I am at the moment... Just have the rails ready. I can't do anything else till I get the wheel and motor together to take measurements.

The other side rail will have the motor mount inside it. I'll try to make some photos of it.

08-17-2009, 09:25 PM
I'm disabled also, and I still can't find that much time. I'm sorry to hear about your brain tumor. I had a stroke, and I thought that was horrible. I felt sorry for myself (which I hate to admit) the entire time I was relearning to speak. Well, I had to relearn to speak intelligibly.

Please keep us informed about this project. Some of us (me, for one) enjoy reading about your adventures. I've also been reading your "regular" blog, (http://deaconcomments.blogspot.com/) as well as your bike blog (http://frictiondrivebicycles.blogspot.com/). They are enjoyable reading, to me at least. I think you should link them in your sig here, like you do at motorbicycling.com.

08-17-2009, 11:10 PM
Thanks I knew one person was reading them.... So now I know who you are.... I have them linked except for the novel in progress. That is linked from the blog.

Sorry about the stroke by the way. I build all day long most everyday. I try to stay ahead of the symptoms. Oh now and then I feel sorry for myself but then I look at some of my friends and kinfolk. Some are worse off than me of course, and some who aren't are just plain strange lol.

By the by, I did some serious experiments with over powering e scooter motors today. I found that both my cheap 350 watt controller and my better quality 500 watt controller will accept a 36 watt power supply and really hum on it. The next rhino bike I'm working on should be a real gut wrench er since it is going to be 500 watts with a power supply to kick it up to 700 watts. I even have a bigger sprocket for the motor but I doubt that I will use it. I lack the courage to go much faster than the 350 on steroids that I created today.

I am going to have to switch trailers for the power pack since the one I'm using is a bit rough pulling. It's made from lawn mower wheels with no bearings. They have a metal wheel with bearings I'll probably use next time. I have one with scooter wheels I need to switch to for now.

08-18-2009, 06:44 AM
Oh now and then I feel sorry for myself but then I look at some of my friends and kinfolk. Some are worse off than me of course, and some who aren't are just plain strange lol.

Haha, I know what you mean on both counts! No matter what's wrong with you, there's nearly always someone who is much worse off, I've noticed. Also, probably every family has that one person that nobody would ever mention in public.:D

By the by, I did some serious experiments with over powering e scooter motors today.

DC electric motors handle being overvolted very well, and controllers handle an extra 12V just fine. I've seen instances of people running 72V through their 48V motors and stock controllers (scooters, not bikes), but adding two extra batteries isn't easy. That requires swapping mosfets and capacitors, etc in the controller. But I've never heard of one that couldn't handle an extra 12V indefinitely. Engineers overdesign, you know.;)

08-18-2009, 12:10 PM
Some of the forums have the newby like me taking the controller apart and checking for marking on the components. I just gave it a try. The first time I blew a fuse and thought I might have damaged the controller. I was pretty concerned about doing it again. Then I just gave it a shot with the most robust one I had. After that I tried the cheapo version and it worked as well. The main thing is that the fuses are rated for a 12v auto system. It's scary if you don't realize that. You think you are drawing 40 amps when in fact you are drawing a little over 20 amps the rating of the motor when it blows. That is even with a 40 amp fuse.

My main problem with that now is trailers. I built my best trailer to carry two sla batteries. I tested the over power system with a trailer make from lawn mower wheels. It won't fall apart but the wheels have to be a bit loose for it to move. It does not track as well as the one make with scooter front wheels. I expect that before my wheel comes today I will try to rebuild the bed on the scooter wheel trailer. Since the 24v runs slower I will probably keep the lawn mower wheel trailer for it. From that experiment I at least learned the value of a square trailer tongue. That is a good thing to know.

The next trailer I build will be built with a combination of things I have learned about them. One thing is the frame design using sqaure channel you can buy at the home depot and 3/8" all thread rod.


08-18-2009, 07:57 PM
Building this second Rhino bike is making me crazy. The wheel I need to complete it is supposed to be on a fed ex truck and out to delivery. Its 3pm and no wheel. I swear this is going to make me crazy, I have been doing make work to pass the time.

I switched trailers so the good trailer has the 36v battery pack. I make a come along for the trailer so I can roll it in and out off the bike. I pulled the motor from the DIY wheel that never worked quite right. I just need to get the wheel so I can bolt it together.

