old rhino @24v

I am continuing to lay out the parameters of the bike I plan to keep from now on. It is of course a rhino drive friction drive bike. I have downgraded from a 48v controller and power supply to a 24v relay system.

At 24volts the bike runs slower of course but it is a great setup as a helper motor. I can pretty much turn it on and just assist it with a pedal now and then. I do have to turn it off going downhill or it will run away. Actually more to save the batteries but so far they haven't been an issue. I don't ride very far at a time.

The frame of the bike is a 26inch mountain bike from the thrift store. I refitted it with a different set of handle bars so that I could ride sitting up comfortably. It has twenty inch wheels front and back so that it is easier for me to mount and dismount. I have the crank set from the 20" donor bike but the chain rings from the 26" bike.

I have no idea what the gearing for the pedals is. I use the largest ring on the three ring front sprocket and the regular coaster rear sprocket. I am pretty sure it is a mountain bike chain that I am using.

The trailer is a center hitched deal. This one is a big ole wire basket set on two 16" bicycle wheels. It is big enough to hold two 17ah plus two 12 ah lead acid batteries, for a total of 29ahs of 24v power.

One thing that makes me nuts on all these custom builds is that no kickstand ever fits them correctly. I always have to cut or weld to make them work.

I have been riding the 24 volts again to check out it's limits since I need some exercise. So far (knock on wood) I have not found a hill I couldn't manage seated comfortably. I did push a little too hard on one or two. I also learned that I didn't need to push so hard. The bike would have done fine, with less help from me. I'm not even sure I needed to help other than the speed fell some. I will have to keep working with it to know just how much help I need to give it.

Anyway that is the setup that I seem to be gravitating to. I might jack it up to 36 volts but I'm not convinced yet.

I put as ,momentary automotive universal horn button on the bike today and it lasted 10miliseconds Not much i can do since I put 24v through the 12v switch. I think I will avoid over powering the relay. I have the house type wall switch back on it now and it seems to be just fine. I might order a 24v switch on ebay.

I tested the relay with 36v and it blew the fuse when I popped it on. Fortunately it didn't damage the relay. However when I replaced the fuse I forgot to kill the on off switch and the bike ran off by itself lol. Since I have a trailer on the back which held it upright the bike ran around in circles until it developed enough force to turn the trailer over and throw the batteries out. That broke a wire and the motor died.

I put in a new fuse and put the batteries back in place and rode off. I blew another fuse at 24volts when I tried to start from a dead stop. I just ordered a circuit breaker the same amp as the relay and the old fuses. It is called self resetting does anyone know if they are any good.

I finally managed to get a good day weather wise and a good day bike wise so that I could give the rhino at 24v a good shakedown cruise, This is the one with no controller just a relay and a switch. To be honest I have taken the bike over a two mile track several times and it worked very well. So today I decided to give a good all terrain shakedown.

After my usual ride down to the mall, to walk, instead of coming straight home, I took off to the hardware store. I chose a route with a long steep hill. The bike did remarkably well on the hill until it got almost to the top. When it did the bike just shut down.

Since it doesn't have a controller, I knew that it wasn't a voltage thing. i got out of the road and let it cool off while I checked the wiring. The wiring was fine and after about five minutes it started right up. The circuit breaker had tripped. I have a 40 amp breaker to protect my 40amp relay. I rode the bike home from the hardware store and it died one more time on a steep not so long hill. Probably because the heat hadn't completely dissipated while I was in the store.

So now I am torn. I know that the bike does pretty well running at 24v with the relay, but I don't know what to test next. I have two 24v controllers, so I think the simplest thing to do would be to stick one of those and a throttle on the bike and ride it as 24 500 watts with a 40amp breaker for a while and see what it does. After a thorough evaluation, I will probably up one thing or another. The bike is a marginal performer at 24v but I do need the exercise. For pure transportation I still think 500 watts at 36v is minimum...

While I was adding the controller, I did a general overhaul of the bike. I had to replace the motor with my spare just because the mount wasn't steady enough. Since it needs a new tire I will rework it when I get one.

In the meantime I test rode the bike. After half a mile I decided that it was good enough to take to the mall, since I as half way there anyway.

The good the bad and the ugly of the controller vs relay. Control is better with the controller as you would expect. I can't and probably will never be able to prove it but power consumption is probably going to be ever so slightly better with the controller. If nothing else it runs the 600watt motor at 500 watts while the relay runs it wide open all the time.

The bike accelerates worse with the controller. The relay starts it wide open and and slips on the tire for a second until it catches up. Not so with the controller. I applies the power gradually. It is easier to start on a hill with the relay. Well it's a lot less work. The controller needs more pedal assist to get going.

My conclusion is, the controller at 24v is okay for me at this stage, since I want some exercise from the bike as well as transportation. If it were just to get from a to b, I would go with 36v for sure,. either relay or controller. Probably controller since the relay starts with a terrible jerk at 36v. It lifts the front wheel from the ground now and then when it kicks in.

I put the old rhino back to 36v. I just like to be able to power up a hill. I had the batteries laying around so why not. I think I will take a look on ebay for a cheap controller since these are 24v and will probably burn out soon. I burned out one I ordered from china. The on I am using came from tnc and was their heavy duty 24v model. I have used it before, so we will see how long it lasts.

kla63 said:

electric junk!!!!!

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Before I built electric junk I built gasoline junk ... It kind of like chicken nuggets parts is parts...

kla63 said:

who wants too worry about if you make it home cause you run out of charge !!!!!!

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I guess I do... I have absolutely no plans to build another gasoline bike. I have said here about twenty times, you need to decide how you are going to use your bike before you decide what to build. Then cut the manufacturer's numbers by a minimum of 30%. That is true of gas and electric.

Now, In my case I am not going to ride any bicycle farther than five miles from my home. I am not going to get on a vehicle designed to go ten mph as far as a fit or semi fit guy can pedal it and ride it 40mph and fifty miles from home before I turn back. I am also not going to ride it in the pouring rain. It's as much comfort as anything else.

Now I am not everyone, I know that, but then there is a famous line from "Rocky Horror picture show." The main character says to Susan Sarrandon, "But I didn't make him for you." That is the way I feel about my bike. I made it to please me, when it no longer does, I'll change it.

So what's new today. Today I rewired my batteries. I set it so that I can configure longer lasting packs as I need them. With Sla, I hate to drag around more than I need. I hope this will make the bike a little more manageable, I am still saving my pennies to use to build a modern battery pack.

But I do see your point. It certainly is a valid one, for those who build a bike to do more than I do with mine. I would drive a car, if I had to go a long distance. i am too old to consider riding a light weight bicycle more than ten miles at a time anyway, but again that is just me. I don't expect anyone else to do as I do.

PS my first build was a china kit bike so it isn't that I haven't tried the smokey dogs. By the way I am no environmentalist I just like to be different. When there were under a hundred members here I built a china girl bike. (ask Pablo where that name came from). Then when there were several hundred, I began to build weed whacker, and chainsaw bikes, then when there were lots of guys building those, i began building DIY Ebikes, When that fills up with people, I might try spring wound ones.