chain tension

GoldenMotor.com

glenz

New Member
Jul 23, 2009
26
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0
montana
a constant prob. i have is the cheap- #$%@&%$$#!!??-chinese chain tensioners.anybody come up with a better way?-thanx-G.Z.
 

2door

Moderator
Staff member
Sep 15, 2008
16,302
175
63
Littleton, Colorado
Glenz,
How handy are you? Do you weld or have access to a welder or a friend who does?
Personally I have three bikes, one has over 1500 miles on the kit chain tensioner with no problems. The tensioner needs to be secured to the chain stay so it can not rotate into the rear spokes and the bracket given a slight twist to align the wheel with the chain correctly, but there are other alternatives. Here are two views of two different approaches to the tensioner issue.
 

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Aug 23, 2009
379
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0
British Columbia
Hello, I like your tensioner ideas. The second one is awesome! My tensioner stripped somehow WHILE I was riding, and loosened the chain a whole lot, which made it hit inside the casing, and snapped one side of my #41 chain!!!! I'm a cursed rider who has a break down EVERY time I ride. I've had everything go wrong, including a snapped frame. I can't begin to express my frustrations, and I literally want to give up on motor bikes. Here's my question, can I use a rear derailler from another bike as a chain tensioner with a #41 chain? And how would I do that? If you can help, that would be excellent, I need this repaired AGAIN asap. Thank you.
 

Bmetz

New Member
Sep 21, 2009
21
0
0
Indiana
try the chain tensioner and spring from tractor supply mention in other posts, i used the cheap chinese bracket with new automotive bolts and lots of thread lock, works well now.

to keep the tensioner wheel from sliding down in the slot i added a extra bolt in the slot as a block.

also used some teflon tape where the tensioner turns on the bolt.
 

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Bmetz

New Member
Sep 21, 2009
21
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0
Indiana
thats a good idea drilling a hole to keep it from turning. mine got loose a couple of times till i switched to automotive grade bolts and used thread lock where the metal clamps to the frame. i was worried about weakening the frame by welding a cross piece
 

2door

Moderator
Staff member
Sep 15, 2008
16,302
175
63
Littleton, Colorado
thats a good idea drilling a hole to keep it from turning. mine got loose a couple of times till i switched to automotive grade bolts and used thread lock where the metal clamps to the frame. i was worried about weakening the frame by welding a cross piece
Welding to the frame, if done correctly by a competent welder will not weaken, but will strengthen the frame. Underline "correctly" here. A bad weld can be a weak area and if the base metal, the frame, is not incorporated into the weld it can fail at that point.
Tom
 

bairdco

a guy who makes cool bikes
Aug 18, 2009
6,537
264
63
living the dream in southern california
i, personally, would never drill a hole in my chainstay.

and i dunno if i'm just lucky, but all the bikes i've built haven't needed a tensioner. i've changed out the rear sprocket or front chainring on the pedal side, added or subtracted chain links, spaced out the wheels, and spent a lot of time figuring out exactly where to put the motor to keep a straight shot.

i realize that this won't work for all bikes, and if i ever need a chain tensioner, i'll probably try to modify something like this:
 

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soccerrj88

New Member
Sep 30, 2009
23
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0
Florida
Try this. Just took the stock Chinese POS and put it on the top chainstay, and put a 10" or so bar stock from tractor supply and extend it to reach the proper length and either drill a hole or make a slot for the wheel to slide up and down. You can even connect it at the end to the frame or I've noticed it works just fine without doing that...


brnot
 

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Junster

New Member
Jun 2, 2009
445
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Washington St.
You can also shim between rear motor mount and the seat post with some sheet aluminum to space the motor forward and eliminate the tensioner. You'd be suprized how much slack a 1/16" thick shim will take up.
 

skipu

Member
Aug 6, 2008
184
0
16
New jersey
your right takeitez but there are millions of bikes out there especially with motors on them im on my 26th build local guy by the beach ya know i ride every day wher bicycles are the only way to blow past all the tourist bull sh*t. out of 26 bikes i have used these tensioners on 20 of them thats a pretty good run i think and if you have the now how some slight modification may be the answer like rear motor mount and a little wider crank i have 2 milk crates of parts and that ive purchased plus over 20 bicycles that im slowly trying to consolidate into builds once you put a motor on a bike you are entering a black art form so to speak thats what makes it a hobby and i love it !!!!!!!!!!!!!!!
 

takeitez

New Member
Dec 19, 2011
139
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Clayton Missouri
That is an impressive amount of builds. I just suggested to search because there are a lot of other suggestions out there and no one had said so.