Oh well I guess this is going to build character.

08-19-2009, 12:09 AM

So, you really are an engineer, and just didn't want to tell us, huh? Speaking of building character, my grandfather used to always say, "If it doesn't kill you, it makes you stronger", to which I would always think, "Yeah, but what about the times when it successfully kills you?":)

08-19-2009, 01:06 AM
I think this might be the one to test my sanity as well as my character. I tried to break and shorten a #25 chain after an hour in a sweat shop environment I gave up and put in a master link.

I didn't take any pictures I was too busy trying to get something done before dark. I managed to get the motor frame built and set it on the bike for a test fit. I had to make an extension for the frame to bike mount. The laid back seat post is in the way. I will have it mounted by noon tomorrow if it harelips Atlanta. I am dying to see what that big motor does on a rhino with 36v of power. It should be awesome and still legally a bicycle.

08-19-2009, 11:36 AM
Deacon, I meant to tell you this yesterday, but forgot. If you keep having problems with fuses blowing, you should get an AGU fuse holder (http://www.amazon.com/Scosche-EAFH-Single-Fuse-Holder/dp/B000KIV236/ref=sr_1_6?ie=UTF8&s=electronics&qid=1250677794&sr=1-6) and 60A AGU fuse (http://www.amazon.com/Scosche-EAGU60-4-amp-AGU-Fuse/dp/B001I1GO1E/ref=sr_1_1?ie=UTF8&s=electronics&qid=1250677794&sr=1-1), instead of giving up on the 36V idea. A 60A fuse would also allow you to run your 500 watt motor overvolted to 36V. The 500 watt motor running @ 36V is drawing 750 watts worth of power from the batteries, and is likely pulling fairly close to 60A of current.

08-19-2009, 05:07 PM
I got it running today with no fuse blown. I think the friction drive allows it to skip when under the most stress. That cuts down on the max amp pull, I think. But you are right I had been thinking 60amp fuse if it blew them.

here are the pics of the Rhino 2 the second story so to speak.


I'm pretty sure I am going to seriously love this bike. It climbs moderate hills while GAINING speed. It climbs slightly higher hills with hardly any loss of speed. Long hills are no problem for this bike. I just pedal before I kick the motor in to cut down on the current spike as much as possible other wise it just runs. I will have to get a speedometer to check out the speed of the bike.

This bike is fairly comfortable now. I had to move a few things to get them out of the ay but that is all done now. I think it is going to have a good range as well. I will keep the 350 watt to ride to the park since that isn't too far or too steep. It does have a higher potential for bike theft so I'll take the less desirable bike. It looks the same so people will get used to seeing it around and think they are the same bike anyway.;

Since they only let you post three I think I just gave you links.

08-19-2009, 06:49 PM
I like this version much better. Now the scooter wheel isn't inches from your butt, it's actually underneath you, making it much safer. I think you're going to like this one.:) Assuming those are three 12aH batteries, I'm gonna guess a 10 mile range @ 50% SOC (state of charge). Wal Mart sells bicycle speedometers for $10-15, and they even have odometers, but I guess you already knew that.

08-19-2009, 09:30 PM
yeah but my next purchase at wally-mart has to be a third battery tender. I charge each battery with it's own tender/charger. I have two for the 24v pack. I will just add one more.

I might get a speedo from Ebay. If I do that, my wife won't know lol..

The range is going to be hard to calculate till I just do it. They tell me the place to stop it is 11.75 volts per cell.. So in theory that gives me 1.5 effective volts per cell or 4.5 per pack... A mile of test track is .3 volts consumption.I figure max at about 15miles on the 12 ah batteries on it.

I have to be careful because the bike will operated reasonably effectively at even lower than 11.75 per cell. Because it is a 24v controller. In an emergency I could get a few more miles out of it. In the case of running it at 24volts as the starting pack when it went to the 11.75 it was already ineffective. But it actually runs pretty good at 24v so I could in effect flat line the batteries without realizing it. At least in theory,,,

08-20-2009, 01:10 PM
When I started with motorized bikes I built a china kit fume spewing gasoline bike. Then I built a dozen weed whacker and chainsaw bikes. Finally I turned my attention to Ebikes. I had very modest expectations. My goals was a bike that would do 10mph, climb most hills with minimum of assistance, go at least 10 miles per charge, be easy to replicate and easy to ride and maintain.

