Chain lock up did something unexpected

fast3fifty

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Joined
Feb 7, 2022
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2
Most everyone who rides a motorized bicycle has experienced their chain locking up in the upper portion of the engine block and the top of the drive gear, I myself have more than once, but the last time it happened, (a couple of weeks ago), the chain actually locked up from getting wedged between the drive gear and the front of said gear, breaking or busting the wall if you will, that seperates the magneto and drive gear, shrapnel ended up going into my magneto Wich actually caused the engine to instantly sieze up an stop running, after walking it two miles back home, I was able to see what exactly happened and was able to clean out the debris and get it running again, I was not expecting to see this, and was just wondering if another has heard of this, or has had it happen? Thanks for any and all responses.
 

Cisco

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Joined
Jun 9, 2021
Messages
592

Pro Taper Gold Series PT415MX Chain (120 Link)

Usually sold for around $35 (fairly reasonable). Are 120 links enough for most bicycle applications? I don't really want to count the links on my bike (would probably a good thing to know). The product description recommends using MX chain lube only. Any special reason why? Choice between sealed and unsealed? The more I learn the less I know :-\
 

Karl Snarl

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Sep 20, 2019
Messages
5,691
Seems like the only source for this chain on Ebay is the UK?
Not sure, been a while since I needed any. Stuff last forever on our bikes. After initial stretch in, it doesn't stretch anymore. That lit chain just keeps stretching like taffy. RK is awesome chain, I believe it's Japanese.
 

Karl Snarl

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Joined
Sep 20, 2019
Messages
5,691

Pro Taper Gold Series PT415MX Chain (120 Link)

Usually sold for around $35 (fairly reasonable). Are 120 links enough for most bicycle applications? I don't really want to count the links on my bike (would probably a good thing to know). The product description recommends using MX chain lube only. Any special reason why? Choice between sealed and unsealed? The more I learn the less I know :-\
120 will get most chains made. I usually have to 100-105 links with a 44 tooth.
 

Karl Snarl

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Joined
Sep 20, 2019
Messages
5,691

Pro Taper Gold Series PT415MX Chain (120 Link)

Usually sold for around $35 (fairly reasonable). Are 120 links enough for most bicycle applications? I don't really want to count the links on my bike (would probably a good thing to know). The product description recommends using MX chain lube only. Any special reason why? Choice between sealed and unsealed? The more I learn the less I know :-\
Sealed is harder to clean. I stay away from oring chain because of that. Not to mention the oring increases power losses. Just take a bunch of old candles and melt the wax. Did a clean degreased chain in it. Swirl it around a bit to get the wax to push out any air. Hang it up to dry for an hour. Your chain is ready for thrashing. Just install and let the excess fall off.
 

inspectorcritic

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Joined
Dec 13, 2015
Messages
1,905
Me I am having new issues with that must be a catchy disease.
A somewhat solution instead of just popping the clutch just release it gradually while pedaling you don't get the big jerk of start-up and gives the tension some time to smooth out.
 

fast3fifty

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Joined
Feb 7, 2022
Messages
2
I actually run two chain tensioners, the original that mounts to the lower chain stay, running a self tapping screw through it and into the frame once it's in it's desired location, so as to keep it from going into the spokes, and the one with the spring and flat plate that bolts to the outside of the drive gear cover, have never had any problems starting, well after the first chain lock up lol, this time I was rolling along down the road, when it locked, at the front side of the drive gear, instead of the usual topside, and destroyed the thin wall that seperates said drive gear, and the magneto.
And I was really just wondering if this has happened to another at anytime? I'm just happy I was able to get her up and running again in a short time, felt lucky, but that doesn't always last too long, lol.
 

yuckfoo

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Joined
Nov 21, 2020
Messages
728
I had this problem too. I took my dremel to the case and cut that area out. My suggestion for all new builds is to mark the inside with paint or marker then take the bike out, hold in the clutch and pedal it. The moving chain will rub away the marker and you'll be able to see where you need to file or grind away material.

 
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