Chain Slips at High RPM's.

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Traveller

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Nov 14, 2009
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My chain is slipping at high speeds (~20+mph) and either falls onto the rag joint, or out on the axle. Why? NOTE: I could go hundreds of miles, litterally at 15-20MPH and the chain wouldn't jump off. I removed as many excess links as possible.


The sprocket (non-offsetted 44T) is running true. The only thing that I changed was the iddler which I put on the top slanted part of the frame, so it makes contact with the chain on the way back into the engine.


--Traveller

I am running a stock 80cc SkyHawk setup on a 26" cruiser bike.
 
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R

Riding Rich

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Aug 14, 2009
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Sounds like Alignment too me.
The motor sprocket is a little offset from the rear sprocket.
I use spacers behind the rear mount to take up the chain slack

I never liked the tensioner.
Seems to be an accident waiting to happen.

So it's one or the other

A)
the chain is too loose and comes off with higher velocities.

B)
the sprockets aren't in perfect alignment and chain comes off at high velocity.

Just think about how many feet per minet that chain is traveling.
At higher speeds it's movin.
 
Bikeguy Joe

Bikeguy Joe

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Jan 8, 2008
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Traveller said:
My chain is slipping at high speeds (~20+mph) and either falls onto the rag joint, or out on the axle. Why? NOTE: I could go hundreds of miles, litterally at 15-20MPH and the chain wouldn't jump off. I removed as many excess links as possible.


The sprocket (non-offsetted 44T) is running true. The only thing that I changed was the iddler which I put on the top slanted part of the frame, so it makes contact with the chain on the way back into the engine.


--Traveller

I am running a stock 80cc SkyHawk setup on a 26" cruiser bike.
Click to expand...
The problem started when you moved the tensioner?

Read my signature.
Then put it back.
 
2door

2door

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Sep 15, 2008
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Not to start another tensioner debate but they do help with alignment if the engine and wheel sprocket are not or can not be in perfect alignmemt. The tensioner wheel will help guide the chain onto the rear sprocket. Mounting it as you did, on the top chain run, it will only help hold the chain tension but at the wrong time and place.
Tom
 
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captainrichhill

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May 31, 2008
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Bottom run of chain. Too much force during load (running). Check your tension of the chain. 1/2 to3/4" slack. More then that could run into problems.
 
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Riding Rich

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Aug 14, 2009
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Get rid of the tensioner and perfect alignment and tension you'll love it.
Why keep something eles around to break........................
And lock you rear wheel..........................
And break you spokes ?????????????????

Use the shims in between the rear mount and the motor.
.032 inch shim = allmost 1 chain link.
Get the tension good without the tensioner and you are Golden.

I used a tensioner for an hour.
After that it was By BY.....

Unless of course you make that custom skate wheel!!!!!!!!!!!!!!!!!!!!!!!111111
 
FileStyle

FileStyle

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May 27, 2008
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the chain Idler is to direct the chain onto the rear sprocket, therefore it does need to be on the bottom chainstay. if on top ,there is nothing to direct chain to sprocket!
I concur, put it back! the skatewheel method is what I have.
 
Cabinfever1977

Cabinfever1977

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Mar 23, 2009
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Put it back where it goes,it helps to guide the chain onto the rear sprocket even if you dont need one. i mounted a metal strap from frame pole(near peddals) to tensioner to another framepole(after tensioner at rear) and it wont go into my wheel ever.
 
T

Traveller

New Member
Nov 14, 2009
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Southern CA
Riding Rich said:
Sounds like Alignment too me.
The motor sprocket is a little offset from the rear sprocket.
I use spacers behind the rear mount to take up the chain slack

Just think about how many feet per minet that chain is traveling.
At higher speeds it's movin.
Click to expand...
Riding Rich, I already got the sprocket aligned using spacers on the inside of the dropouts.

Besides the idler location is anybody else experiencing problems with chain slipping at high speeds?
captainrichhill said:
Bottom run of chain. Too much force during load (running). Check your tension of the chain. 1/2 to3/4" slack. More then that could run into problems.
Click to expand...
Regarding the sprocket I will "downgrade" to a smaller 38T/40T sprocket from pirate cycles which will reduce the chain speed at 23-25MPH, thus avoiding the problem of the chain moving to fast at high speeds. Will I get this speed at half throttle?

Have any of you drilled holes (in a circle) around the sprocket and inserted metal pins, so that if the chain did fall off it wouldn't send you to a screeching halt (assuming it fell on the rag side)?

--
 
Venice Motor Bikes

Venice Motor Bikes

Custom Builder / Dealer/Los Angeles
Mar 20, 2008
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Traveller said:
Have any of you drilled holes (in a circle) around the sprocket and inserted metal pins, so that if the chain did fall off it wouldn't send you to a screeching halt (assuming it fell on the rag side)?

--
Click to expand...

If you just install the sprocket as straight as possible, install & 'pin' the tensioner correctly, or get rid of the tensioner & adjust both chains correctly... You won't have to worry about the chain coming off! ;)
 
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