The Rhino bikes came after a lot of failed experiments. The Pat series were powerful and dependable but hard to replicate for the average builder... Hard to ride due to the drag effect on turns. Also the direct to the ground wheel made them a nightmare on fuses.

All the Rhino bike is really, is a pusher with the wheel on top of the rear tire. The Rhino bikes I have now will do the ten miles and hour, the range is ten miles with the 36v pack. They are easy to build and maintain... they are also extremely easy to ride. I think you could put the Rhino motor on any bike at all. The rear brake might be an issue but shouldn't be hard to work out on a mountain bike.

So my ebike experiment is over. I will probably work on trailers for a while. I would like a lighter weight easier to move around trailer. Otherwise I am satisfied with these bikes. That being the case I need to look for something else to play with for a while.

08-20-2009, 02:05 PM
Have you considered something that you and the wife could ride in (http://www.thebugleboy.com/nogasneeded/ngn.htm)? Or how about a more than 4-stroke (http://www.autoweek.com/article/20060227/FREE/302270007) engine? We await your step-by-step guide to either, in the near future.;)

08-20-2009, 06:22 PM
I think I'm going to work on a trailer next. The best trailers I have for my batteries use scooter wheels. They cost me about twenty bucks each. I checked today at the thrift store and I can buy a kids 12 1/2 bike for between 5 & 7 bucks. Those wheels would make a pretty good trailer I think. I might need a better design since im not sure about the axle sizes if they are the same or now.

I have a design to use the axles rather than a single axle but it is more trouble to use and store. I will have to take a look at what I can do. I can probably do a split axle for them.

08-26-2009, 12:26 AM
Seems I was too optimistic. I spent the day working on the rhino bike since I had a frame support come apart for lack of a double nut I suppose. that caused the motor to twist and throw the chain about a dozen times before I could get it home and fix it.

I had already decided there was no practical advantage to having the 350 watt motor since it uses the same amount of energy as the 500 watt. Why I have no idea, but it does. So I decided to use the 350 watt motor to build a direct drive friction drive to see what would happen. I am using a much larger wheel than I have ever used before (6inch lawn mower I had left from the failed experiment last week) and a 36v power supply. So tomorrow it should be ready to test.

I am just throwing it together so If it works I will have to go back and rebuild it to make it solid.
Right now I just wonder what kind of torque and speed it will get. After I find out I will probably be looking on ebay for a larger motor for the rhino.

08-26-2009, 10:15 PM
The direct drive works but the performance was not what it should have been. I think the plastic wheel is the killer. It really needs that big clunky rhino wheel. It had a pretty good speed but no torque to amount to anything. I have taken it apart for now but I don't know just yet I might go back to it tomorrow.

08-26-2009, 11:08 PM
Deacon, have you ever tried building a direct drive system, like the ICE-based systems use? Since you're able to weld, suspending the motor over the rear tire shouldn't be too hard, then you could just run a longer chain down the left side of the wheel to the 44 tooth sprocket (or 40, or 36, or whatever size sprocket you decide to use). That's what I would do, if I were you. Too bad I don't own a welder, and wouldn't know how to use one if I did own one.:)

08-27-2009, 04:10 PM
I own one but that doesn't mean I know how to use it properly.. Speaking of welders I think I have learned a lesson about buys rods in an open box. I have a whole box that won't seem to continue burning. I think that sitting around in the open box allowed the humidity to make them damp or something. My wife is doing volunteer work a the museum today so I might try baking them.

08-28-2009, 01:00 AM
Yeah, baking them at a low temp for a few hours would dry them out. Just make sure you have them out of "her" oven before she gets back home, or you'll be sleeping in the dog house for a few nights!:)

08-28-2009, 04:26 AM
the mfg says not to dry the ones I have oh well.

08-28-2009, 04:29 AM
I am giving some thought to building a rhino bike with 900 watt motor on a 16" wheel. I know it will fly but im not sure I have the nerve to ride it. I barely have the nerve to ride this one.

08-31-2009, 08:38 PM
Something occurred to me today while I was drinking coffee. If I mount the rhino top wheel when it is low on air and let the weight of the motor hold it down, then I can lock it in place without any adjustments at all. This will make the bike much more rigid and make it more stable.

