Chain falls off?

You know I was really surprised when I found out that these
new scooters only have a chainstay on one side, nothing holding the wheel on other side but variator, does that make it less safe?
don't blame the tools :)

I have no problem with rag joints, but the tight chain / loose chain is not from alignment front to back sprocket but "concentric alignment" with the wheel

The wheels on the bus go round and round :)
 
^+1 big man.

I would also like to add that the instructions (if that's what you can call them) that are included with the kits specify that 12 gauge spokes be used and that 14 gauge are questionable.
 
Desert Rat said:
You know I was really surprised when I found out that these
new scooters only have a chainstay on one side, nothing holding the wheel on other side but variator, does that make it less safe?
don't blame the tools :)

I have no problem with rag joints, but the tight chain / loose chain is not from alignment front to back sprocket but "concentric alignment" with the wheel

The wheels on the bus go round and round :)
Click to expand...

Sorry bro, But front to back alignment, (Back/forth alignment,) and concentric alignment are the same thing.
http://en.wikipedia.org/wiki/Concentric
Side to side or left/right alignment, (the wobble,) is what I think you meant to describe
fatdaddy..
 
karryhunt said:
I'll admit that I have only installed a few rag joints. My brain kicked in and told me to look for better means of driving the bike. I can guarantee that there is not a person on this forum that could make the install any better than I. They were perfectly aligned and I still got tight chain/loose chain syndrome.

I have only read on this forum about the failures resulting in broken spokes which is enough for me. I guess you don't think that's enough to worry about.

Here's something to ponder.

You buy a new bike, install your kit with the rag joint, enjoy the ride for a short time, oops, broken spokes, replace 14 ga spokes with 12 ga spokes, cost $75, light bulb comes on I should have bought the $65 adapter. Think about it this way, with a rag joint your only using 18 of the 36 spokes to drive your bike, with a hub adapter the torque is distributed evenly over the entire wheel. Dosen't that make sense???
Click to expand...

The rag joint works fine if you line up the sprocket within 1/16" run-out in all directions. You can eyeball it to get it that close.

If the sprocket is mounted correctly and the chain is still loosening/tightening to the point of throwing the chain, it is most likely the result of the two sprockets out of alignment w each other. Again you should be able to see this with the naked eye fairly easy. Or, the width of the sprocket (usually drive sprocket) is causing the chain to bind. Going from a 415 to a 41 chain will resolve the issue.

I'd take a two-three piece aluminum adapter over a rag joint any day just for the R/R time savings. However the rag joint works fine considering it's free with a kit. I prefer to replace the crappy screws/nuts that come from china with harder ones so they don't strip after a few tightening/loosening's.
 
dodge dude94 said:
^+1 big man.

I would also like to add that the instructions (if that's what you can call them) that are included with the kits specify that 12 gauge spokes be used and that 14 gauge are questionable.
Click to expand...

Hey Dodge, Good idea but they will never do it. They also wont tell you to replace the cheap chinese mounting studs and bolts with a better grade. Or tell you to replace the plug wire and boot AND the spark plug with something better. Along with a lot of other things that should be done. The people that make these engines and (try to,) write the instructions DON'T CARE about you, Only your money.
fatdaddy.
P.S. I just remembered trying to read the first instruction booklet I ever got. It had me on the floor laughing, TEARS rolling down my face for hours. It was a challange to say the least.
 
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Brusier said:
The rag joint works fine if you line up the sprocket within 1/16" run-out in all directions. You can eyeball it to get it that close.

If the sprocket is mounted correctly and the chain is still loosening/tightening to the point of throwing the chain, it is most likely the result of the two sprockets out of alignment w each other. Again you should be able to see this with the naked eye fairly easy. Or, the width of the sprocket (usually drive sprocket) is causing the chain to bind. Going from a 415 to a 41 chain will resolve the issue.

I'd take a two-three piece aluminum adapter over a rag joint any day just for the R/R time savings. However the rag joint works fine considering it's free with a kit. I prefer to replace the crappy screws/nuts that come from china with harder ones so they don't strip after a few tightening/loosening's.
Click to expand...

