my first motorized bike. few problems & questions

[Jprice1707]

I'm new here and I recently built my first motorized bike about 2 months ago and everything was fine until I had to replace the rear rim & tire. I had hit a rock and bent the rim. After I replaced the rim, the chain came off (the tensioner bent back towards the spokes) and it got ugly. Busted the spokes, bent the sprocket and busted the tensioner.

I haven't ordered a new sprocket and tensioner yet, but here are my questions. Why would the tensioner keep pulling towards the rear tire spokes? It did that once before the accident happened, I caught it in time.

Also i noticed that my chain keeps touching when the clutch is engaged. (Picture provided) what would cause that?

And last, when I took the cover off on the motor where the other sprocket is located, this little "piece" fell out. Is that also broken? Or is it supposed to be like that? When I first built the bike, I don't remember the little bar being loose. I provided a picture to better understand what I'm trying to ask.

I'm still learning so I probably sound like I have no idea what I'm talking about.

Thanks

 

[Jprice1707]

Also, I know the chain looks like there's a lot of slack, but it only does that when the clutch is pulled in.

The motor is a Zeda 80cc, if it matters.

Thanks

 

[wan37]

I will tell you my way is the piece is call the bucking bar it goes in like the picture you have not broken . Now chain is real lose I like mine really tight but others say firm . Here’s away to tell from the drive (smaller) gear to about 3 inches out squeeze them together top to bottom if they touch to lose idea spot would be 1/4 inch gap from the top to bottom.

 

[DAMIEN1307]

I haven't ordered a new sprocket and tensioner yet, but here are my questions. Why would the tensioner keep pulling towards the rear tire spokes? It did that once before the accident happened, I caught it in time.

Also, I know the chain looks like there's a lot of slack, but it only does that when the clutch is pulled in.
The motor is a Zeda 80cc, if it matters

I also have the Zeda 80...the first thing to do is order this spring actuated tensioner,

Deluxe Spring Loaded Ball Bearing Chain Tensioner

Your source for 2-Stroke and 4-Stroke Bicycle Engine Kits, Performance Parts, and Accessories!

www.bicycle-engines.com

It also looks like you have the same 36 tooth sprocket that i also use.

Did you follow the ZEDA 80 instructions EXACTLY when you attached it to the rag joint...This is important to be sure you do not have sprocket "wobble" that could have contributed to your problems in the first place???.

Are you changing out the sprocket because it also was damaged???.

You need to use a chain breaker and shorten that chain A.S.A.P....Replace the chain if you feel it was twisted or damaged in any way whatsoever.
That chain should never have been allowed to have that much slack.

By the way, your "bucking bar" that you thought was a broken piece is just fine...I use just a dab of white lithium on both ends of it for lubrication for less wear since it is pushing against what passes for a clutch throw-out bearing.

Last and not least, when you put the new spring loaded chain tensioner on this, be sure to locate it so it has a fairly tight fit on the chain, The spring actuator will do the rest for self adjusting puposes once you have cut the chain down to a manageable length...it should never be touching itself, The same as most moms told us kids growing up...lol...i mount the tensioner on a piece of old tire innertube for grip and really, really tighten the crap out of it in equal portions on both top and bottom bolts/nuts, but being very careful to NOT crimp the metal tubing that your mounting to...DAMIEN

In over 5 years and at present time over 6600 miles, i have never once had any problem with the entire drive train by following these proceedures.

The 5 years before that was my learning and mistakes period...lol.

Pics below are my most recent finished product as of May 21st 2020...i am at 600 miles on this build since May, as of today with zero problems.

 

[Chainlube]

Try to take out a link, the chain should never be that close. The keeper for your master link needs to be turned around, it always enters from the direction of chain travel.

 

[Jprice1707]

I also have the Zeda 80...the first thing to do is order this spring actuated tensioner,

Deluxe Spring Loaded Ball Bearing Chain Tensioner

Your source for 2-Stroke and 4-Stroke Bicycle Engine Kits, Performance Parts, and Accessories!

www.bicycle-engines.com

It also looks like you have the same 36 tooth sprocket that i also use.

Did you follow the ZEDA 80 instructions EXACTLY when you attached it to the rag joint...This is important to be sure you do not have sprocket "wobble" that could have contributed to your problems in the first place???.

Are you changing out the sprocket because it also was damaged???.

You need to use a chain breaker and shorten that chain A.S.A.P....Replace the chain if you feel it was twisted or damaged in any way whatsoever.
That chain should never have been allowed to have that much slack.

By the way, your "bucking bar" that you thought was a broken piece is just fine...I use just a dab of white lithium on both ends of it for lubrication for less wear since it is pushing against what passes for a clutch throw-out bearing.

Last and not least, when you put the new spring loaded chain tensioner on this, be sure to locate it so it has a fairly tight fit on the chain, The spring actuator will do the rest for self adjusting puposes once you have cut the chain down to a manageable length...it should never be touching itself, The same as most moms told us kids growing up...lol...i mount the tensioner on a piece of old tire innertube for grip and really, really tighten the crap out of it in equal portions on both top and bottom bolts/nuts, but being very careful to NOT crimp the metal tubing that your mounting to...DAMIEN

Pics below are my finished product.

I'll order the spring loaded tensioner like you mentioned. I've heard that they are a lot more reliable. And I'll definitely shorten the chain as well. You're correct, it's the 36 tooth sprocket.

I did follow the instructions, but I think when I replaced the rear tire/rim I didn't install the sprocket correctly. Lesson learned.

I'm buying a new sprocket because I can tell some of the teeth are bent. I was thinking about going up in teeth (41 or 44) so I can go up hills a little better. I've done research on sprocket sizes and more teeth, more bottom end? I have to peddle a good bit when going up hills and I'd like something that pulls me up hills better but then again that top end on the 36 tooth, oh man! Is it fun. Haha. I didn't want to lose that.

Your bike looks awesome!

 

[Jprice1707]

Try to take out a link, the chain should never be that close. The keeper for your master link needs to be turned around, it always enters from the direction of chain travel.

Thanks, I'll fix that

 

[DAMIEN1307]

Thanks, I'll fix that

I took out multiple links with my 36 tooth, i can also tell you that I live at a 4500 ft altitude and ride as high as 9000 ft sometimes.

With the 36 tooth, im going up some good size hills at 32 MPH steady and can achieve 50 MPH on the flats. (not recommended on a bicycle unless you enjoy cleaning racing stripes out of your underwear...lol).

The only changes i made from stock was using the spring adjuster which of course would have no real bearing on this but also changed the stock NT carbie air filter to the link im providing below and tinkered with the needle valve to its leanest setting due to altitude.

Air Filter - Low Profile Chrome

Motorized bicycle, motor bike, electric bike, ebike, pedal assist

sickbikeparts.com

Otherwise this is stock.

 

[Jprice1707]

Did you keep your exhaust stock as well? I was looking at purchasing this if it was worth it.

Zeda 88 Performance Exhaust Pipe Chrome Muffler (MZ65 Replica) For 2 Stroke Motorized Bicycle Engines

Your source for 2-Stroke and 4-Stroke Bicycle Engine Kits, Performance Parts, and Accessories!

www.bicycle-engines.com

 

[DAMIEN1307]

Did you keep your exhaust stock as well? I was looking at purchasing this if it was worth it.

My exhaust IS stock...DAMIEN