there's a bit of an unwritten rule that if you're riding brakeless you should be riding 1/8". why is that? does anyone have any horror stories about 3/32"? I have a stack of 3/32" chainrings I'm itching to use.

where'd you hear that rule?
you have to be some kind of monstrous human break drivetrain parts, even 3/32" parts.

i rode 3/32" brakeless for a while (i live in sf) with no problems.

if you're under 200 lbs. i don't think you'll have a problem.

caveat: i weigh 135 and am not especially strong

I can't tell you where I heard it because I forget.

I guess the logic follows if you're riding brakeless, you don't want your drivetrain to fail, so you go with the strongest out there.

but I agree that you would have to be a monster to break something. something my 155 lbs ain't.

so why "i rode 3/32" brakeless"? and not "i ride 3/32" brakeless"?

i ride

'cause i have rebuilt knees and the cool factor isn't worth the risk of destroying them again.

i rarely use the brake, but i like having the option.

Not really. I've done it. Unless not paying attention to rust/wear/stiff links makes you a monster... Okay, I used to be a monster.
I had brakes when I broke my 3/32 chain, but I try to only use 1/8 now. Why? I don't know - it just looks better and feels better. Seems like power transfer is better, too. I think the teeth on the cogs and chainring wear better and are less likely to get bent, too.

I was actually eyeballing a 3/16 chain in the LBS the other day, until I realized I'd have to spend a bunch more money to get a chain tool that would work with it... And probably buy two chains to get enough length to run a road gearing instead of a BMX one.

gotcha. I thought maybe the 1/8" fairy whispered in your ear and made you switch.

3/32 on front, 1/8 on back...everything's still there

3/32 and brakeless

The measurement refers to the width of the links correct? So basically the width of the little posts that hold the link 'panels'. So I would even think that the 3/32 is stronger than the 1/8 just because for example it is much easier to break a long stick then a short one. Unless I've got this thing all wrong.

Doesn't make any sense to me. Look at it this way, on a MTB with a 22 tooth granny and 175 mm cranks, a 200 lb rider is going to produce 700 lb of tension on the chain while climbing. Those chains don't break much, if ever. You will not be able to come anywhere close to that chain load with typical fixie gearing. A wider chain may be a better choice, but the narrow is more than strong enough.

meh, I run a 1/8 chain on 3/16 gears. Strange, but true.

all of my fixies are brakeless and have 1/8 chains, but on two of them i have 3/32 chainrings.

well here is the word from Sheldon Brown

1/8" or 3/32" Chain?

Many track bicycles use a wider chain than is common on multi-speed bicycles. Derailer-type chain has a nominal internal width of 3/32". Single-speed bicycles, including most track bicycles, use the wider 1/8" size. You can buy fixed-gear sprockets in both sizes.

(Some people mistakenly refer to the width as "pitch", speaking of "road pitch" or "track pitch". This is a malapropism. The pitch is the distance between the rollers, and all modern bicycle chain has the same pitch, 1/2"/12.7 mm.)

I would generally advise using the 3/32" (derailer) size. It is lighter, more compatible with your existing chainwheels, and likely to run smoother if the chainline is less than perfect, due to beveled side plates. In my experience, 3/32" chain is no less durable or reliable than 1/8".
For the true retro fan, another option is 1" x 3/16" chain. This used to be common on track bikes. This requires special sprockets with only half as many teeth as standard 1/2" pitch sprockets. Serious old-time trackies used "block" chain, which had no rollers. This is no longer available. Roller chain is still sometimes findable in this size.

Even more obscure is the 10 mm pitch chain promoted by Shimano a few years back. The idea was to save weight by making everything littler. An idea whose time never came.

The "strength" of the chain is determined by the thickness of the side plates and the diameter of the pins, right? So why would 1/8 be any stronger?

Isn't the only difference between 1/8 and 3/32 the length of the pins?

Been doing it for over a year without issue. I don't really buy into the 1/8 is stronger thing.

I ride 3/32 brakeless and haven't had any problems. If you're really worried about breaking your chain, I suggest the Kink BMX chain:



I used to ride these on my BMX bike. It survived many a feeble grind gone wrong to chain grind.

There is no fundamental reason why a wider chain would be stronger, all else being equal. The 'easier to break a long stick' argument is apt. Plus, 3/32" has been developed more, and often includes more technological goodies like beveled plates and bushingless designs (which are usually regarded as just as strong, and smoother than bushings).

MTBers have been putting ludicrous amounts of torque on their chains with no problem, and you won't have that problem either.

The only reason I'd go 1/8" chain is for retro goodness, or if that was the only cogs and rings I had around. Nothing wrong with retro goodness, just in this case realize that it isn't a decision based on durability.

The one durability concern I hear about a lot (and not just in the fixie world) is breaking master-links. Masterlinks are great if you aren't putting much torque on your chain, or for making a quick fix on the road, but if you are riding brakeless, I'd invest in a good chaintool and install your chain the right way. If you ask around about chain breakage horror stories, 9 times out of 10 it was a master link that failed.

peace,
sam

Actually, 9 times out of 10 (ok, that's not really a scientific poll, but let's just put it at most times) I hear of, it's a Shimano 9-speed chain coming apart at a link pin.

I've used a 3/32" for a little over 2 years now. I've only had one chain break (a SRAM, I didn't use the masterlink). Since then, I've used Shimano 8spd chains with their pushpins.

Now, the more that I think about it - I should have used the masterlink on that SRAM - you're never putting backpressure on the link - so there's no reason to think that it would come apart - your chain is always tensioned - even during backpedalling.

My friend runs one - he just finished a tour on his fixie from here to Florida - no problems, and he has had it on his bike for a good while before this tour too.

I have broken 1/8" chains on my pedicab - 4 in the last six months. Nothing is unbreakable.

Installation Error. I would bet that 8+ of these failures are due to improper installation, reusing pins, or not using the special shimano pin.
Shimano is one of the harder chains to install, cheapo KMC or SRAM chains are much easier, and some have the powerlink dealie....

I agree mr. dark mother. People have been spouting nonsense like '1/8" is stronger', 3/32" can't withstand the forces that track riding puts on a chain'.
If you look at the math, your 100# girlfriend spinning in the granny gear on her hybrid will ALWAYS put more force on the chain than you can, any day of the week.....

And be sure to tell her that. She will feel all hardcore and stuff.

....yeah, thats why bmx chains (usually 1/8) are available in "hardcore" versions with thicker side plates.

Personally, I will take Sheldon Brown's word for it (and most if you too). I ride 1/8" Track, but I can't see how a bike that rides 21days through the Tour de France has a weaker chain than my Wipperman Track Chain.

That being said there are some road chains that you need to avoid when riding fixed. Some of the cheaper road chains have weird master links that if you put back pressure on, will actually pop. I believe TAYA may have a chain that does this, but I am sure it is not the only one.

Cheers
Rob