Chain and sprocket problems

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maxsideburn

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Dec 7, 2009
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Ok, went out to try and start up my bike for the first time and had a failure.

The chain kept coming off of the rear sprocket and then the master link (the little "clip" part flew off).

Where do I order a new master link? and How can I get my rear sprocket more in-line with my motor?

I think one of the reasons that my chain is coming off of my sprocket is because the motor and sprocket are not very much in line with in-line with each other. I assembled my sprocket with both rubber rags and yet the chain still seems to have to angle in toward the sprocket, also my chain is extremely close to my rear tire.

Oh, and while I'm at it, I cannot figure out what's wrong with my rear wheel. After taking it apart to do the sprocket it is just giving me problems. After I roll the bike forward a little bit it seems to have play in the rear axle. I have to pull it all apart, tighten it all down, and then it does it all over again. I'm certain it has something to do with the coaster brake setup....I just want it fixed.

Any info appreciated. Thanks.
 
GearNut

GearNut

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maxsideburn

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that looks like a royal pain, can I just order a wheel with no brakes on it and use a caliper type hand-brake? if I can order something like that how would I know if it has the correct sprocket for my bicycle (for the pedals)?

please help, I'm fairly mechanically inclined, but bicycle stuff is pretty new to me.
 
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spacey

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May 7, 2011
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You have a pretty good chance of getting a sprocket that will work ok for your crank.
You could count the number of teeth on your old wheel. If you are running a wider tire, 2.125 +, check the with of the rim before you buy a new one. Or go with a narrower tire. Wider tires need wider rims. Use a different sprocket mount,rag joints are a pain to line up. Look around the sponsors sites, you'll find one. If you have a front pull break you might want to buy a dual break leaver if you go with a non-coster hub.
 
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maxsideburn

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I'm running whatever the bike came with. just plain old beach cruiser type wheels and tires.

what kind of different sprocket mounts are you talking about? I've seen the full sprocket adapter sets, but not any different kind of mounts. problem with the sprocket adapter sets I've seen is that I don't know how they work and if I'd need a special wheel....as I said, I know nothing whatsoever about bicycles other than how to ride one.
 
GearNut

GearNut

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Aug 19, 2009
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I am betting that you have a coaster brake if you have a beach cruiser bike. Does the rear brake operate when you pedal backwards?
If so, then these adapters would work perfectly for you:
Sportscarpat's:http://motorbicycling.com/f23/sprocket-adapters-30054.html
or
ManicMechanic's:
Manic Mechanic
I have a ManicMechanic adapter and it works quite well.
Sportscarpat's adapter is newer to the market and seems to have a better clamping design to it.
If you have an oddball hub size, Sportscarpat can custom make an adapter to fit your needs.
 
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maxsideburn

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let's just assume I'm trying to go as cheaply as possible and get this bike running...is there a wheel I could buy that would work better with the rag joint? apparently I just don't comprehend how a coaster-brake axel works and I've either broken it or can't get it back together properly.
 
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spacey

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May 7, 2011
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springfield, oh.
Hi,

First, I am not a bike mechanic, just an average joe dick'n around the garage.
Not to be fresh but do yourself a favor and start over. My first bike I bought form a guy that got to where you are and gave up. I found it easier to start with a working bike.

Where you able to assemble the rear sprocket with the break arm in place ? It usually needs to be bent to clear the sprocket . I just bent the break arm with a vice and a hammer. You may also need to cut down the dust cover so it clears the backside of the sprocket. That could be the reason your hub isn't spinning free .

It's a good idea to center the sprocket on the wheel. I beveled the backside of the sprocket hole so it sat on the hub a little better. To check the center I flipped the bike
on a bench, fit the wheel, ruffly fitted the sprocket and hand clamped an adjustable square to the frame to use as a guide. Slide in the square so it makes light contact with the sprocket and adjust the hub tension till it's true. Be sure to check the top run early on in the process , just reposition the square so it gauges the top of the sprocket. I used a block of pine and a hammer to tap it into round.

That should get you true enough that your chain can be alined. Make sure when you mount your motor you have a solid mount, (no rubber shims and plum) the motor wants to shift to the left under load . Make sure your tensioner runs true, some folks had to bend them, I built mine without it. If the chain rubs the tire get a thiner size, 1.90 usually works but I went with 1.75's.

Good luck, I hope this helps ....

Mark
 
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maxsideburn

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My motor is mounted solid straight to the frame. I cut the dust cover and did not have to bend the brake arm, but I did have to remove it to get the sprocket in place, then replaced it. It clears the bolts, not by much, but enough to not be a problem.

The problem that I am having is that I can tighten everything up and it seems fine...but if I ride the bike down the street and back (under pedal power, haven't started the motor up yet) when I get home the wheel has play in it. I have to take it apart again and tighten it all back down.

For some reason just the act of rolling the wheel is loosening the axle (or whatever the **** it's called) and it starts having side-to-side play in it. Apparently I'm not understanding how to put it back together or something.

I just put the brake arm and hold it with my left hand while cranking down on the nut on the other side with a wrench in my right hand. It seems all tight and secure, until I roll the wheel for a little while and it comes all loose again.


btw, the BGF kit claims it comes with a heavy duty chain (#415/#50), so which one is it? #415 or #50? again, I don't know anything about bikes, chains, etc...
 
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spacey

New Member
May 7, 2011
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springfield, oh.
Some hubs have a spring for the break screw inside the hub, check on the break arm side when you tighten it up some times you have to turn it a bit to get it to seat. Other then that I'd look at the break arm and make sure it's not slipping off the nut. Can't help you with the chine size, I've only noticed the #415 , etc., reference.
 
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maxsideburn

Member
Dec 7, 2009
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Scott, LA
ok, talked to a guy at a local bike shop. he showed me how to tighten up the wheel so that should be good. he didn't have the right master link for my chain, so he sold me a much smaller chain that he claimed they used on motorized bikes...but it doesn't fit at all, the holes in it are too small for the sprocket inside the motor.

so....I still have to figure out my chain problem.
 
2door

2door

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maxsideburn said:
ok, talked to a guy at a local bike shop. he showed me how to tighten up the wheel so that should be good. he didn't have the right master link for my chain, so he sold me a much smaller chain that he claimed they used on motorized bikes...but it doesn't fit at all, the holes in it are too small for the sprocket inside the motor.

so....I still have to figure out my chain problem.
Click to expand...
Go to Ace hardware and ask for #41 chain and a master link. They sell it in ten foot lengths. You'll need to cut it to size.

As far as your brake/wheel problem; did you reinstall the brake arm clamp to the frame that keeps it from spinning? The brake arm must be attached to the chain stay or when you apply the brakes it will simply unscrew and cause the problem you describe.

Tom
 
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maxsideburn

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Dec 7, 2009
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Scott, LA
I was tightening it up to simply holding the brake arm in my left hand and cranking down on the 15mm bolt on the other side....I didn't realize that I needed to remove that 15mm bolt, tighten by holding the brake arm and putting a wrench on the other side of the axle, then replacing the 15mm nut to lock it into place.
 
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spacey

New Member
May 7, 2011
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springfield, oh.
maxsideburn said:
I was tightening it up to simply holding the brake arm in my left hand and cranking down on the 15mm bolt on the other side....I didn't realize that I needed to remove that 15mm bolt, tighten by holding the brake arm and putting a wrench on the other side of the axle, then replacing the 15mm nut to lock it into place.
Click to expand...
Ok, I see where your problem was now ...
 
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