why I love friction drive

well.. friction drive is a wonderful way of making a motorbicycle, i have made 2 and both of them have worked flawlessly, i think ive built 3 chain drive bicycles, and all of them have had stupid issues with reliability. and also i find that a friction drive that hasnt got a centrifical clutch is very torqy, look at it this way i built that 31cc chain drive with a clutch and it would hardly haull my up my streets hill, i used another 31cc engine (identical) with a friction drive setup and no clutch and it pulled me up that hilll really well.

plus 1 for friction !
 
The only advantages I see of a friction drive is on a 20" bike (BMX) or a GoPed. Chains, belts or drive shaft for me thanks!



Just facts....not friction. laff

dnut
 
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scotto- said:
The only advantages I see of a friction drive is on a 20" bike (BMX) or a GoPed. Chains, belts or drive shaft for me thanks!



Just facts....not friction. laff

dnut
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Remember belts are friction drive, just grease one and see! LOL. Having bikes with chain drive, belt/chain, and pure belt, I just recently got a "friction" drive. I really like it. It is simple, quiet, and when the engine is not being used totally drag free, It does not matter what size wheel it goes on it will have the same power and speed so it leaves many options for bikes. Its not for every one, but if properly designed it has to be the most reliable system going.
 
I am an advocate for friction drive period. So whatever I say is suspect. I no longer build chain drive bikes, but I have and I can. Some of you no longer build friction drive, but you have and anyone can. Those guys who have built them and moved to chain have opinions that I value, even if I don't agree with them. For those who have never used a simple friction drive, I can only say. Don't knock it till you try it. It isn't for everyone, but I like it. Then again I'm not into speed. I simply want to go from a to b and not have to work my butt off to do it.

The biggest drawback for me is that it is that two out of three of my bikes are almost useless on a wet road, but I NEVER ride in the rain, anymore than I stand out in it. A broken water pipe in the road goes away pretty quickly, and it's why I have pedals on my bike.

The 40cc or so bumble bee bike I have isn't really very good on the hills, but the 3.5 hp I have is great on hills and over revs on the flats. Probably 2.5hp would be good all around. I am really glad to hear about the centrifugal clutch. I never used one on a motor, but I always felt it was just one more thing to go wrong. Both my gas bikes have a lift system for a clutch and it works very well. That is if you get everything in the right place, and correctly adjusted. I like step through frame bikes, but they are laid out wrong for the lift clutch controls. It needs to be up on that top bar. The layout on my bumble bee with the lift is the best so far. If I come across a cheap boy frame, I will probably pick it up for the 3,5 and just bite the bullet and move everything. I would love to have a 24" coaster for it. But only if the thrift store has a good one come in.
 
I have one 24" I run and e motor on. I think my current batteries will be unfit for use by the late summer. One of the gas engins will go onto it for sure. I am accumulating bike parts again. I swore when I cleaned out the shop last time that I would not store extra wheels and such but here I am again. I have 26" cassette rear wheels that I will never use. Gears on a motor bike are just about useless. Except to get a crippled bike home. 26" Bikes are dangerous for me to get off and on. Bad balance/
 
This hobby is all about the learning for me. Today I learned to replace a wheel spoke. The new motor broke a couple on a wheel i was using so I went out and got a donar bike. When it did it again I looked carefully and found out why. It was my homemade hinge. So I took spokes out of the old wheel and messed with it till I got one in the newer wheel. I'm right proud of myself.
 
Just like the saying goes: "Different strokes, 4 different folks". Make mine 4-strokes please....and hold the friction (to a minimum). That's all I can say.

dnut


deacon said:
I am an advocate for friction drive period. So whatever I say is suspect. I no longer build chain drive bikes, but I have and I can. Some of you no longer build friction drive, but you have and anyone can. Those guys who have built them and moved to chain have opinions that I value, even if I don't agree with them. For those who have never used a simple friction drive, I can only say. Don't knock it till you try it. It isn't for everyone, but I like it. Then again I'm not into speed. I simply want to go from a to b and not have to work my butt off to do it.

