Chains, tensioners, carbs...Ever wonder?

Bikeguy Joe

Godfather of Motorized Bicycles
Jan 8, 2008
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I Noticed a couple of things this past week while working on the bike and had to ask others thoughts.

Chain- Loose, sloppy, ect. BUT, what if it were made that way so that alignment didn't have to be perfect, like a derailuer chain?

Tensioner- I'm talking about the super cheapy...the "no bearing" job. I noticed that it is really tight, but if you turn it a couple dozen times, it loosens up a little bit. Then, run it for ten minutes or so and oil it. It seems to be made of nylon, or mylon like plastic running on steel. If the chain is not over tightened, it makes a cheap, effective bearing. I ran one for 500 miles with no problems, kept wondering what all the fuss was about. I sold the bike so I don't know of it's ultimate fate. I am currently going to run one as long as it take to destroy it, and see what happens.

Carb- Terrible, I have seen more complex and adjustable carbs on EVERY model airplane engine I have ever delt with...even down to .09 cubic inches, only the Cox Muffler Ring throttle is more primative. O.K., I can't think of why this is so....maybe I'm missing something. The cap does screw down without crossthreading if you gently push down on it.:ride:
 

5-7HEAVEN

Well-Known Member
Aug 2, 2008
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Joe, it's all about profit. The less you pay for labor and materials, the more $$ you as a distributor/manufacturer get to keep.
 

old motorbike

New Member
Sep 21, 2008
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Yes, great thoughts, my original chain would bind or jump off if it was too tight. Had to be loose to work.
I went the shifter route, but wonder how long the de- railer chain will last?
I'm with you about the carb, and surprised it works as well as it does. I'm still looking for a reasonable replacement with better drive ability and adjust ability. I had a great one on my old mini-bike, but it was very sensitive to dirt. Been looking at pocket bike carbs, maybe one will work?
 

Dave31

Moderator
Staff member
Mar 1, 2008
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Aztlán, Arizona
Well Joe you know how I feel about the tensioner. I am still using my stock "no bearing" tensioner and will have six years on it in May 09 and last I figured around 4,400 miles.

All I have ever done is clean it up and grease it with synthetic wheel bearing grease often and always after a ride in the rain.
 

misteright1_99

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Mar 21, 2008
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Treasure Coast, Florida
The chain and tensioner I thought were poorly made, and the chainstay mount I thought was a dangerous idea, maybe because I was NEVER able to get my sprocket centered "perfectly", and would always, and still do have a "tight then loose" condition. Therefore the spring loaded tensioner.

I think the stock carb does a fairly good job for as simple as it is. Mine worked good, did not leak and after drilling the hole for the idle circuit, idled like a motorcycle. The ONLY reason I changed it was it does not flow enough for the expansion chamber and porting I did.
 

Bikeguy Joe

Godfather of Motorized Bicycles
Jan 8, 2008
11,843
235
63
up north now
Well Joe you know how I feel about the tensioner. I am still using my stock "no bearing" tensioner and will have six years on it in May 09 and last I figured around 4,400 miles.

All I have ever done is clean it up and grease it with synthetic wheel bearing grease often and always after a ride in the rain.


That's what I'm sayin'.

Same with the chain....it SEEMS loose, but if it was tight, then you woudn't be able to get away with much.
 

Dave31

Moderator
Staff member
Mar 1, 2008
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Aztlán, Arizona
That's what I'm sayin'.

Same with the chain....it SEEMS loose, but if it was tight, then you woudn't be able to get away with much.
I agree, not only that but having too tight of a chain will cause vibration and noise and puts stress on your tensioner which will cause it to fail sooner.

I look at my tensioner not so much as a "Tensioner" but more of a guide for the chain.
 

Bikeguy Joe

Godfather of Motorized Bicycles
Jan 8, 2008
11,843
235
63
up north now
The crappy russian clutch lever is the same way.

Looks crappy, but if you "work it" a little, it's perfectly useable and in fact quite stout.

Sure it doesn't LOOK like slick American engineering, but it does the job.
 

Bikeguy Joe

Godfather of Motorized Bicycles
Jan 8, 2008
11,843
235
63
up north now
Anyhow, I have a bike I purposely used all the "cheap crap" parts on just to see how long they last. Yes, even the stock plug and wire (it has blue spark, read my signature).
 
Sep 20, 2008
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Clearwater, FL
web.tampabay.rr.com
"The cap does screw down without crossthreading if you gently push down on it."

Another thing that really helps:

While gently pushing down, turn the cap counter-clockwise until you feel it click. This helps to square it up and "find" the first thread. Works every time.

Jim