PimpMan

I want to convert to single speed setup is there any advantage of going with 3/32" (2.3mm) single speed chain vs keeping old 1/8" (3mm) derailleur chain?

e..g. Would single speed chain be lighter or less prone to getting clogged with dirt since it has less sideways play (chain pins has less gaps that can get stuffed with dirt)?

79pmooney

Traditional single speed chain - 1/8". Traditional (before 7/8, 9, 10 and 11-speed) derailleur chain - 3/32". 1/8" chains are heavier, have less sideways play and are less affected by dirt (or just about anything else. They can be run on on wider cogs that wear considerably better, improving chain life a lot.

One advantage of 3/32" chains is that they can be run over 3/32" rings and cogs from derailleur setups including 5 and 6 freewheels and double chainrings. 1/8" chains can run over the narrower rings and cogs, but not the freewheels and double cranksets. You can also go back and forth between single speed and derailleur use without changing chainrings.

3/32" single speed parts may be a little cheaper than the equivalent 1/8" but the 1/8" setup will last enough longer to be the cheaper down the road. It is a lot harder to throw off an 1/8" chain, especially running on 1/8" cog and ring, even after the chain is worn out.

I ran my fix gear 3/32" for 20 years. Switched over to 1/8" 20 years ago. I"ll never go back.

Ben

The only two things 3/32" chains do better than 1/8" chains: A little lighter and they shift far better. (The reason they exist.) Shifting is exactly what you never want your single speed to do.

Trevtassie

One of these, like a little motorcycle chain... https://www.bike-components.de/en/Co...-Chain-p24919/

caloso

I think the thinner chains are a bit more tolerant of a less than perfect chainline.

ThermionicScott 

I think you have your chains mixed up. The narrower 3/32" chain is used for derailleur bikes, and the wider (usually stiffer) 1/8" chain is what many of us prefer for fixed-gear/single-speed. 1/8" chain hasn't been used for derailleur bikes since the 1940s or so.

Jax Rhapsody

All I can add is; a single speed chain is probably stronger. Any kinda single speed drivetrain is going to apply more torque to the chain, than a geared one. The engagement is more direct. Put a 2/3 chain on a serious bmxers, track rider, or fixie riders bike and it'll eventually break.

Abe_Froman

I think the important thing though IMO is just match the width of your chain to the cog/chainring you have. Or replace everything with 1/8" if it isn't already..

JohnDThompson 

Using a 3/32" wide chain on a single speed limits you to using only 3/32" drive train components (cogs, chainrings). Using 1/8" wide chain allows you to mix & match 3/32" and 1/8" cogs and chainrings without problems.

IMO, that's the main advantage of using 1/8" chain on a single speed drivetrain. 1/8" chain may arguably be stronger, but 3/32" chain serves strong racers perfectly well so I don't accept that as a valid reason to prefer 1/8" chain.

Kimmo 

BMXers break their chains because they run them so tight they cause all sorts of carnage. Yuck

Doge

Yes. Also more newer advances go into them like PTFE coating etc.

Get a narrow/wide front ring.

colnago62

I have heard that a lot of track teams have gone to road chains for this reason. Probably enduros more then speed guys.

Doge

I don't think chain width is so much a factor in how strong a chain is. I have not seen hollow pin 1/8" chains. Solid pins could be stronger if the walls are too thin. We are talking 1/32 difference in distance, but a narrower chain is a shorter pin (tube) where in a 30% wider chain the pin may need to be solid. The plates make a difference. But some chains have the plates slotted. An 11 speed chain may require thinner plate than a track chain, but both seem plenty strong enough.

Chains I have seen "break" come from two things. The pin was over pressed in, or they get jammed on a shift and pried apart. The 2nd one required strong gear teeth, alloy cassettes will typically loose a tooth before prying a chain apart. I would think a pebble or screw sucked into the drive train on a BMX bike might spread things apart.
I don't spend a huge amount of time on the track, but really big torque guys are not breaking chains. I had many big team / torque miles on the tandem and no issues with a 10 sp chain.

colnago62

I do spend a lot of time at the track. I don’t see a lot of speed guys on narrow equipment. It might just be tradition. I do know the stress on equipment in a standing start is pretty high. Tandem riders aren’t starting from a dead stop in 104 plus gear inchs. A world class kilo rider might hit 2,600 watts in the event. The start is so explosive. You don’t see a lot of enduros riding with straps. I haven’t seen a world class sprinter who doesn’t ride with straps. But, it could be one of those things that riders do because they see other good riders do it.

JohnDThompson 

Just curious: what benefit would a PTFE coating confer on a single-speed/fixed gear drivetrain?

Doge

Lower friction. More r&d going into the larger market. The 11sp chains are more loose. I expect the side plates don't rub as much. The difference between a treated 11 speed and "regular" one can be 100%. I'm not the track chain expert, but the chains seem very plain to me.