The biggest drawback for me is that it is that two out of three of my bikes are almost useless on a wet road, but I NEVER ride in the rain, anymore than I stand out in it. A broken water pipe in the road goes away pretty quickly, and it's why I have pedals on my bike.

The 40cc or so bumble bee bike I have isn't really very good on the hills, but the 3.5 hp I have is great on hills and over revs on the flats. Probably 2.5hp would be good all around. I am really glad to hear about the centrifugal clutch. I never used one on a motor, but I always felt it was just one more thing to go wrong. Both my gas bikes have a lift system for a clutch and it works very well. That is if you get everything in the right place, and correctly adjusted. I like step through frame bikes, but they are laid out wrong for the lift clutch controls. It needs to be up on that top bar. The layout on my bumble bee with the lift is the best so far. If I come across a cheap boy frame, I will probably pick it up for the 3,5 and just bite the bullet and move everything. I would love to have a 24" coaster for it. But only if the thrift store has a good one come in.
Click to expand...
 
scotto- said:
Just like the saying goes: "Different strokes, 4 different folks". Make mine 4-strokes please....and hold the friction (to a minimum). That's all I can say.

dnut
Click to expand...

Yeah thats whats cool as I pretty much have em all and each has its own virtues. I guess to complete the group I need a hydro drive and a gear drive.
 
To be totally honest I have to admit I had my first broken spokes with a friction drive. My home made side henge hit the spokes when the engine dropped. I corrected it but now I did have damage. And I think the different strokes thing is very true. When I first joined this forum, I had a heated exchange with a whizzer guy. He thought the china bike kits were trash and a waste of time and money. The quality and technology were just junk and anyone who bought or built one was pretty much an idiot. It never got nasty but our opinions got a little personal. We were both asked to cool it, so I try not to be too vocal or adamant in my opinions. I think everyone here these days is willing to just go along doing their thing and helping others do theirs. that's what keeps me coming back after I cool off sometimes.

We probably need a spot for friction drive separate from other other drives so that if you really feel there is nothing for you in friction drive, you can just avoid it. I usually avoid gas tanks and painting as I have nothing I can add and I really don't get into body work for cosmetic purposes, as anyone who has seen a picture of my bikes could attest.

Also I use a friction drive ebike, so there all kinds of bikes that can be friction propulsion. I am looking for a steam engine design. I think charcoal is the new fuel innovation. Stanly steamer on a bike. I saw the reproduction bike on utube and loved it. Or maybe it will be the flux capacitor who knows but I bet i can made it pull a friction drive.

By the way the best pulling bike I have uses a scooter wheel on top of the bike wheel. I just haven't found a way to run that with a gasoline engine YET. But that 40cc bumble bee looks good for it. Its all about the trying of new ideas.
 
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I was riding the BAM (Big A88 motorbike) today when I felt that the bike performed almost as good as a 109cc puch I rode to five hundred miles on a trip once. I am still working on getting the lift clutch spring adjusted so that I can lift the bike easily and still have enough tension to pull the hills. I'm close now. It pulls the hills fine and the clutch is pretty easy to lift. I might let a little more tension off the spring, just to see how it does.

The throttle cable is a pain to get adjusted for idle as well. If I ever have to replace it I'm going to add some adjustment that is easier to work than a cable stop at the end. But man that thing hums. Now if I can just fly under the radar with it, I good.
 
It looks like I finally got the bike where it should be. The clutch is easy to operate and the bike climbed the worst hill in my neighborhood with no problems at all. The idle works well and i found that the bike will pick back up from almost stall. That means I can make right turns without lifting the motor. I only have to lift it for a dead stop.

The 3.5 hp motor is overkill though. It also isn't very fuel efficient. It looks as though I can do about five or size miles total before the tank is empty. But I do like that it will pull those hills under power. Doesn't even need to slip at all to go right up them. It is fast enough that I can't catch the freewheel even on the steep hills.

