Chain Slack on Fixie?
 

Hello people. I have to ask for your opinion as to whether my chain seems to be too slack. The pedal has a little bit of lag. Here is a picture of how the current chain tension is.

Edit: sorry if I posted this in the wrong section.

Looks ride-able to this geezer.

Looks good to me.

Thank you 50voltphantom and TejanoTrackie. It's been a bit frustrating b/c after 40 miles each week, the chain tension changes a bit and becomes a bit more slack. I don't know if it should actually be that frequent.

Check yer bolts.

As in check for tightness?

Yes. It's common for a wheel to creep forward as you ride. Don't try to remedy it by using gorilla-like strength when tightening your axle nuts (which will damage your axle hardware, bearing cones and bearings). Instead, simply re-tension your chain from time to time.

The tension you want is one that 1) has preferably no more than ~1/2" of play in the top with the bottom tight and (far more important) 2) never goes tight as you spin the crank for enough revolutions to get the every combination of crank orientation and wheel orientation. This is because neither cogs not chainrings are concentric. Both have machine tolerances. Better quality stuff is better, parts made fro the track better still in general and the best track parts are very good, but still not perfect. The most important aspect of chain tension is that too much, ie a tight chain puts a huge load on your bottom bracket and hub bearings and will shorten their life dramatically. Too loose simply means that you may drop the chain on bumpy roads. Now, if you choose to ride without brakes in hills on cheap drivetrains, it could be argued that killing bearings is cheaper than throwing chains on steep hills. (I'm too old to be making those choices.)

Ben

A chain that is too tight will bind, acting like a brake. You want your chain as loose as possible without it being able to come off (this is where it is most efficient, and the drivetrain is least stressed). Trackies check this by picking up the bike, giving the cranks a (slow)spin, and trying to derail the chain with a wrench (or other suitable tool). If the chain can't be pushed off, it won't "bounce" off the ring while riding.

Chains that are too tight will break.

Hmmm, I wonder if "The pedal has a little bit of lag" the OP is talking about is a loose cog and lock ring?

Nuts :)

Gah, I'm embarrassed.

They aren't merely different, they are the exact opposite. You get double time in the Time Out chair for that one.

Chain looks ok to me. From what I've read, and been told, and what I usually do is check the chain after tightening it. There should be about a 5 - 10mm of flex when pushing down on the chain, midway between the cog and chainring, at the tightest place. Or tight enough but not so tight as to bind the chain. You can test by rotating the crank and trying to "throw" the chain with a wrench.

You'll find that, with most chainrings & cogs, your chain will be tighter in some places, and looser in others. I try to strike a balance between these two extremes, while erring on the tighter rather than the looser.

Besides, sometimes a little looser is better. It makes track standing easier :)

Flip the bike over and bounce the head of your box wrench on the chain halfway between the chainring and the cog. It's too tight if you can hear or feel a rumble in the chain. It's too loose if the bounce gets sloppy. Over time you will come to learn what the bounce in the sweet spot feels like. Using a chain tensioner allows you to dial in that perfect "pitch," then tighten up your lug nuts. Good luck.

How can I tell if my shoes are tied too loose? I tried hitting them with a wrench to no avail.

That's because you have to try to PUSH them off with the wrench. Sideways. In the direction they're travelling.

Try a larger wrench....

Hold your bike over your head and shake it. If the chain falls off, it's too loose. If you drop the bike on your head, you're not strong enough to ride fixed gear. If you follow this advice, you're too stupid to ride fixed gear.

Instead of making a brand new thread I'll piggyback on this one.

I just picked up a used fixed gear and this is my first bike with vertical drop outs. While adjusting the chain tension tonight, I noticed this odd plate with a twist screw on the drivetrain side. It's a plate that sits over the axle and the axle nut tightens against the side of the plate sandwiching it against the frame. On the back of the plate is a wing nut bolt that's supposed to keep the hub from shifting.

Should I trash this plate or do they actually work? Seems a bit dodgy.

It's a chain tensioner. I've never used one in my life and I'm okay.

These damn shoes, though...

This is why I have velcro shoes and bikes with derailleurs.

No need to deal with life's two most difficult issues.

But don't you know gears constantly go out of adjustment and it takes a Phd to turn a barrel adjuster.

A chain tensioner makes it easier to get the tension you want and will allow you to keep it longer than just relying on your track nuts to hold the axle in position. If you don't mind the little bit of extra weight, they're worth having.

I strongly disagree. I find chain tensioners to be more of a pain in the ass than anything else. Whenever a customer comes in to have a flat changed and they have tensioners on their bike, it makes me scream inside.

Centering a wheel and keeping proper chain tension using axle nuts isn't exactly rocket science.