Chain size chart

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2door

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Staff member
Sep 15, 2008
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Littleton, Colorado
Still running the chain i salvaged off an old garage door opener. That stuff is tough.
Here is a man who knows how to align and tension roller chain.
Thanks TJ.

Greg is another one. Set up right, aligned, lubricated and the tension correct there is no reason for chain probelms.
It isn't rocket science, just common mechanical sense. The chain must be aligned with the sprokets and kept at the proper tension. They'll give you miles and miles of trouble free service.

Thanks guys.

Tom
 
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SlowMoShadow

New Member
Feb 11, 2015
2
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pueblo co.
I have a 49cc 2 stroke 20t front sprocket 44t rear . #25h chain how fast should it go what mpg can I expect this is my first build. Should I get a bigger chain was thinking #35 any help?
 

Greg58

Well-Known Member
May 1, 2011
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Newnan,Georgia
Welcome to the forum, standard chain is #410 the upgrade chain is #415, you can also use #41 which is what I use. I have broke both of the former chain but never have broke the #41. 41 is the widest of the three, some people have had clearance problems under the cover but I haven't had any.
 

Chainreaction

New Member
Dec 14, 2014
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Tulsa OK
I am using #35 chain (except for crank to derailer), smaller 3/8's pitch mean smaller sprockets and less weight. More available sprockets. Seems like win/win.
 

maniac57

Old, Fat, and still faster than you
Oct 8, 2011
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memphis Tn
I'm with 2door on chains.
#41 industrial is going to outlast practically everything on your bike but the frame.
And it's easy to grind the needed clearance under the sprocket cover.
It's like a bulldozer part bolted on an ultralight.
 
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indian22

Well-Known Member
Dec 31, 2014
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Has anyone had experience with the #420 chain? The chart shows it to be much stronger than the 41 & all dimensions the same except for being 1/16" wider between the plates. I wouldn't be using on a China girl but rather a Honda125cc so chain to case clearence is not a factor.I'd like to use a Manic style hub adaptor and Manic 48t sprocket, all mounted on a coaster brake hub (110)...I'm running a wide rear triangle so I've got quite a bit of room to work with. Comments appreciated.
 

Jonda500

Member
May 10, 2014
86
8
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Canberra, Australia
I have 420 chain on most of my 6 m/b's- the rollers have a tendancy to shatter (twice I've had 420 rollers fail!) and they look crappy and have alot of side to side play. I like the look of the 415 chain a lot more because the plates are thicker and the rollers are nice symmetrical cylinders that dont have excessive side to side play; and because the width between the plates is narrower wich matches the thickness of the sprockets better, but, most of my chinese output sprockets wont work with the 415 chain (seems like the gear teeth are too long? maybe I could modify the teeth but easier just to buy new engine sprockets!)

edit- my 420 chain looks just like 2doors 415 chain in quality but is wider, and my 415 chain is narrow like 2doors but has bigger thicker plates and better rollers
 
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Greg58

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May 1, 2011
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I haven't had any problems with any of the bikes I've built using the wider #41 chain, a lot of the better quality kits come with the 415. The only problems I've heard of was the chain rubbing the inside of the sprocket cover which is easy to repair.
 

Jonda500

Member
May 10, 2014
86
8
8
Canberra, Australia
I can't see tilting the engine helping at all.
You have found the same frustrating chain/sprocket compatibility issue that I have struggled with big time! Ideally, if you buy an engine sprocket with more pointy teeth, it could solve your issue but you wouldn't know for sure until it arrived - a more surefire fix would be to buy a 420 motorized bicycle chain (but I hate these dodgey looser fit chains!) N.B. Your chains/sprocket/results may differ from mine!
John
 
Jan 21, 2015
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Portland, Oregon
I use a #420 chain ever since my #415 catastrophically failed one day while I was in the middle of a highway in heavy traffic with a 45mph speed limit and almost got hit by a car. I have not had any problems with the #420. It looks to be stronger than the #415, and it fits the chinagirl engines as well.
 
