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Discussion Starter #1
I searched the threads about chain tensioners, and saw some neat setups, but I have kinda a unique situation. O, and I'm talking about a rear chain tensioner for an aftermarket rigid big twin frame.

I have a spot on the lower part of my frame that the chain hits from slack and it wears a mark that I end up welding every year. It's thick wall, and it's just barely past the paint, but I don't like the idea of any frame damage minor or not.

So I really don't need a "tensioner" so to speak, I just need something for the chain to ride on instead of the frame. So I'm thinking of just comming right off the frame with a tab (the frame doglegs in the area that gets rubbed) and adding a skate wheel for the chain to ride on. Now for this setup, it doesn't seem to require a spring. Everything i saw in the chain tension threads had springs.

Am I missing something or can I run the skate wheel with no spring loaded acttion?

Thanks for any input

Sixball
 

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I wouldnt see why not.Just have to be a little more diligent about keeping chain tension.The one I made doesnt have a spring.
 

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I had the same problem with my Triumph, I run a nylon wheel solid mounted
at a point where if the chain is under tension at the bottom it just touches.
That way when you button off it has very little stress on it.
It stopped the chain slap on the frame.
 

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Discussion Starter #6
I had already checked out Monstercraftsman, and also Troy Fab, I'll look into the mountain bike deal as well. Where my rubbing is, is in a dogleg, so the bracket might look funky. Is there anything else used for frame rub from a chain? Maybe some kind of heavy duty NASA plastic BS, that you can apply to the frame?

Sixball
 

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well on my custom monark i used the timing chain tensioner shoe from a small car engine and still works and not worn down either,tensioned just with a spring similar to thoose found on a clothespin (right word??) and that is mounted to the same pivot arm as the shoe so it's very compact :)
 

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well on my custom monark i used the timing chain tensioner shoe from a small car engine and still works and not worn down either,tensioned just with a spring similar to thoose found on a clothespin (right word??) and that is mounted to the same pivot arm as the shoe so it's very compact :)
I was wondering about something like this also you have any pics
Ryanm
 

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A lot of dirtbikes use either a fixed wheel of some type of nylon slide. I have a KTM that has a fixed roller on to top side of the chain to limit travel. Can you just put a semi circle shaped piece of nylon over the frame? If it is only making contact part of the time, probably all you will need.
 

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UHMW (ultra high molecular weight polyethylene)

I've used a skate wheel with no spring and it works fine. I've also used different types of plastics just to keep the chain from marring up the frame. Some is softer than others and needs replaced as it wears.

If you have a local plastics company tell them what you're using it for and they might give you a scrap piece of nylon or something. Cut it to the shape you need and countersink some bolts. That would be a lot cleaner looking than a skateboard wheel.

http://www.usplastic.com/catalog/item.aspx?sku=48555

 

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SYF nailed it! Ask for a scrap of UHMW or delrin. It's available in black but you'll likely get white for free.

In fact, I've got a 5" x .250 strip in my hand if you can use white. I could whack off a couple inches and drop it in the mail if it helps:cool:

GT6Steve AT AOL DOT Com
 

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I was wondering about something like this also you have any pics
Ryanm
i'll try and make it to the storage space and snap some tomorrow,i'm painting cars tomorrow so not to much time :)
 

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Whoaa painting.. set some time aside always takes longer than expected.. haa
so true it's not even funny :D
but 06:30 i went over the ugly thing with the tack cloth and started painting so early morning does the trick

found this pic see if i can get a more detailed one later

 

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Have a look at modern dirt bikes. my 09 WR250F has a rubber style guide on the swing arm. I'm 3000km from it at the moment so cant take a pic sorry.
 

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I have a early sportster, that I ran a square tank on, and the chain would eventually hit the bottom of the tank, if not kept perfectly adjusted. So I fabbed a mount to weld to the down tube, and purchased a complete BT primary chain assembly. Mine was for the upper side of the chain, and it is not set to hold chain down, but to keep the lash from rising and hitting the tank. Plus, it is adjustable, if necessary. Something similar would work on your problem, and if it ever wears out, easily replaced with stock stuff. I don't have any good photos, but could get one if you wanted to see it.
 
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