Yep, 100%.
fatdaddy.
Think I'll go find another thread to mess with for a while.
 
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I'm wondering about the poor OP of this thread. We must have scared him off. He hasn't been back since the first page. When he saw what he started he probably slinked off to his garage to hide. :)

Tom
 
fatdaddy said:
Hey Dodge, Good idea but they will never do it. They also wont tell you to replace the cheap chinese mounting studs and bolts with a better grade. Or tell you to replace the plug wire and boot AND the spark plug with something better. Along with a lot of other things that should be done. The people that make these engines and (try to,) write the instructions DON'T CARE about you, Only your money.
fatdaddy.
P.S. I just remembered trying to read the first instruction booklet I ever got. It had me on the floor laughing, TEARS rolling down my face for hours. It was a challange to say the least.
Click to expand...
My instruction booklet wasn't THAT bad. The pictures sucked and it was a copy of a copy, but that's besides the point. :D

But either way, my manual for my Grubee kit said that you could use 14 ga spokes but they recommend that you use a wheel with 12 gauge spokes or have it re-spoked. I know the half-way decent cruisers like my Huffy have 12 gauge spokes. I know my improperly installed tensioner would have taken out my entire wheel if it hadn't been for those spokes and the curb I wrecked into would have taco'd the front. Steel rims + 12 gauge spokes = me happy. :D
 
All I know is that I have installed a LOT of ragjoints over the years and have NEVER ONCE broken a spoke on a wheel using the kit ragjoint. When correctly installed, they are perfectly adequate for the job.
I will admit a hub adapter is MUCH easier for a newcomer to install centered.
If you have the budget, use an adapter.
If you don't want to spend almost as much as the entire kit just to mount a sprocket, use the kit ragjoint. It works quite well when CORRECTLY done.
And Karryhunt? If you were still having loose-tight issues, you did NOT have things correctly installed. If you had, there would not have been any change in chain tension when rotating the wheel. I have heard of kit sprocket with the center hole drilled off center, but have never seen one myself. I have never had any trouble assembling ragjoints properly. All it takes is time and patience, especially if you shim the hub to center the sprocket before tightening the ragjoint.
 
Thanks Dan, It needed it, due to me for a large part of it. Sorry to everybody that put up with all that.
But yeah, Back to the topic.
I think it's all been said before, on this thread and many others. Rag joint or hub, don't matter. If you have the engine straight and tight, The rear sprocket tight and in line with the drive sprocket you shouldn't have any problems. But still, this seems to be a common problem, especially with the people new to motorized bikes. I don't think they realize how important this issue is. This is about the only part of the build I call "critical" besides a straight, tight engine mount. I've seen a few guy's give up and cuss the entire motorized bicycle industry over chain issues. The advice I try to give is, Don't give up on it. There are thousands of people riding motorized bikes, a lot of them are right here on this forum. So for the newbies, Don't get all frustrated, simply go to where you can find some answers, Right here would be a good place to start.
fatdaddy.
 
I see the problem as one that is hard for the non-mechanical to understand. The guy who can just get by changing the spark plug on his lawn mower will not see the technical significance of proper chain/sprocket alignment and/or engine mounting.

The adds for the kits make it appear as if anyone with a screwdriver and pair of pliers can install a kit on a bicycle (in one to two hours) and ride away into the sunset, fat dumb and happy. It just ain't so. Understanding the concept of a roller chain drive and the importance of chain/sprocket alignment is just simply above the skills of many. This is what causes so many problems with the much maligned 'rag joint'. The builder MUST comprehend the importance of getting the thing installed correctly, centered and wobble free or he/she will have chain derailment issues that will seem insurmountable.

No, the rag joint isn't perfect, but it will suffice and serve the builder well IF installed properly but that takes a certain amount of mechanical understanding and skill. The learning curve can be frustrating and even disastrous for the new and unskilled builder.