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javy mcdees

Active Member
Jul 30, 2018
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I just put a 420 chain on mine cause the 415H chains do not last very long, the 420 chain seems to work just fine for me but only have a few hundred miles so far on it now. Yesterday my chain tesioner spring fell off but the chain was fine for 20 miles until I was able to fix it.
20190603_123250.jpg
 
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EZL

Well-Known Member
May 13, 2016
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Chenoa, Illinois, USA
I just put a 420 chain on mine cause the 415H chains do not last very long, the 420 chain seems to work just fine for me but only have a few hundred miles so far on it now. Yesterday my chain tesioner spring fell off but the chain was fine for 20 miles until I was able to fix it. View attachment 101081
I tried a lot of the different chain tensioners and even built one of my own. I don't like the idea of clamping to the lower tube
on the bike. I've had better luck with "Arch Chain Tensioner" since they help support two of the back tubes on the bike.
GasBike, Kings Motorized Bikes and MBRebel has them along with a few dealers posted on the Forum. Here's what
they look like off of MBRebel's site:
 

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EZL

Well-Known Member
May 13, 2016
349
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Chenoa, Illinois, USA
A 40 is way too wide, the 41 works good. I’ve been using the same 41 on my black bike for 8 years
Greg, I have the industrial grade 41 on my little 49cc 4-stroke and haven't had any problems with stretching like
I did with the 415 and now my other bike with the 212cc broke the 415 chain the other day. I want' to check on
the 420 or 42 industrial chain to see if it's available at a farm store.
 
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EZL

Well-Known Member
May 13, 2016
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Chenoa, Illinois, USA
Has anyone had experience with the #420 chain? The chart shows it to be much stronger than the 41 & all dimensions the same except for being 1/16" wider between the plates. I wouldn't be using on a China girl but rather a Honda125cc so chain to case clearence is not a factor.I'd like to use a Manic style hub adaptor and Manic 48t sprocket, all mounted on a coaster brake hub (110)...I'm running a wide rear triangle so I've got quite a bit of room to work with. Comments appreciated.
The ManicMechanic sprockets will work on the 415 and the 41. The chainset sent with the kits I really have problems with.
I went to the farm store and got a 10 ft. long "DID 41" chain made by Daido Kogyo Co., Japan. A big difference in
quality from the 415 kit chains. I suspect the 415 kit chains are made of low grade steel. Why I say this? When you have
problems grinding down a pin on the grinder and then trying to bend the side link away from the roller, told me. I bent the
chain breaker's pin trying to separate a link on the 41 chain and it worked ok on the 415.
 
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Greg58

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May 1, 2011
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The #41 chain is hard to beat, I got mine from the local tractor supply, It’s enough for two chains if you buy extra master links.
 
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EZL

Well-Known Member
May 13, 2016
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Chenoa, Illinois, USA
I thought this chart may help some new to M/b building to select a better chain.
Chain Strength & Dimensions

Chain Number Pitch Roller Diameter Betwwen Inner Plates Pin Diameter Average Tensile Lbs. per foot
__#40 (#425) 1/2 .312 5/16 .156 3,700 .41
__#41 1/2 .306 1/4 .141 2,000 .27
__#410 (#43) 1/2 .306 1/8 .141 1,600 .19
__#415 (#42) 1/2 .306 3/16 .141 1,600 .26
__#415H (#42H) 1/2 .306 3/16 .141 1,600 .26
__#420 1/2 .306 1/4 .156 3,700 .38
__#425 (#40) 1/2 .312 5/16 .156 3,700 .41
__#428 1/2 .335 5/16 .177 4,200 .44
__#428H 1/2 .335 5/16 .177 4,200 .44
__#520 5/8 .400 1/4 .200 6,100 .64
__#520H 5/8 .400 1/4 .200 6,100 .68
__#520-2 5/8 .400 1/4 .200 12,200 1.26
__#525 5/8 .400 5/16 .200 6,100 .65
__#530 (50) 5/8 .400 3/8 .200 6,100 .66


note the 410, 415, 415h all have the same tensile lbs. #41 is stronger.
Thanks Greg for the chart! Hard to believe that the lower number on the chain was stronger. I noticed the
difference when I tried to push a pin out with a chainbreaker. I couldn't push it out and even bent the
pin on the chainbreaker. Never had any problems with the 415 in removing links. I did end up getting
another chainbreaker and have retired the old one to breaking bicycle chains.
 
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