Only problem I have is that it isn't legal. Of course I was told that it was 50cc and I have no reason to doubt that. The fact that I once had a small motorcycle that didn't perform any better means nothing.
 
As I said the 3.5 hp bike is a little over kill, but that mutha will climb a hill. I took it to the marina this morning for breakfast with my wife. She drove the car of course. The bike climbed the hills like nobody's business. It climbed hills I had trouble climbing with my china bike back in the day. It isn't fast. As I said before it is limited by the rpms of the engine being pretty much the same as all of them, the difference is that 3.5 hp engine does not bog down as much as the 40cc.

I am running a 3/4 inch inside diameter water pipe for a drive wheel. I run it smooth to save on tires and it works as well as anything I could ask for. I don't want to go over twenty or so and it does that easily. Best of all there is nowhere I wouldn't take this bike.

Of course now I want the harbor freight four stroke replacement for this engine. I hope it will last a lifetime though and I never need it.

One interesting thing. This morning the engine stalled due to a motorcycle blocking the road and i didn't get the lift pulled in time. Since the recoil starter broke, I could not get the rope wound while sitting on the bike and I couldn't get off in traffic, so I planned to ride it to a spot where I could wind it up.

On the way I had a little speed up so I dropped the engine on the tire. The engine had never done a drag start before but sure as heck it fired up just before the bike would have stopped. I was shocked, not so shocked that I didn't ride off.

I learned one thing for sure, the motor would shut down if full brakes were applied with no throttle, and it actually might drag start. That is my testing for the afternoon.
 
I made a slight adjustment to the lift/drop handle to get a better angle, then took the bike out. I killed the engine at the top of the hill then pedaled it down a little then dropped the engine and it started right up. Why it wouldn't do that before had to be the drive wheel. It works really well now. I'm a happy bicycle rider.

No where I can't go, top of the world Ma...
 
Today i removed the 26" wheel and replaced it with a 24" one on the front;. I now have a 24" on the front and a 20" coaster wheel in back. That seems to be the ideal configuration for me. Especially with that big of an engine. If I come across a 24" coaster bike I might just go with it. If not, I may reconfigure the bumble bee like the one I just finished.
 
NO NO friction is my friend. I can never get enough friction lol... Well there are times, like when I skidded across the pavement,. after I left the bicycle reather suddenly. I could have used a little grease that day..
 
I switched my attention from the wonderful but illegal 3.5 hp BAM bike to the Bumblebee that is legal. I know it will never do what the BAM does but it isn't all that bad in it's own way. On the flat it is pretty close to the BAM it's on the hills around here that it isn't as nice a ride, but I moved the motor to a different frame to see if I couldn't help it out a little.

I moved it from the 26" Bike that threw me on the grown twice, to a 24" that had been my ebike. I may move the ebike to the 26" frame after I do some modifications to it. Or I might combine the two into a single bike and get ride of the 24" frame. I would like to keep it because it still has gears, and they are helpful with the smaller engine.

The problem is in frame itself. For one thing it is a sissy frame which makes the lift clutch a pain to setup throw wise. Then there are issues with the pedals. For some reason the pedals are set too far back. The angle on them makes it very clumsy to pedal the bike. With the smaller bike it becomes an issue.

I could probably switch the front fork and change the rear wheel and use the 26" bike just fine. It would drop the thing an inch front and back. That might be enough, but I want to give the 24" a chance before I do all that.
 
I no expert on bikes and design but the 24" frame is dimensioned for a given range of users. If you are tall its probably an issue. Im 5 10 and have very little problems wuth the 24". I dont see why swapping the wheels over to the 26" frame would not be ideal if the motor will still engage the tire. Originally the Bumble bike had a hand clutch as I mentioned. Would be real easy to set up. Nice at stops. With the metal ring to hold the clutch for you, you could start the bike, get ready, the pedal off and engage the clutch. If you are interested, I can send you a pic of the linkage, it probably came with your engine.
 
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