Those of us who have been turning wrenches, fabricating, engineering and building mechanical devices for years have an innate understanding of what it takes to make a mechanical thing work. Those who have never been faced with those challenges will find that motorizing a bicycle isn't as easy as the sellers of the kits would have them believe.

They see the adds and think, "Hey, it's a bicycle. How difficult can it be?" They don't comprehend that a bicycle, especially a motorized bicycle requires a certain level of technical understanding that everyone doesn't possess. Some are born with that appitude, others must learn it but they usually have to learn the hard way where those with the natural skills will find it easy, even elementary.

I could go on but I think I've covered it enough. Oh, and this is just my opinion. Take it with that proverbial grain of salt.

Tom
 
One of my favorite things about these things is the forced education that comes with them. I did fairly well with the regular wrenching stuff before trying a kit on a bike. But they opened up a whole new world for me. Aside from parts and components to be made to fit, I started fabricating small and easy parts. The math gets complex. The parts get to be puzzles and the tools get to be an addiction.

I honestly feel for folks when it is just not their thing to turn a wrench or worse, think it is as easy as the web pages and ads say. It's not. (why most of us call 'em builds and not assemblies) It is hard. Just the language can be confusing.

But the first time she fires up and starts moving you down the road.... It is a high like no other. LOL, and in my case, the first time, lasts about 12 seconds before, because of my not understanding, the tensioner turned into my spokes and stopped me dead. lol.

Went out and bought another bike. (didn't know to just buy another wheel)((and alter the chain stay))

Really, really cool part of this crazy is you folks. Not kidding, you guys and the community. motorized bicycles taught me math, wrenching, physics and introduced me to this community. Not meaning any thing crazy but I have met some of the best people here. Just to night, I was laughing at some thing and Carol walked past. She stuck her head in and asked "What?" I replied; "2Door said "sorry, not you dan. I meant the other boneheads" She said, and I quote; "Tell Tom I said Hey"

Tom and I live on opposite sides of the U.S., will probably never shake hands and my wife knows him by name.


So, if your chain falls off, just ask why. Folks here look out for each other.
 
stephen1 said:
my chain was popping off at first just move the chain tensioner tighten it up works good now
Click to expand...

Sometime a tensioner adjustment,(back or forth, even left or right,) can help out chain alignment. But this only works if you have the alignment very close to begin with.
Also, Something else I've been meaning to bring up, And since now we're talking tensioners. I'm sure all the builders that have been doing this for a while have noticed that the tensioner does NOT run in line with the chain. This leaves the chain to start at one side of the roller and finish out on the other side. The chain DOES NOT run straight and even on the roller. If anyone wants to tell me how they solved this problem I'll tell how I've been doing it for years. (This is a TEST of the EBS,(emergency bikebuilding system.) This is only a TEST.)
fatdaddy.
 
FD,
Almost without exception the chain stay is not parallel with the chain path. There is usually a taper to the frame that will require the tensioner bracket to be 'twisted' to align the wheel with the chain. If the wheel is perfectly aligned with the centerline of the chain you might see it move from side to side but there will be little stress against the skirts of the wheel and it shouldn't hurt anything.

Tom
 
2door said:
FD,
Almost without exception the chain stay is not parallel with the chain path. There is usually a taper to the frame that will require the tensioner bracket to be 'twisted' to align the wheel with the chain. If the wheel is perfectly aligned with the centerline of the chain you might see it move from side to side but there will be little stress against the skirts of the wheel and it shouldn't hurt anything.

Tom
Click to expand...

Hey bro, Not fair (LOL.) OF COURSE the motorized bicycle Guru knows the answer. But yeah, Thats it. Just SOMETHING ELSE the makers of these kits aren't gonna tell ya. And another thing that falls into the "trying to get it perfect" column.
fatdaddy.
 
anyone ever make a really good measurement of the valleys of the sprocket in relation to the tips of the teeth - I sometimes feel that perfect alignment according to the teeth still leaves the chain with some unexplained run out like the valleys aren't concentric with the tooth-ends
 
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