Chain Tension Help! Tense vs Loose the debate rages

[Bettleguise]

Ok every chain has a tight spot. But if it's too loose it rattles around, makes a bunch of noise and can fall off. If it's too tight it makes a grinding noise, you feel the friction when you pedal, but it doesn't rattle.

So to fix this i made a a couple chain guides on the inside of the guard to keep the chain in one place. I put some rubber and felt anywhere the chain might hit including the fender. It helped some, but I realized that a lot of the rattling was coming from the chain bouncing on the rear cog.

an eraser, trimmed and glued to the chain guard and rubber bungee/felt combo onto

I made a little hook/hanger that does an ok job. Then made a chain tensioner out of a derailleur cage. Seemed like a good idea, but it makes tons of noise, like a bike stuck between gears. Also I think tensioners are for single speeds with free wheel. I don't know how well the work with a coaster brake. The force against it when you brake seems to push it out of place.

I know you guys must have come up with a couple tricks to keep the chain running quiet and smooth. Guides, sleeves, tensioners ect. Post some pics if you built anything like this. Also what's up with the tight spot/ loose spot of a chain? Obviously the chain ring, cog and crank could cause it, but if everything is new, doesn't the chain still have a tight spot? Can you whack the front chain ring with a hammer to even out the chain tension?

 

[user 135]

I have never had too much problem. Most often the chain ring is not perfectly round, so a hammer will not help out.

Maybe try a different cog in the rear or sprocket up front. A chain tensioner will just cause problems.

 

[deorman]

Aside from any manufacturing imperfections, the front ring is not a press-fit part, so loading can cause the ring to shift to the side. Mine seem to always have the tight spot in the same place. I just pull it snug (not super tight) on the tight spot, if you snug it on the low it will bind, and not only make noise, it also wears things out. I've never had one bad enough to have a noticeable effect while riding. It sounds to me like your rear cog may be shot, it might have been used for an extended time with a "stretched" (worn out) chain. :|

 

[JoKeR63]

Since I ride recumbents I'm well versed with chain tubes, they sure can reduce a lot of floppin' around. But I don't know how well it would work inside a chainguard, you'd have to experiment. Go to any place they sell plumbing supplies and look for 1/2" ID white water supply tube. It's a slippery plastic and it's CHEAP, might be worth a try. I use it to manage the chain on this beast, this particular set-up is self tensioning.

Keep in mind you have to anchor it, or it will go into the sprocket!

 

[Bettleguise]

That's an idea. I knew you recumbent and stretched out burrito riding guys would have some innovations here. Does that chain tube make much noise? Anyone out there use some kind of roller device to keep the chain in place, kinda like what you seen on a trials mountain bike? I want my bike to be silent over the bumps, NYC is a modern city with third world roads and corrupt mobbed up paving contractors.

 

[icyuod2]

this was punked from an old moped (spring loaded)

you could fashion one from an old derailer
never had to use one on a factory bike. fine tuning is usually all they need to keep noise/friction to a minimum.

 

[JoKeR63]

That's an idea. I knew you recumbent and stretched out burrito riding guys would have some innovations here. Does that chain tube make much noise? Anyone out there use some kind of roller device to keep the chain in place, kinda like what you seen on a trials mountain bike? I want my bike to be silent over the bumps, NYC is a modern city with third world roads and corrupt mobbed up paving contractors.

One thing about chain tubes is that they quiet down considerably after they break in. They'll wear in grooves that the sideplates ride in. You also have to flare the ends out as well. Rollers are almost always noisy. I've heard that the Terracycle idlers are supposed to be quiet, but they're $50 U.S. each, ouch!