I can control the tension on the rear bike tire by simply inflating or deflating the tire.

09-01-2009, 03:02 AM
That's an awesome idea, deacon. It may effect your range, though, because of increased friction. Try it, and let us know how it works. Hopefully it won't effect the range at all.

09-01-2009, 03:48 PM
well I plan to pump air back into it after I get it locked in place. That would lift it some of the rubber off the tire and increase the tension some. Still you might have the answer to my strange range fluctuations. I have had various tire pressures on that wheel. before I lock it down I will have to figure out the best pressure for that as well.

09-02-2009, 07:19 PM
I have been running the rhino bikes at 36v but I have a problem with the 500 watt motor. It actually has a sound which makes me think I burned up a bearing. I don't think that was caused by over volting alone but I believe it might have added to it. I ran the bike a few times with the chain too tight. I believe the binding of the chain along with the extra voltage to pull the motor even when it might otherwise have just shut down probably burned a bearing in the motor.

Even with the chain slack it has a rhythmic grinding sound. I can't hear it unless the motor is engaged, I think since that is the case, I will try the new motors I just bought with 24 volts instead of 36.

I do have a question. If I run a 600 watt motor with a 350 controller will it burn the controller up.

09-03-2009, 01:15 AM
If I run a 600 watt motor with a 350 controller will it burn the controller up.

A 24V 350 watt controller will only allow the amount of amperage to make it to the motor that equals 350 watts, around 12-12.5 amperes. A fully charged 24V battery pack is roughly 28V, and 28V x 12.5A= 350 watts. Note that the amount of current that the controller passes along to the motor is dependent upon the voltage that the controller was rated at. In the above example, if the controller was rated @ 24V instead of 28V, then it would allow 14.5-15A to reach the motor @ full throttle.

09-03-2009, 12:09 PM

I have decided to go back to the 24v and I have a spare 500 watt controller I just bought. If all else fails, I will get hold of a heavy duty switch. As a matter of fact I saw one in the shop somewhere. Thanks again.

I was thinking about my past experiments and I realized that the rhino bike pulls less amps than the PAT, using the same motor battery combo. I remember when I tried to take the pat to 36v it blew fuses left and right. The rhino does not blow them at all. I'm not sure why but it is a fact for me anyway. Might have to do with the skip factor of the Rhino when it gets to a tough hill. I might need to keep that in mind when I set the tension on the wheel.

09-06-2009, 05:36 PM
Funny but somehow it all came together with my last modification of the rhino bike last night.

Here are the things that make this bike perfect for me. There is nothing left to change.

1. It is a 20" step through frame. (easy for an old man with brain damage to mount.)

2' It has a coaster rear brake that finally works as it should (explanation later)

3. It has a front suspension fork from 24inch bike. (adds a little height to the front end so I don have to be bent forward. I can ride sitting straight up and it absorbs some of the road shock)

4. It has a 20" wheel in that 24" fork. (The bike is still pretty level in load so it doesn't lift the front too much.)

5. It has the rhino drive (my own invention rofl) (so the rear wheel has drag no front brake is needed. With the motor off in a few yards I could just foot drag it to a stop in case of chain brake.)

6. The rhino drive is fixed in place so the tension is controlled by air pressure. (I can deflate the tire completely in case of breakdown)

7. The rhino drive is powered by a 900 watt 36v power plant. It will pull even the worst hill with little or no help.

8. The bike has the short crank of a 20" bike which makes pedaling easy.

9. It has a 48 or 52 tooth chain ring (It allows me to pedal with the motor engaged almost at any speed and it also makes the coaster brakes work ten times better)

10. It has slightly taller BMX style handlebars (To keep them off my knees as I pedal)

11. The rhino drive was cheap and easy to build.

12. The batteries ride on a trailer. (That makes the bike lighter and easier to get in and out of the shop)

13. The batteries are inside a plastic took box ( I can remove it from the trailer for charging or storing the bike)

14. The trailer can be lifted (I can raise it and hook it in a lifted position so that I can roll the bike around without taking the trailer off and on every time.

I think that's about it. The last thing I did was putting on the larger chain ring. (It made a great improvement in the human element in the hybrid system. It also made the brake work ten times better)